1,558 results on '"Deformation Behavior"'
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2. Wave transmittance performance prediction of curved radome prefabricated with continuous fibers plain weave fabric.
- Author
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Yin, Jianjun, Wu, Yilan, Sun, Yong, Yang, Jun, Xiong, Ziliu, and Wu, Kang
- Abstract
Highlights The plain weave fabric made of special fibers was characterized by low density, lightness, ease of co‐planarity, and strong designability, widely used in the production of radar covers, stealth fighter skin, and shielding walls, among other complex electromagnetic shielding components. However, high‐performance fibers, influenced by weaving processes and the interlacing patterns of yarns, possess significant flexibility. Under external loads, fibers are prone to relative slippage, leading to uncertain geometric distortions. Furthermore, changes in their electromagnetic wave transmission properties make it difficult to accurately predict the electromagnetic performance of fiber radar covers. This study primarily focuses on the macro deformation behavior of plain weave fabrics, establishes the geometric mapping relationship for covering curved surface radar covers using plain weave fabrics, and ultimately develops a predictive model for the electromagnetic wave transmittance performance of plain weave fabrics. The research examines the impact of macro and micro geometric structural parameters of plain weave fabrics on electromagnetic wave transmission properties, ultimately enabling quantitative analysis of the electromagnetic wave transmission properties of woven radar covers. The conclusions indicated that changes in the plain weave fabric's pitch directly affect the fiber volume fraction, thereby affecting the transmittance. The greater the shear deformation of plain weave fabric laid on a curved surface, the thicker the fabric and the higher the fiber volume fraction. At the higher curvature ends of curved surfaces, the transmittance was lower than at the lower curvature base. Explained the deformation behavior of plain weave fabric. A wave transmission model for radome made of plain weave fabric was established. The influence mechanism of fabric deformation on wave transmission was revealed. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Understanding deformation and fracture mechanism of Ti-55531 alloy under complex loading conditions: a case of pre-tensioned torsion.
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Hu, Kong-Liang, Huang, Chao-Wen, Zeng, Hong-Tao, Yang, Jiang, Liu, Dan, Li, Tian-Xin, Wan, Ming-Pan, and Zhao, Yong-Qing
- Abstract
Copyright of Rare Metals is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2024
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4. An incremental flanging strategy for small hole with electropermanent magnetic device.
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He, Sicheng, Sun, Yonggen, Zhang, Jiacheng, Meng, Linyuan, Zhang, Teng, and Qin, Siji
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LASER beam cutting , *MAGNETIC circuits , *FINITE element method , *MAGNETIC devices , *SUPERPOSITION principle (Physics) - Abstract
Within the manufacturing industry, hole flanging is an essential process for forming local features in sheet metal. To enhance the flanging height, the diameter of the prefabricated hole should be reduced. However, the undersized diameter of the hole may result in a crack during the flanging process. Combining the electropermanent magnet (EPM) technique with the stamping process, a composite flanging method with incremental feed is proposed to improve sheet forming performance based on the superposition principle of magnetic circuits. Through a symmetric flanging model, the thickness distribution, contour, and forming height of flanging zones are simulated, measured, and found to be reasonably consistent with related theories. The results show that the built model is suitable for investigating flanging deformation behavior. Flanging processing was performed on 304 stainless steel plates with various laser cutting predrilled hole radii. Under various increment rates, the flanging inclination angle is measured and compared through finite element method (FEM) and experiment. Furthermore, when the plate thickness ratio to the prefabricated hole diameter is 0.11, the limit circular hole flanging coefficient can reach 2.22, which is an improvement of 4.83% compared to the traditional flanging process. [ABSTRACT FROM AUTHOR]
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- 2024
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5. Superplastic Deformation Behavior of 2 mm Ti60 Rolled Sheet in Air Environment.
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Dong, Shulin, Qu, Shiwen, Chen, Zhiyong, Qu, Yingdong, Chen, Ruirun, Li, Guanglong, Zhang, Wei, and Liu, Shibing
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STRAIN rate ,CRYSTAL grain boundaries ,ACTIVATION energy ,DEFORMATIONS (Mechanics) ,MICROSTRUCTURE - Abstract
The superplastic deformation behavior of 2 mm Ti60 sheet is studied, and the constitutive equation of superplastic deformation is established. The results show that when the strain rate is 5.00 × 10−3 s−1 and the temperature is 950 °C, the maximum superplastic elongation reaches 400%. Through the analysis of the true strain–true stress curve, it is found that the average apparent activation energy (Q) is 490.783 kJ mol−1 and the average strain rate sensitivity (m) is 0.49. Dynamic spheroidization (DG) promotes the transformation of lath α phase to equiaxed α phase. Dynamic recrystallization (DRX) promotes the generation of high‐angle grain boundaries (θ > 15°). After deformation, the strength of R‐type textures changes significantly. From the grip to the tip, the strength of R‐type texture gradually weakens, which is mainly caused by the rotation of grains during deformation. The deformation mechanism of Ti60 sheet is dominated by grain boundary sliding, and is coordinated by grain growth, DG, DRX, dislocation motion, and grain rotation. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Reinforcement and toughening of the self‐piercing riveted bonded joints induced by the pre‐embedded adhesive in rivet cavities.
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Liu, Jianpeng, Xue, Zhigang, Guo, Pengcheng, Xu, Congchang, and Li, Luoxing
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RIVETED joints , *FINITE element method , *ADHESIVE joints , *ADHESIVES , *RIVETS & riveting , *MICROHARDNESS - Abstract
Highlights Self‐piercing riveted bonded (SPRB) joints are widely used in body‐in‐white (BIW) to connect dissimilar materials owing to their high fatigue and electrochemical performance. However, the strength of the SPRB joint has been found to be inferior to that of self‐piercing riveted (SPR) joints, owing to the reduction in undercut induced by the introduction of an adhesive, especially under pull‐out loading conditions. Interestingly, the mechanical strength improved when the rivet cavity was pre‐embedded with an adhesive. Before the riveting process, the rivet cavities in SPRB joints were pre‐embedded with 0.01, 0.02, and 0.03 mL of adhesive, namely them PSPRB‐V1–V3, respectively. Finite element (FE) models of SPRB and PSPRB joints were developed to analyze their formability and mechanical properties. The simulated and experimental results showed that the hydraulic pressure in the rivet cavity increased as the pre‐embedded adhesive volume in the rivet cavity increased during the riveting process, which further improved the undercut, microhardness, effective bearing area, and mechanical properties of joints. Among the prepared PSPRB joints, the PSPRB‐V3 joint exhibited the best undercut and optimal mechanical properties. Specifically, its undercut and peak force increased by 16.43% and 12.87% compared with those of SPRB joints. These findings provide important guidance for designing steel‐aluminum SPRB joints that require high‐bearing capabilities. The effect of pre‐embedded adhesive on the SPRB joint cross‐section was studied. Failure mechanisms of the SPRB and PSPRB joints were investigated via FEM. The better PSPRB joint performance over SPRB joints was elucidated. The stress–strain history was considered in the FE model of the joint failure process. Strengthening mechanism of pre‐embedded adhesive in the rivet cavity was discussed. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Plastic Workability and Rheological Stress Model Based on an Artificial Neural Network of SiC p /Al-7.75Fe-1.04V-1.95Si Composites.
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Feng, Pinming, Chen, Shuang, Tang, Jie, Liu, Haiyang, Fu, Dingfa, Teng, Jie, and Jiang, Fulin
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ARTIFICIAL neural networks , *MATERIAL plasticity , *ALUMINUM composites , *FINITE element method , *PARTICULATE matter , *HEAT resistant alloys - Abstract
SiCp/Al-Fe-V-Si composites exhibit complex deformation behaviors at both room and high temperatures because of the presence of SiC reinforcement particles and numerous fine dispersed Al12(Fe, V)3Si heat-resistant phases. In this work, an artificial neural network (ANN) constitutive model was established to study the deformation behavior of SiCp/Al-7.75Fe-1.04V-1.95Si composites over a wide temperature range based on uniaxial compression. Then, microstructural observation, finite element analysis, and processing maps were utilized to investigate the plastic workability. The results showed that the ANN model fit the experimental stress–strain curves with high accuracy, achieving an R2 value of 0.999. The ANN model was embedded into finite element software to study plastic deformation behaviors, which indicated that this model could accurately compute the plastic and mechanical response during the compressing process. Finally, a thermomechanical processing diagram was developed, revealing that the optimal processing parameters of the SiCp/Al-7.75Fe-1.04V-1.95Si composites were a deformation temperature of 450–500 °C and a deformation rate of 0.1–0.2 s−1. [ABSTRACT FROM AUTHOR]
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- 2024
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8. Hot deformation behavior and dynamic recrystallization of 2195 Al–Li alloy with various pre-precipitation microstructures.
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Fu, Rong, Shao, Hongbang, Huang, Yuanchun, Liu, Yu, and Li, Hui
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In this work, 2195 Al–Li alloys with various precipitation microstructures were obtained by homogenization treatment followed by air-cooling (AC), discontinuous cooling (DC), and furnace-cooling (FC), and then tested by hot compression at different temperatures. The results show that the flow stresses of all specimens decrease with temperature and the peak stresses of AC, DC and FC specimens decrease in order at the same temperature. For FC samples, coarse pre-precipitates diminish the deformation resistance due to the reduction of solid solution strengthening and precipitation strengthening. Dynamic softening at low temperatures is significantly greater than that at high temperatures, except for the anomalous softening of the FC specimen at 520 °C due to stress release by cracks. At 370–420 °C, the dynamic softening of the AC specimen is more significant than the other samples, resulting from dynamic precipitation and precipitate coarsening. Furthermore, there is considerable dynamic recrystallization (DRX) in FC samples and not in AC and DC samples, although their precipitates coarsen to similar levels at low temperatures. This suggests that DRX is associated with the particle-stimulated nucleation mechanism by regularly arranged precipitates. The banded or regularly arranged precipitates divide the Al matrix into multiple confined units, hindering dislocations and (sub)grain boundary movement, and thus promoting the development of sub-grains and DRX. [ABSTRACT FROM AUTHOR]
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- 2024
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9. Investigation on deformation behavior and bearing capacity of a segmental ring based on the horizontal convergence.
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Yuan, Qiang, Zhao, Xu, Li, Yang, and Yuan, Bingxiang
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TUNNEL design & construction , *WATER leakage , *GEOMETRICAL constructions , *NUMERICAL analysis , *DEFORMATIONS (Mechanics) - Abstract
In this study, a refined numerical model, which contains the detailed geometric construction of the longitudinal joints, is established to investigate the bearing performance of the segmental ring based on the horizontal convergence. Firstly, the model is verified by comparing it with the reported results of a documented full‐scale model test. Then, according to the load‐structure method, this numerical model is employed to investigate the deformation behavior and bearing capacity of the segmental ring. Moreover, the effects of the coefficient of lateral pressure and subgrade reaction are extensively taken into consideration through comprehensive numerical analyses. According to the numerical results, a bilinear model is proposed to describe the relation between the convergent displacement and the stratum pressure, which could be used to preliminarily estimate the convergence after the completion of tunnel construction. Otherwise, the development of structural defects, such as the joint opening and the water leakage, has close association with the horizontal convergence. Therefore, a simple evaluation method for tunnel structure safety assessment is proposed using horizontal convergence deformation as an indicator to predict the tunnel service state. Since this indicator is easy to obtain during the tunnel operation, it is convenient for the engineers to assess the bearing capacity of the segmental ring and the service state of the tunnel structure quickly. [ABSTRACT FROM AUTHOR]
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- 2024
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10. Investigation on pulse current-assisted stationary shoulder friction stir welded Ti-6Al-4 V joints.
- Author
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Jiang, Wang, Li, Chaojiang, Yuan, Tao, Chen, Shujun, Xiaoqing, Jiang, and Bai, Yafeng
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FRICTION stir welding , *FRICTION welding , *DUCTILE fractures , *DEFORMATIONS (Mechanics) , *CRYSTAL grain boundaries - Abstract
In this study, we investigated the effect of pulse current on the microstructure, texture, deformation behavior, and mechanical properties of Ti-6Al-4 V alloys fabricated by electrically assisted stationary friction stirring welding. With the increase of the rotation speed and peak pulse current, a lamellar structure precipitated in the stir zone became more elongated, resulting in a higher concentration of grain orientation distribution and a larger but gradually decreasing ratio of high-angle grain boundaries. Moreover, the texture strength increased, but still remained lower than that of the transition zone on both sides. The microhardness distribution of the welded joint was anisotropic in all layers, with the stir zone exhibiting the highest hardness, while the HAZ was identified as the weakest region. The joints have a maximum tensile strength of 1020.1 MPa and an elongation of 6%, respectively. The tensile strength is comparable to that of the base metal (BM), and the elongation reaches 57.7% of BM. This improvement is mainly attributed to grain refinement and uniformly distributed hardness. Furthermore, all tensile fractures were ductile fractures. [ABSTRACT FROM AUTHOR]
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- 2024
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11. Deformation mechanism of glass microlenses and microlens arrays in contactless hot embossing.
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Yang, Kang, Li, Jianzhi, Gong, Feng, and Yang, Gao
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OPTICAL glass , *MICROLENSES , *GLASS , *UNIFORMITY , *CURVATURE - Abstract
Contactless hot embossing has been demonstrated to possess the potential for cost‐effective production and precise mounting concepts in fabricating glass microlenses and microlens arrays due to the reduced difficulty of mold fabrication and the possibility of obtaining self‐aligned assemblies. This study aims to provide experimental evidence for understanding the forming mechanism of glass microlenses and microlens arrays in the contactless hot embossing process. The effects of process parameters, diameter and position of the micro‐holes, hole diameter, and pitch of the micro‐hole array mold on the filling deformation of glass in contactless hot embossing were comprehensively investigated. It is found that placing the micro‐hole farther away from the mold center renders decrease in both filling height and tip curvature but increase in the eccentricity of the embossed glass microlens. As a result, the formed glass microlens array shows a nonuniform distribution of filling height and tip curvature. Furthermore, reducing the pitch of micro‐hole array mold can significantly improve the uniformity of formed microlens array. Based on these experimental results, the forming mechanism of microlenses and microlens arrays in contactless hot embossing process is summarized. Finally, a glass microlens array with decent uniformity in the center area was hot embossed by using a SiC micro‐hole array mold. [ABSTRACT FROM AUTHOR]
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- 2024
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12. Investigation of the Role of the Initial Workpiece Diameter in Deformation Control in Electromagnetic Sheet Forming.
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Chen, Meng, Xiao, Hanchen, Wang, Zuoshuai, Wang, Jianxun, Zuo, Chao, and Yang, Wentie
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METALWORK ,SHEET metal ,STRENGTH of materials ,GEOMETRIC shapes ,DEFORMATIONS (Mechanics) - Abstract
The initial workpiece diameter is one of the most fundamental process parameters in sheet metal forming, as it determines the resistance of the draw-in material flow. In the context of conventional deep drawing, its critical role has been clearly identified. In the context of electromagnetic sheet forming, however, its role has not yet been adequately addressed. This paper aims to clarify its role, by experimentally and numerically investigating the deformation behavior of circular sheet metal in electromagnetic forming. Various combinations of the initial diameter and discharge voltage were established to induce different deformation behaviors. It was found that adjusting the initial diameter can substantially change the forming height, shape, and thickness distribution by altering the draw-in, which suggests a great improvement in deformation controllability. In summary, this study demonstrates that the initial workpiece diameter could play critical role in deformation control in electromagnetic forming. [ABSTRACT FROM AUTHOR]
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- 2024
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13. 碳纤维与玄武岩纤维网格增强ECC 复合板的单轴抗拉性能研究.
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郭彩霞, 周 博, 王国盛, 路德春, and 杜修力
- Abstract
Copyright of Tunnel Construction / Suidao Jianshe (Zhong-Yingwen Ban) is the property of Tunnel Construction Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2024
- Full Text
- View/download PDF
14. Study on theoretical model and actual deformation of weft-knitted transfer loop based on particle constraint
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Jing Zhang and Honglian Cong
- Subjects
weft-knitted transfer fabric ,particle system ,geometric model ,deformation behavior ,continuity ,Textile bleaching, dyeing, printing, etc. ,TP890-933 - Abstract
In order to derive the structural properties and deformation behavior of the weft-knitted transfer fabric, a multilayer spring-mass geometric circle model with weft-knitted transfer loop is provided in conjunction with the fabric samples’ image. Eight type-value points were utilized to control the transfer loop’s morphological structure. Connections between the type-value points and the particle system were established. Non-uniform rational B spline curves and texture mapping were utilized to create the three-dimensional impression of the weft-knitted transfer loop. By measuring the offset of the type-value points in conjunction, the actual deformation of the weft-knitted transfer fabric was determined. Utilizing a cylindrical envelope box for collision detection, the possible unreasonable interpenetration phenomenon in the simulation was solved, and thus a stable weft-knitted transfer loop structure was obtained. Using Microsoft Visual Studio and C#, the deformation of the weft-knitted transfer fabric was simulated, the simulated weft-knitted transfer fabric’s deformation pattern accurately depicts the fabric’s three-dimensional structure and deformation behavior while also matching the structural characteristics of the fabric sample. The findings demonstrate that the theoretical structural model of weft-knitted transfer fabric constructed can accurately represent the loop’s structure, and the actual deformation of the simulated weft-knitted transfer fabric is consistent with the deformation characteristics of the fabric sample. Weft-knitted transfer fabric’s deformation behavior may be effectively reflected by the multilayer spring-mass geometric circle model, allowing for the modeling of the fabric’s morphology and 3D structure.
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- 2024
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15. Numerical Modeling Behavior of Split Hopkinson Pressure Bar of Additively Manufactured Ti6Al4V
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Keshavarzana, Mohsen, Alaghmandfard, Reza, Forooghi, Foroozan, Mohammadi, Mohsen, and Metallurgy and Materials Society of CIM, editor
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- 2025
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16. New strategy for efficient manufacturing of bulk anisotropic nanocrystalline Nd-Fe-B permanent magnets.
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Li, Qian, Liu, Lingqi, Li, Yuqing, Yue, Ming, Teng, Yuan, Liu, Weiqiang, and Zhang, Dongtao
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MAGNETIC particles ,HOT rolling ,PERMANENT magnets ,MAGNETIC properties ,HOT pressing - Abstract
• For the first time, fully dense Nd-Fe-B precursors were prepared by hot rolling. • The large-size hot-rolled Nd-Fe-B magnet has excellent homogeneity. The hot-rolled magnets undergo densification and deformation simultaneously. • The microstructural evolution of hot rolling and hot deformation was systematically investigated. • Dissolution-precipitation, anisotropic grain growth, and regular grain arrangement were the deformation mechanisms. • The hot rolling technology enables the industrial production of anisotropic nanocrystalline Nd-Fe-B magnets. The application of bulk nanocrystalline Nd-Fe-B permanent magnets manufactured by hot deformation methods was severely limited by production efficiency. Therefore, this work proposed an efficient preparation method combining hot rolling and deformation. Using the melt-spun Nd-Fe-B magnetic powders as original materials, dense, large-sized, and well-uniform precursors for deformation can be obtained through cold pressing and hot rolling. The large-sized hot-rolled magnet can be cut into small pieces and subjected to hot deformation. The deformed magnet exhibits obvious crystallographic anisotropy, and the optimal maximum energy product can reach 35.7 MGOe. Furthermore, the mechanism of deformation and texture formation has been systematically studied, according to the microstructure and texture characterization of different height reduction magnets. The results indicated that there was a typical heterogeneous structure in the hot-rolled and hot-deformed Nd-Fe-B magnets. Dissolution precipitation, grain growth, and regular grain arrangement were the main reasons for deformation and texture formation during the deformation process. Our strategy of replacing traditional hot-pressing with large-sized hot-rolling can produce massively deformed precursors at once, greatly improving production efficiency, which is crucial for promoting the application of bulk nanocrystalline anisotropic Nd-Fe-B permanent magnets. [Display omitted] [ABSTRACT FROM AUTHOR]
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- 2024
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17. Micromechanics in Mg alloys: Role of hard Al2RE precipitates.
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Su, Hui, Wang, Junsheng, Xue, Chengpeng, Tian, Guangyuan, Wang, Shuo, Yang, Xinghai, Li, Quan, Miao, Yisheng, Yang, Zhihao, and Meng, Yanan
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DISLOCATION density ,CRYSTAL models ,ELASTIC modulus ,MICROMECHANICS ,MICROCRACKS ,RARE earth metals ,RARE earth oxides - Abstract
• Effects of hard/soft Al 2 RE phases on damage behaviors of Mg alloys have been uncovered by using a CPFEM model. • Microscale damage mechanisms have been found by DIC tests and Al 2 RE quantifications using TEM and 3D XCT. • Crystal plasticity model based on dislocation density proves crack initiation at Al 2 RE phases. • CPFEM predicts stiffer Al 2 RE having better damage resistance than soft ones matching SEM fracture analysis. The influence of hard Al 2 RE phases (Sc , Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) on the overall and local deformation as well as damage mechanism of Mg alloys has been studied by using a crystal plasticity model based on dislocation density with a brittle damage criterion. Microcracks that lead to swift damage initiation and propagation throughout the matrix have been predicted. It has been found that the hard Al 2 RE with higher elastic modulus enhances the damage resistance of the Mg matrix, which was confirmed by fracture SEM/EDS characterizations and phase-field damage simulation. This discovery provides valuable insights for designing Mg alloys with both high stiffness and enhanced damage resistance. [Display omitted] [ABSTRACT FROM AUTHOR]
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- 2024
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18. Research on deformation behavior, microstructure evolution and phase transformation of ultra-light LA93-1(La/Ce) alloy
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Kun Yang, Bin Li, Hao Chen, Guo Li, Guobing Wei, and Xiaodong Peng
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Microstructure evolution ,Strain-induced transformation ,Thermal processing map ,Deformation behavior ,Mining engineering. Metallurgy ,TN1-997 - Abstract
Isothermal compression tests were conducted out on the Mg–9Li–3Al-1(La/Ce) (wt.%) alloy under different deformation parameter through a Gleeble-3500 thermal-mechanical simulator. The flow curves at high strain rates exhibit a ''serrated flow”, which is a dynamic strain aging behavior. R = 0.9253 and AARE = 7.64% quantified the accuracy of the constitutive equations, indicating that this equation has reliable predictive ability. The thermal processing maps indicated that the safe processing region is T = 537–623 K, ε˙ = 0.041–0.001 s−1. This alloy has excellent formability. When deformation is at T = 473 K, ε˙ = 1 s−1, there are more deformed grains in two phases, and broken β-Li grains distributed in chains along the RD. In addition, some α-Mg phases precipitated from the β-Li phase, distributed along the β-Li grain boundaries, and they were dominated by recrystallized grains with low dislocation density. High-density dislocation regions located both at the grain boundaries and inside the grains. When deformation is at T = 473 K, ε˙ = 0.01 s−1, all the deformed grains in two phases decreased with decreasing strain rate, and they transformed more into substructures. The high-density dislocation regions inside the grains gradually disappear. Additionally, the size of precipitated α-Mg phase increased slightly, which is still predominantly located at the grain boundaries. When deformation is at T = 623 K, ε˙ = 0.01 s−1, the degree of recrystallization increases significantly with increasing temperature. The high-density dislocation regions almost disappeared. Interestingly, large amounts of α-Mg grains precipitated inside the β-Li grains.
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- 2024
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19. Research on deformation behaviors at different temperatures of lean duplex stainless steel S32101 produced by direct cold rolling process
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Xinghai Zhang, Chao Yang, Haofei Zhu, Zhiping Xiong, and Xingwang Cheng
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Lean duplex stainless steel ,Cryogenic mechanical properties ,Deformation behavior ,TRIP effect ,Mining engineering. Metallurgy ,TN1-997 - Abstract
In this paper, the mechanical properties, work hardening characteristics and deformation mechanism of lean duplex stainless steel (LDSS) S32101 produced by direct cold rolling were studied under different temperature conditions. The yield strength (YS) and tensile strength (TS) of S32101 decreased with the increase of deformation temperature, while the elongation increased first and then decreased. The TS of S32101 at −70 °C was 1052.6 MPa, the elongation remained 57.2%, and the product of strength and elongation (PSE) was as high as 60.2 GPa·%, which was mainly due to the synergistic strengthening of transformation induced plasticity (TRIP) and twinning-induced plasticity (TWIP) effects in austenite at cryogenic temperatures. The efficiency of grain refinement at cryogenic temperature was improved by TRIP effect and deformation twins (DTs), indicating that it had the potential to be applied at low temperature (−70 ∼ −30°C). Moreover, the high density nanotwins and the strong interaction between the dislocation and nanotwin bundles also contributed to strain hardening at low temperatures and thus better comprehensive mechanical properties could be achieved.
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- 2024
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20. Cryogenic deformation behavior, constitutive modeling and microstructure evolution of solution-treated 2195 Al–Li alloy at high strain rates
- Author
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Yixi Chen, Junquan Yu, Xiqing Ge, Yutong Sun, Lu Sun, Wenbin Zhou, and Guoqun Zhao
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2195 Al–Li alloy ,Deformation behavior ,Constitutive equation ,Deformation band and dislocation ,Precipitation strengthening ,Mining engineering. Metallurgy ,TN1-997 - Abstract
In this paper, the flow behavior, constitutive model and microstructure evolution of solution-treated 2195 Al–Li alloy at temperatures from 123 K to 298 K and strain rates from 2000 s−1 to 5000 s−1 were studied. Experimental results show that the flow stress of the solution-treated 2195 Al–Li alloy is more sensitive to deformation temperature than strain rate. As the temperature declines from 298 K to 123 K, the flow stress at 2000 s−1 and 5000 s−1 increases by nearly 32.8% and 34.5%, respectively; whereas as the strain rate increases from 2000 s−1 to 5000 s−1, the flow stress at 298 K and 123 K only increases by 5.1% and 6.5%, respectively. The average strain hardening rate tends to decline with the increase in strain rate and temperature, and its value at 123 K and 2000 s−1 is about 1.5 times greater than that at 298 K and 5000 s−1. To overcome the very limited applicability of the conventional Arrhenius model with strain compensation, an Arrhenius-based model (c-Arrhenius model) is developed by coupling an independent strain term and then derived by using normalized flow stress and linear regression. To quantify the strain rate effect and temperature effect, a Johnson-Cook-based model (c-Johnson-Cook model) with exponential terms is developed. These two new constitutive models are validated via a comparative analysis, showing good predictability and accuracy. A further microstructure observation shows that the dislocation density is the highest at a strain rate of 5000 s−1 and cryogenic temperature of 123 K, which is beneficial for subsequent aging strengthening.
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- 2024
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21. Influence of Immersion Orientation on Microstructural Evolution and Deformation Behavior of 40Cr Steel Automobile Front Axle during Oil Quenching.
- Author
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Shi, Yuanji, Wang, Xiaowen, Dong, Chengtong, Li, Junwan, Chen, Zeyu, and Cheng, Cheng
- Subjects
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AUTOMOBILE axles , *FINITE element method , *MARTENSITE , *HEAT transfer , *MICROSTRUCTURE - Abstract
This study employs the finite element method to investigate the microstructural evolution and deformation behavior of a 40Cr steel automobile front axle during the quenching process. By establishing a multi-physics field coupling model, the study elucidates the variation patterns of the microstructure field in the quenching process of the front axle under different immersion orientations. It is found that along the length direction, the bainite and martensite structures decrease from the center to the edge region, while the ferrite structure shows an increasing trend. Additionally, the influence of immersion orientation on the hardness of the front axle's microstructure and deformation behavior is thoroughly discussed. The results indicate that, firstly, when quenched horizontally, the hardness difference among different regions of the front axle is approximately 8.2 HRC, whereas it reaches 10.3 HRC when quenched vertically. Considering the uniformity of the microstructure, the horizontal immersion method is preferable. Secondly, due to the different immersion sequences in different regions of the front axle leading to varying heat transfer rates, as well as the different amounts of martensite structures obtained in different regions, the deformation decreases along the length direction from the center to the edge region. Horizontal immersion quenching, compared to vertical immersion, results in a reduction of approximately 56.2% and 48.9% in deformation on the representative central cross-section (A-A) and the total length of the front axle, respectively. Therefore, considering aspects such as microstructure uniformity and deformation, the horizontal immersion quenching orientation is more favorable. [ABSTRACT FROM AUTHOR]
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- 2024
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22. Investigating the thermo-hydro-mechanical behavior of loess subjected to freeze–thaw cycles.
- Author
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Bai, Ruiqiang, Lai, Yuanming, Zhang, Mingyi, and Jiang, Haoyuan
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FROST heaving , *DRINKING (Physiology) , *LOESS , *WATER transfer ,COLD regions - Abstract
The stability and performance of loess infrastructure in cold regions are often challenged by seasonal freezing–thawing action. The action of the foundation loess is a complex thermo-hydro-mechanical coupling process, and it is crucial to understand this process for the loess infrastructure in cold regions. A series of controlled tests were conducted to observe the changes in temperature, moisture, and frost heave variations within loess samples under freezing–thawing, and the influences of cycle period, freezing–thawing amplitude, and cycle number on the thermo-hydro-mechanical behavior of loess were investigated. The results reveal that freeze–thaw cycles significantly affect the heat transfer, water migration, and deformation of the loess. The temperatures of sample at different heights periodically vary under freezing–thawing. Water is absorbed to the samples, which undergoes a rapid water intake stage, a water drained stage, and a slow water intake stage under freezing–thawing, resulting in moisture redistribution in loess. Loess undergoes frost heave, thaw settlement, and consolidation processes during freezing–thawing, and a slight wetting collapse may occur after several freezing–thawing cycles. Within the same cycle, frost heave is the largest while consolidation deformation is the smallest. Frost heave and consolidation deformation reach their maximum values at the second cycle, whereas thaw settlement reaches its maximum value during the second or third cycle. Each stage deformation increases with an extended cycle period and almost decreases as the freezing–thawing amplitude increases. Freeze–thaw cycles can induce wetting collapse of loess, resulting in negative residual deformation. Furthermore, the thermo-hydro-mechanical coupling process and the deformation mechanism of loess have been elucidated. These insights contribute to a more comprehensive understanding of the failure mechanisms in loess engineering in cold regions. [ABSTRACT FROM AUTHOR]
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- 2024
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23. Influence of Cyclic Amplitude of Deviatoric Stress on Deformation Behavior of Saturated Sand under Different Stress Paths.
- Author
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Zhao, Zhiyi, Deng, Gang, Zhang, Yinqi, Zhang, Zhaopeng, Guo, Qinqin, and Zhang, Hongping
- Subjects
- *
STRAINS & stresses (Mechanics) , *BUILDING foundations , *AXIAL stresses , *LOADING & unloading , *CYCLIC loads , *SHEAR strain , *SAND - Abstract
Under various stress paths, the deformation characteristics represented great differences. In this paper, a series of cyclic triaxial tests have been conducted with Fujian standard sand. By comparing the constant deviatoric (CDS) and constant axial stress paths (CAS), the influence mechanism of the cyclic amplitude of the deviatoric stress was discussed. The test results showed that the stress path significantly influenced the volumetric and shear strains. The increasing and decreasing trend in the volumetric strain (ɛv) was consistent with the spherical stress (lnp). Compared with the two stress paths, the slope of the ɛv−lnp curve during the loading and unloading stages was larger under the CAS path. In the CDS path, qc almost did not affect the cumulative volumetric strain, and in the CAS path, the effect was obvious. The shear strain curve was in accordance with the direction of the stress path. As the cyclic number increased, the shear strain gradually accumulated. The shear strain accumulation under the CAS path was larger. The shear strain largely depended on the relative position between the critical state line (CSL) and the stress state of the soil during cyclic loading and unloading. Practical Applications: In practical engineering, the soil will experience various stress paths. For example, in slope or earth–rock dam engineering, where the water level rises and falls repeatedly, the soil often goes through the stress path of constant deviational stress with the cyclic increase and decrease in the spherical stress. In foundation pit engineering, the soil often experiences the stress path of the constant axial stress (CAS) with cyclic loading and unloading of the lateral stress. The stress path greatly influences the deformation and strength of soil. Therefore, the previous two stress paths are compared in this paper to discuss the influence of the cyclic amplitude of deviatoric stress. Under three different consolidation states, the cyclic amplitude of the deviatoric stress significantly influenced the volumetric and shear strains. The shear strain largely depended on the relative position between the critical state line (CSL) and the stress state of the soil during cyclic loading and unloading. Therefore, in practical engineering, if the stress path in the experiment differs from the actual value, the influence of the stress path should be properly considered. The results should be modified according to the degree of influence of each stress condition. [ABSTRACT FROM AUTHOR]
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- 2024
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24. Unraveling the Mechanical Response of Short-Chain Branched Amorphous Polyethylene: Insights from Molecular Dynamics Simulations.
- Author
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Shi, Jingfu, Zhou, Jia, Liu, Lei, and Miao, Changqing
- Abstract
AbstractThe deformation behavior of short-chain branched, amorphous polyethylene (PE) was investigated using united atom molecular dynamics (MD) simulations under uniaxial stretching. Our research reported in this paper examined the internal mechanisms underlying the mechanical response of the PE by analyzing potential energies, dihedral angle distributions, chain orientation and entanglements. The findings indicated that the short-chain branching generally enhanced Young’s modulus, except for sample B60 with a critical ethyl branch content of 60/1000 (60 ethyl branches per 1000 backbone carbons). The Young’s modulus of B60 was the local minimum value in the various samples. Analysis of the evolution of dihedral angles shows that the short-chain branching hinders the transition from gauche to trans configurations, leading to a decrease in the trans population as the branch content increases. Regarding the sample B60 with critical branch content 60/1000, the orientation parameter and entanglement parameter of the molecular chains along the backbone were lowest in the initial structure, and the efficiency of chain disentanglement was at its lowest during deformation. The simulation results elucidated the deformation mechanism related to the conformational evolution of the molecular chains, which can provide atomic-scale insights into the mechanical properties and processability of branched polyethylene, thereby allowing for optimization in its design and application. [ABSTRACT FROM AUTHOR]
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- 2024
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25. Simultaneous Necking and Barreling Deformation Behaviors in Bending of Single-Crystal Gold Micro-Cantilever.
- Author
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Fujita, Kazuya, Suzuki, Kosuke, Asano, Keisuke, Chen, Chun-Yi, Kurioka, Tomoyuki, Machida, Katsuyuki, Ito, Hiroyuki, Miyake, Yoshihiro, Sone, Masato, and Chang, Tso-Fu Mark
- Subjects
- *
YIELD stress , *BEND testing , *MICROCANTILEVERS , *DEFORMATIONS (Mechanics) , *SAMPLE size (Statistics) - Abstract
Necking and barreling deformation behaviors occurred simultaneously during the bending test of a single-crystal gold micro-cantilever (sample A) with the loading direction parallel to the [1-10] orientation and the neutral plane parallel to the [110] orientation. In contrast, for another single-crystal gold micro-cantilever, sample B, with the loading direction aligned parallel to the [0.37 −0.92 0.05] orientation and the neutral plane parallel to the [0.54 0.28 0.78] orientation, predominant slip band deformation was noted. Sample A exhibited activation of four slip systems, whereas sample B demonstrated activity in only a single-slip system. This difference suggests that the presence of multiple slip systems contributes to the concurrent occurrence of necking and barreling deformations. Furthermore, variations in the thickness of the micro-cantilevers resulted in observable strengthening, indicating that the effect of sample size is intricately linked to the geometry of the cross-section, which we have termed the "sample geometry effect". [ABSTRACT FROM AUTHOR]
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- 2024
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26. 钢筋混凝土的负泊松比设计与抗高速冲击性能.
- Author
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刘 进, 张 芸, 马衍轩, 李梦瑶, 王 鹏, 张 建, 王公斌, 张 鹏, and 高 嵩
- Abstract
Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2024
27. Inverse Estimation of Material Model Parameters Using Digital Image Correlation and Ensemble-Based Four-Dimensional Variational Methods.
- Author
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Sae Sueki, Akimitsu Ishii, and Akinori Yamanaka
- Subjects
DIGITAL image correlation ,MATERIALS testing ,TENSILE tests ,ALUMINUM alloys ,DIGITAL images ,DISPLACEMENT (Mechanics) - Abstract
The prediction accuracy of the deformation behavior of materials by finite element (FE) simulation depends on the parameters in selected material models. Although the parameters are conventionally identified from standard material tests (e.g., uniaxial tensile and multiaxial material tests) to characterize the deformation behavior, the identification process requires a large number of experiments. We develop a novel inverse methodology for estimating the material model parameters by combining digital image correlation (DIC) measurement and FE simulation coupled with an ensemble-based four-dimensional variational method (En4DVar). En4DVar incorporates the experimental data obtained from a material test into the FE simulation that reproduces the test and inversely estimates the parameters such that the simulation results follow the experimental data, allowing for the reduction of experimental effort. We use the proposed method to estimate the parameters of a strainhardening law and anisotropic yield function from the results of uniaxial tensile test of a round bar of aluminum alloy. DIC measurement is conducted to obtain experimental data of the three-dimensional displacement and strain field over the surface of the specimen, including the post-necking range. The results demonstrate that En4DVar is a promising method for inversely estimating the parameters and characterizing the deformation behavior of a material from the results of a small number of tests. [ABSTRACT FROM AUTHOR]
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- 2024
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28. Preparation, Deformation Behavior and Irradiation Damage of Refractory Metal Single Crystals for Nuclear Applications: A Review.
- Author
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Jiao, Benqi, Han, Weizhong, Zhang, Wen, Hu, Zhongwu, and Li, Jianfeng
- Subjects
- *
HEAT resistant alloys , *METAL crystals , *CRYSTAL orientation , *MECHANICAL properties of metals , *SINGLE crystals - Abstract
Refractory metal single crystals have been applied in key high-temperature structural components of advanced nuclear reactor power systems, due to their excellent high-temperature properties and outstanding compatibility with nuclear fuels. Although electron beam floating zone melting and plasma arc melting techniques can prepare large-size oriented refractory metals and their alloy single crystals, both have difficulty producing perfect defect-free single crystals because of the high-temperature gradient. The mechanical properties of refractory metal single crystals under different loads all exhibit strong temperature and crystal orientation dependence. Slip and twinning are the two basic deformation mechanisms of refractory metal single crystals, in which low temperatures or high strain rates are more likely to induce twinning. Recrystallization is always induced by the combined action of deformation and annealing, exhibiting a strong crystal orientation dependence. The irradiation hardening and neutron embrittlement appear after exposure to irradiation damage and degrade the material properties, attributed to vacancies, dislocation loops, precipitates, and other irradiation defects, hindering dislocation motion. This paper reviews the research progress of refractory metal single crystals from three aspects, preparation technology, deformation behavior, and irradiation damage, and highlights key directions for future research. Finally, future research directions are prospected to provide a reference for the design and development of refractory metal single crystals for nuclear applications. [ABSTRACT FROM AUTHOR]
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- 2024
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29. Microcrystalline Cellulose—A Green Alternative to Conventional Soil Stabilizers.
- Author
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Arun, Lazar, Sujatha, Evangelin Ramani, Baldovino, Jair Arrieta, and Nuñez de la Rosa, Yamid E.
- Subjects
- *
SOIL conditioners , *GELLAN gum , *CLAY soils , *CARBON offsetting , *CARRAGEENANS , *KAOLIN , *XANTHAN gum - Abstract
Biopolymers are polymers of natural origin and are environmentally friendly, carbon neutral and less energy-intense additives that can be used for various geotechnical applications. Biopolymers like xanthan gum, carrageenan, chitosan, agar, gellan gum and gelatin have shown potential for improving subgrade strength, erosion resistance, and as canal liners and in slope stabilization. But minimal research has been carried out on cellulose-based biopolymers, particularly microcrystalline cellulose (MCC), for their application in geotechnical and geo-environmental engineering. In this study, the effect of MCC on select geotechnical properties of kaolin, a weak, highly compressible clay soil, like its liquid and plastic limits, compaction behavior, deformation behavior, unconfined compression strength (UCS) and aging, was investigated. MCC was used in dosages of 0.5, 1.0, 1.5 and 2% of the dry weight of the soil, and the dry mixing method was adopted for sample preparation. The results show that the liquid limit increased marginally by 11% but the plasticity index was nearly 74% higher than that of untreated kaolin. MCC rendered the treated soil stiffer, which is reflected in the deformation modulus, which increased with both dosage and age of the treated sample. The UCS of kaolin increased with dosage and curing period. The maximum UCS was observed for a dosage of 2% MCC at a 90-day curing period. The increase in stiffness and strength of the treated kaolin with aging points out that MCC can be a potential soil stabilizer. [ABSTRACT FROM AUTHOR]
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- 2024
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30. Numerical modeling of industrial parts manufacturing using electromagnetic hemming process.
- Author
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Boutana, Ilhem, Bousba, Abderrahmane, and Benhadj, Yaakoub Nadjari
- Subjects
- *
FINITE element method , *ALUMINUM forming , *METALWORK , *SHEET metal , *ELECTROMAGNETIC devices , *ALUMINUM sheets - Abstract
In the contemporary times, electromagnetic forming process (EMF) is one of the most attractive high-velocity forming methods that can be used in order to achieve many industrial applications in sheet metal forming. Taking into account the advantages and limitations of EMF, this technology is highly used in the automotive industry and has increasing potential applications such as Flanging, Bending, and Hemming processes. Hemming is the process that bends the edges of sheets and serves to increase their stiffness and improve their appearance. In this paper, we aim to investigate the simulation of forming Aluminum sheets using electromagnetic hemming process in order to enhance our understanding of the process and its efficiency, particularly in industrial applications used for automotive panel production. Specifically, an electromagnetic bulging device serves as the fundamental setup for our various applications. This study undertakes multiple numerical simulations using the finite element method to explore the impact of process parameters on the deformed sheet. Additionally, we investigate the temperature distribution across the sheet during hemming. The numerical results demonstrate strong agreement with experimental data and existing research. [ABSTRACT FROM AUTHOR]
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- 2024
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31. Laser shock incremental forming by employing high repetition rate laser pulses with pulse duration in the scale of 100 ns.
- Author
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Shen, Tao, Zhao, Xiaoxiao, Li, Jian, Tian, Ziwei, Yu, Xiaodi, Fan, Fan, and Hong, Wei
- Subjects
- *
LASER pulses , *STRAIN rate , *LASERS , *HOMOGENEITY , *DEFORMATIONS (Mechanics) , *ALUMINUM foil - Abstract
Laser shock forming is an advanced method with characteristics of ultra-high strain rates up to 106–107 s−1 for deformation of micro/nanostructures on foils. However, the former related studies mainly focused on the laser shock forming with large laser spots, short pulse duration, and low repetition rate, which has many limitations in deformation homogeneity and processing efficiency. In this study, a laser shock incremental forming with small laser spot, long pulse duration, and high repetition rate is investigated. To demonstrate the feasibility of this method, a rectangular bulge on an aluminum foil is fabricated. By analyzing the cross-section profiles and average heights at eight different locations in the bulge and comparing them with the reference, the uniformity of the present laser shock incremental forming is investigated. The heat accumulation effect under the action of laser with high repetition rate was analyzed by means of theoretical calculation and analytical comparison. And the deformation behavior of the foil in laser shock incremental forming was simulated by using Abaqus software. Results show that the laser shock incremental forming with small laser spot, long pulse duration, and high repetition rate can be used to deform aluminum foil in thickness of 10 μm. The height of the micro bulge deformed by a laser with a pulse duration of 100 ns and a lower pulse energy can reach a scale similar to that deformed through a larger laser spot with pulse duration of 10 ns. And heat accumulation effect may exist in high repetition rate laser, but it is not the main factor affecting the forming depth. [ABSTRACT FROM AUTHOR]
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- 2024
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32. Modeling of sodiation-induced deformation of Sn anode based on the stress-driven nonlocal integral elasticity.
- Author
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Zhu, Zuoquan, Lv, Mengmeng, Liu, Zongchao, and Wan, Jing
- Subjects
- *
ELASTICITY , *ANODES , *TIN , *DEFORMATIONS (Mechanics) , *FINITE element method , *ELASTIC modulus - Abstract
The anode material Sn used in sodium-ion batteries displays high theoretical capacity, complex phase transformation, and significant volume change during the charging/discharging process. In particular, the effects of small scale on the mechanical behavior of Sn anode at the nanoscale are very active research fields. However, the majority of these results are based on nonlocal gradient formulations. In this study, we proposed and established a model that combines the electrochemical reaction with stress-driven nonlocal integral elasticity for the nanoelectrode to analyze the evolution of diffusion-induced deformation during the sodiation process. Several critical features, such as the small-scale parameter, two-phase reaction, and concentration-dependent elastic modulus, were incorporated into the established model. The model demonstrated that a small scale could significantly affect the deformation behavior. The results obtained using the finite element method showed that the mechanical reliability of the Sn anode could be significantly enhanced when the anode was sodiated with larger nonlocal parameters and smaller slenderness. In addition, the axial action force exhibited a strong size effect and was influenced by the nondimensional thickness parameter of the anode. This work provides a framework for multi-scale research on high-capacity sodium-ion battery electrodes. [ABSTRACT FROM AUTHOR]
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- 2024
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33. Investigation of tensile deformation behavior of a TWIP/TRIP metastable β titanium alloy at typical temperature part Ⅱ: 20 K
- Author
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Y.B. Zhang, S.W. Xin, T. Li, G.J. Zhang, and B.K. Zhao
- Subjects
Metastable β-Ti alloy ,Cryogenic temperature ,Tensile properties ,Deformation behavior ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
The tensile behavior and deformation mechanism of Ti-10Mo alloy at liquid hydrogen temperature (20 K) were investigated. The results showed that Ti-10Mo alloy has a high UTS of 1553 MPa and a high YS of 1497 MPa at 20 K, as well as an excellent elongation after fracture of 11 %. This is due to the simultaneous activation of {332} twin twins and SIM α“ transformation during deformation, that is, the combination of TWIP and TRIP effects. The activation sequence of different deformation mechanisms is as follows: the primary SIM α” and {332} twins are first activated simultaneously. With the increase of strain, multiple variants of SIM α“ and {332} twins can be activated in a grain. Then the primary SIM α” can be further transformed into {130}α“ twins. With the further increase of strain, some {130}α” twins can continue to be transformed into secondary {332}β twin and some primary {332} twins can also produce secondary α“ to continue the deformation. When necking, a large number of {111}α” twins are activated to further coordinate the plastic deformation. In addition, the multiple necking phenomenon is due to the further activation of {332} twins and SIM α“ during the necking of a certain area due to stress concentration during the stretching process, which causes local strengthening and resulting in the stop of necking. Finally, the serrations on the stress–strain curve may be caused by multiple necking.
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- 2024
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34. Multi-scale influences of as-cast microstructure heritability on intermediate/high temperature stress rupture behaviors of [111]-oriented Ni-based single crystal superalloy
- Author
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Lei Xu, Junwu Wang, Yuanhang Gao, Yi Ru, Wenyue Zhao, Jinghui Jia, Bin Gan, Shan Li, Yanling Pei, Shusuo Li, Yue Ma, and Shengkai Gong
- Subjects
As-cast microstructure heritability (CMH) ,Stress rupture property ,Deformation behavior ,Fracture mode ,Multi-scale influence ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
This study challenges the generally accepted principle that some degree of as-cast microstructure heritability (CMH), marked by -oriented dendrite-associated inhomogeneity, is tolerable in conventional [001]-oriented Ni-based single crystal (SX) superalloys. Our findings reveal that this principle does not hold for newly developed [111]-oriented SX superalloys, where -directed dendrites experience significant resolved shear stress under [111] applied loads. This work examines the stress rupture behaviors of a [111]-oriented low-Re Ni-based SX superalloy under various CMH conditions at 1100 °C/160 MPa and 760 °C/800 MPa. In the absence of CMH, the alloy achieves rupture properties comparable to fourth-generation SX superalloys. However, the presence of CMH drastically shortens rupture life and alters multi-scale deformation behaviors. High-temperature damage involves submicroscopic dislocation shearing, microscopic crack initiation, mesoscopic inter-dendritic crack connections, and macroscopic fractures. Intermediate-temperature damage is marked by submicroscopic stacking fault shearing, microscopic shear zone deformation, mesoscopic crack propagation, and macroscopic lattice rotation. Moreover, this research investigates the degradation mechanism of stress rupture property when the CMH is combined with slow cooling and reveals unique deformation behaviors, such as high-temperature subgrain formation and intermediate-temperature isolated micro-twins. This work provides new insights into the influence mechanism of the CMH.
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- 2024
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35. Deformation Behavior оf Pure Zinc Under Uniaxial Compression
- Author
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Radionova, L. V., Lisovskiy, R. A., Khlamkova, S. S., Gromov, D. V., Glebov, L. A., Chaari, Fakher, Series Editor, Gherardini, Francesco, Series Editor, Ivanov, Vitalii, Series Editor, Haddar, Mohamed, Series Editor, Cavas-Martínez, Francisco, Editorial Board Member, di Mare, Francesca, Editorial Board Member, Kwon, Young W., Editorial Board Member, Tolio, Tullio A. M., Editorial Board Member, Trojanowska, Justyna, Editorial Board Member, Schmitt, Robert, Editorial Board Member, Xu, Jinyang, Editorial Board Member, Radionov, Andrey A., editor, and Gasiyarov, Vadim R., editor
- Published
- 2024
- Full Text
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36. Operational Risks When Transporting Gas and Gas-Hydrogen Mixtures Through Existing Gas Pipelines
- Author
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Poberezhnyi, Liubomyr, Poberezhna, Liubov, Popovych, Pavlo, Kacprzyk, Janusz, Series Editor, Prentkovskis, Olegas, Series Editor, Yatskiv (Jackiva), Irina, editor, Skačkauskas, Paulius, editor, Karpenko, Mykola, editor, and Stosiak, Michał, editor
- Published
- 2024
- Full Text
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37. Study on the Micro-Scale Deformation Behavior of Al-B4C Composite by Using CPFE-CZ Model
- Author
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Tong, Xu, Li, Y., Fu, Ming Wang, Chaari, Fakher, Series Editor, Gherardini, Francesco, Series Editor, Ivanov, Vitalii, Series Editor, Haddar, Mohamed, Series Editor, Cavas-Martínez, Francisco, Editorial Board Member, di Mare, Francesca, Editorial Board Member, Kwon, Young W., Editorial Board Member, Trojanowska, Justyna, Editorial Board Member, Xu, Jinyang, Editorial Board Member, Mocellin, Katia, editor, Bouchard, Pierre-Olivier, editor, Bigot, Régis, editor, and Balan, Tudor, editor
- Published
- 2024
- Full Text
- View/download PDF
38. Effect of Friction on Corner Filling Deformation in Tube Hydroforming Process by Real-Time Measurement
- Author
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Cui, Xiao-Lei, Sun, Qianxi, Yuan, Shijian, Chaari, Fakher, Series Editor, Gherardini, Francesco, Series Editor, Ivanov, Vitalii, Series Editor, Haddar, Mohamed, Series Editor, Cavas-Martínez, Francisco, Editorial Board Member, di Mare, Francesca, Editorial Board Member, Kwon, Young W., Editorial Board Member, Trojanowska, Justyna, Editorial Board Member, Xu, Jinyang, Editorial Board Member, Mocellin, Katia, editor, Bouchard, Pierre-Olivier, editor, Bigot, Régis, editor, and Balan, Tudor, editor
- Published
- 2024
- Full Text
- View/download PDF
39. Deformation Behavior of Tool and Workpiece in Plate Compression
- Author
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Hakoyama, Tomoyuki, Jo, Kenta, Yoshikawa, Yasuharu, Wang, Zhigang, Chaari, Fakher, Series Editor, Gherardini, Francesco, Series Editor, Ivanov, Vitalii, Series Editor, Haddar, Mohamed, Series Editor, Cavas-Martínez, Francisco, Editorial Board Member, di Mare, Francesca, Editorial Board Member, Kwon, Young W., Editorial Board Member, Trojanowska, Justyna, Editorial Board Member, Xu, Jinyang, Editorial Board Member, Mocellin, Katia, editor, Bouchard, Pierre-Olivier, editor, Bigot, Régis, editor, and Balan, Tudor, editor
- Published
- 2024
- Full Text
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40. Optimization of the Hot Working Parameters and Constitutive Analysis of NiAlCrFeMo High-Entropy Alloy during Hot Forming
- Author
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Yu, Wenhan, Huo, Yuanming, Wang, Zhijun, He, Tao, Yan, Zhenrong, Ji, Hongchao, and Chen, Hao
- Published
- 2024
- Full Text
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41. Manipulation of microstructure evolution and deformation behavior in Ni–Mn–Ga shape memory alloys with varied Ni/Ga under uniaxial cyclic compression
- Author
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Wang, Xin-Xiu, Ding, Xin, Chen, Rui-Run, Ding, Jie-Fei, Shen, Hong-Xian, Qian, Ming-Fang, Zhang, Yong, and Wu, Shi-Ping
- Published
- 2024
- Full Text
- View/download PDF
42. Health diagnosis of ultrahigh arch dam performance using heterogeneous spatial panel vector model
- Author
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Er-feng Zhao, Xin Li, and Chong-shi Gu
- Subjects
Ultrahigh arch dam ,Structural performance ,Deformation behavior ,Diagnosis criterion ,Panel data model ,River, lake, and water-supply engineering (General) ,TC401-506 - Abstract
Currently, more than ten ultrahigh arch dams have been constructed or are being constructed in China. Safety control is essential to long-term operation of these dams. This study employed the flexibility coefficient and plastic complementary energy norm to assess the structural safety of arch dams. A comprehensive analysis was conducted, focusing on differences among conventional methods in characterizing the structural behavior of the Xiaowan arch dam in China. Subsequently, the spatiotemporal characteristics of the measured performance of the Xiaowan dam were explored, including periodicity, convergence, and time-effect characteristics. These findings revealed the governing mechanism of main factors. Furthermore, a heterogeneous spatial panel vector model was developed, considering both common factors and specific factors affecting the safety and performance of arch dams. This model aims to comprehensively illustrate spatial heterogeneity between the entire structure and local regions, introducing a specific effect quantity to characterize local deformation differences. Ultimately, the proposed model was applied to the Xiaowan arch dam, accurately quantifying the spatiotemporal heterogeneity of dam performance. Additionally, the spatiotemporal distribution characteristics of environmental load effects on different parts of the dam were reasonably interpreted. Validation of the model prediction enhances its credibility, leading to the formulation of health diagnosis criteria for future long-term operation of the Xiaowan dam. The findings not only enhance the predictive ability and timely control of ultrahigh arch dams’ performance but also provide a crucial basis for assessing the effectiveness of engineering treatment measures.
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- 2024
- Full Text
- View/download PDF
43. Lightweight design of lattice structure of boron steel prepared by selective laser melting
- Author
-
Qi Zheng, Hong sheng Chen, Jun Zhou, Wen xian Wang, Liu wei Zheng, and San xiao Xi
- Subjects
Selective laser melting (SLM) ,Triply periodic minimal surfaces (TPMS ,Energy absorption ,Surface morphology ,Deformation behavior ,Mining engineering. Metallurgy ,TN1-997 - Abstract
Three-cycle minimum surface structures show excellent lightweight and energy absorption capabilities, and additive manufacturing techniques provide a unique degree of freedom for lattice structure design. Therefore, in this study, three-period minimum surface (TPMS) structures of Schwarz-P boron steel alloys were prepared by Selective Laser Melting (SLM) technique. By investigating the effect of lattice structure design, we have analyzed the deformation behavior, mechanical properties and energy absorption capacity under compression. In addition, tensile properties and fracture morphology were analyzed to gain insight into the performance characteristics of these structures, and the effect of structural design on hardness was explored. The results of the study show that the structural design has a small effect on the microstructure and hardness. Under compressive loading, the P (0.5 1) structure exhibits a uniform deformation behavior, while the other four structures show a crushing deformation pattern. In particular, the P (0.5 1) structure exhibits excellent compressive performance, with an energy absorption work per unit mass as high as 296.2 J/mm^3, and its stiffness reaches 1627 MPa. Meanwhile, the P (0.35 1) structure exhibits excellent tensile performance with the tensile strength of 687 MPa. The morphological analysis of the tensile fracture reveals that the fracture mainly occurs in the strut nodes, and it mainly exhibits ductile tensile fracture.
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- 2024
- Full Text
- View/download PDF
44. Understanding the role of interface in deformation behavior of additively manufactured bimetallic structures of pure metals
- Author
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Ali Afrouzian and Amit Bandyopadhyay
- Subjects
Bimetallic structures ,Deformation behavior ,Additive manufacturing ,Nickel ,Titanium ,Tantalum ,Mining engineering. Metallurgy ,TN1-997 - Abstract
Directed energy deposition (DED)-based additive manufacturing (AM) was employed to fabricate three distinct bimetallic compositions to understand the role interface for the deformation behavior of bimetallic structures under compressive loading. Commercially pure titanium (CP Ti) with a hexagonal closed packed (HCP) structure, nickel (Ni) with a face-centered cubic (FCC), and tantalum (Ta) with a body-centered cubic (BCC) structure were selected to understand the deformation behavior within the pure metals and damage accumulation at the bimetallic interface. By incorporating the combination of these materials, such as Ni–Ti, Ni–Ta, and Ta–Ti, we aimed to manufacture layered-base polycrystalline composite structures with FCC-HCP, FCC-BCC, and BCC-HCP crystal unit cells, respectively. In Ni–Ti and Ni–Ta bimetallic structures, it was determined that deformation is controlled by the Ni region, where the highest deflection occurs when Ni bulges out and makes lateral stress at the interface, resulting in crack initiation, propagation, and failure of the structure. Structural edges were found to experience the highest deformation, prompting grain inclination towards the crystal orientation, resulting in a favorable orientation for dislocation slip and a higher Taylor factor. However, strong interfacial bonding and similar Young's modulus between Ta and Ti altered the deformation mechanisms to twinning formation in the Ti region and observed buckling of the entire structure without significant failure at the interface.
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- 2024
- Full Text
- View/download PDF
45. Improving forming accuracy of variable-diameter tube by electromagnetic forming using segmented coil.
- Author
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Li, Changxing, Xu, Xiaofei, Ouyang, Shaowei, Du, Limeng, Zhang, Wang, Zhu, Xinhui, Han, Xiaotao, Cao, Quanliang, and Li, Liang
- Subjects
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LORENTZ force , *TUBE manufacturing , *TUBES , *SOLENOIDS , *MANUFACTURING industries - Abstract
Electromagnetic forming (EMF) has shown considerable promise in lightweight alloy tube manufacturing industry. However, the generated force field falls short of meeting the stringent forming accuracy requirements for variable-diameter tubes. To solve this, this paper proposes an EMF process using a novel coil structure, named as segmented coil, to improve the forming quality of tubes. The design and implementation of coil, as well as the deformation behavior of tubes, are discussed. Results show that a multi-layer solenoid coil can generate excessive force on the upper portion of the tube, thus causing an undesired gap between the coil and tube that is unfavorable for forming performance. In contrast, when employing a segmented coil, the force applied to this section is mitigated, allowing the tube to fit into the die from bottom to top and achieving a maximum die-fitting gap of no more than 0.1 mm. Besides, it is found that the forming accuracy increases with increasing discharge energy, and an optimal coil structure exists when the discharge energy is fixed. This work showcases the considerable flexibility of the segmented coil in controlling the Lorentz force distribution and tube deformation behavior. These findings hold significant implications for expanding the applications of EMF technology. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
46. Deformation behavior and mechanical anisotropy in ZrB2-based ceramic.
- Author
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Wei, Zhifan, Zu, Yufei, He, Zhubin, Lin, Yanli, Fu, Xuesong, Zhou, Wenlong, and Chen, Guoqing
- Subjects
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DEFORMATIONS (Mechanics) , *ANISOTROPY , *STRAIN rate , *FRACTURE toughness , *MICROSTRUCTURE , *CERAMICS - Abstract
The deformation behavior and mechanical properties of ZBHO x ceramic (ZrB 2 based ceramics with different amounts of (HfO 2 + 2 vol% CaO), x = 10 - 25 vol%) have been investigated. The results demonstrated that the flow stress of ZBHO x ceramic decreased with an increase in the (HfO 2 +2 vol% CaO) addition at the same strain rate. The flow stress decreased from ∼178 MPa for ZBHO 10 to ∼13 MPa for ZBHO 20 at 1700 °C and a strain rate of 2 × 10−4 s−1, representing a reduction of an order of magnitude. The intergranular deformation twinning and the amorphous phase contribute to the grain boundary sliding and grain rotation of the boride matrix grains, resulting in a significant reduction in flow stress. The matrix grains orientations on the P face (the face perpendicular to the extrusion direction) primarily tend to be along the {0001} plane, while that on the V face (the face parallel to the extrusion direction) tend to be along the {-12-10} plane or {01–10} plane. The textured ZBHO x ceramics exhibit distinct mechanical anisotropy because of the significant orientation difference in the microstructure. The hardness of textured ZBHO x ceramics on V face is higher than that on P face. And the fracture toughness of ZBHOx ceramics exhibits anisotropy on the V face, the fracture toughness in the V-o direction (the direction perpendicular to the P face) is higher than that in V-p direction (the direction parallel to the P face) of ZBHO x ceramics. The intergranular oxide twins synergistically collaborate with the grain rotation within the boride matrix, fostering favorable conditions for texture development. Besides that, the amorphous phase at the interface, characterized by a substantial presence of vacancies and defects, functions as a source of vacancies that facilitates diffusion deformation along the grain boundaries. Simultaneously, the emergence of an amorphous phase at grain boundaries or triple grain junctions further enhances grain boundary sliding and grain rotation of ZrB 2 and B 4 ZrHf grains. [Display omitted] • Mechanically anisotropic textured ZrB 2 ceramics were successfully prepared through the sintering-forging method. • By controlling the content of (HfO 2 +2 vol% CaO), the flow stress of ZrB 2 can be reduced by an order of magnitude. • The formation of oxide twins and amorphous phase facilitate grain boundary sliding and grain rotation of ZrB 2 grains. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
47. Towards understanding the influence of structured indenters geometry on material deformation behavior of indentation process.
- Author
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Lou, Zaizhen, Zheng, Xiaogang, Yan, Yongda, Wang, Han, Zhang, Aoxiang, Zhao, Donghua, Yang, Yanting, Cui, Hailong, and Geng, Yanquan
- Subjects
- *
SPRINGBACK (Elasticity) , *DISLOCATION nucleation , *MATERIAL plasticity , *NANOINDENTATION , *DEFORMATIONS (Mechanics) , *MOLECULAR dynamics - Abstract
Nanoindentation has emerged as a pioneering technique for fabricating array structures at the nanoscale. This research incorporates molecular dynamics simulations to investigate the deformation mechanisms of materials influenced by structured indenters exhibiting diverse geometries. The primary objective of this study is to mitigate interference during the continuous indentation applied by the indenters, diminish the material's elastic recovery, and minimize the occurrence of defects. The simulation results unveil that plastic deformation of the workpiece induced by structured indenters manifests through the nucleation and slip of dislocations. The cylindrical indenter engenders the most pronounced residual indentation morphology, accompanied by substantial pile-up interference and an extensive range of dislocation expansion, surpassing that of other indenters. Conversely, pyramidal indenters exhibit minimal residual indentation morphology, albeit displaying considerable elastic recovery. A comprehensive evaluation that considers factors such as recovery after indentation, ease of processing, system stability, and material transfer against the indentation force is imperative for the determination of the ideally structured indenter. The meticulous analysis supports the efficacy of paraboloidal indenters possessing smaller taper angles in attaining consistent processing results, rendering them highly suitable for continuous indentation processing. The research content bears significant implications for advancing the application of structured indenters. [Display omitted] • The defect evolution mechanisms of the structured indentation processing were analyzed. • The plastic deformation mechanisms of structured indenters processing were analyzed. • The filling rates of characteristic gaps were presented and calculated for structured indenters. • The indentation recovery rate and stability of the structured indenter were calculated and analyzed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. In Situ Study of Precipitates' Effect on Grain Deformation Behavior and Mechanical Properties of S31254 Super Austenitic Stainless Steel.
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Ma, Jinyao, Tan, Huanyu, Dong, Nan, Gao, Jiemin, Wang, Puli, Wang, Zhihua, and Han, Peide
- Subjects
- *
AUSTENITIC stainless steel , *DEFORMATIONS (Mechanics) , *DETERIORATION of materials , *MATERIAL plasticity , *HEAT treatment , *STAINLESS steel - Abstract
Grain boundary (GB) precipitation-induced cracking is a significant issue for S31254 super austenitic stainless steel during hot working. Investigating the deformation behavior based on precipitate morphology and distribution is essential. In this study, continuous smaller and intermittent larger precipitates were obtained through heat treatments at 950 °C and 1050 °C. The microstructure evolution and mechanical properties influenced by precipitates were experimentally investigated using an in situ tensile stage inside a scanning electron microscope (SEM) combined with electron backscatter diffraction (EBSD). The results showed that continuous precipitates at 950 °C had a stronger pinning effect on the GB, making grain rotation difficult and promoting slip deformation in the plastic interval. Continuous precipitates caused severe stress concentration near GB and reduced coordinated deformation ability. Additionally, the crack propagation path changed from transcrystalline to intercrystalline. Furthermore, internal precipitates were a crucial factor affecting the initial crack nucleation position. Interconnected precipitates led to an intergranular fracture tendency and severe deterioration of the material's plasticity, as observed in fracture morphology. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. Effect of Strain Rate on Mechanical Deformation Behavior in CuZr Metallic Glass.
- Author
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Fan, Beibei and Li, Maozhi
- Subjects
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STRAIN rate , *DEFORMATIONS (Mechanics) , *STRAINS & stresses (Mechanics) , *ATOMIC clusters , *MOLECULAR dynamics , *METALLIC glasses - Abstract
Tensile tests were performed on Cu64Zr36 metallic glass at strain rates of 107/s, 108/s, and 109/s via classical molecular dynamics simulations to explore the underlying mechanism by which strain rate affects deformation behavior. It was found that strain rate has a great impact on the deformation behavior of metallic glass. The higher the strain rate is, the larger the yield strength. We also found that the strain rate changes the atomic structure evolution during deformation, but that the difference in the atomic structure evolution induced by different strain rates is not significant. However, the mechanical response under deformation conditions is found to be significantly different with the change in strain rate. The average von Mises strain of a system in the case of 107/s is much larger than that of 109/s. In contrast, more atoms tend to participate in deformation with increasing strain rate, indicating that the strain localization degree is more significant in cases of lower strain rates. Therefore, increasing the strain rate reduces the degree of deformation heterogeneity, leading to an increase in yield strength. Further analysis shows that the structural features of atomic clusters faded out during deformation as the strain rate increased, benefiting more homogeneous deformation behavior. Our findings provide more useful insights into the deformation mechanisms of metallic glass. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. Effect of Structural-Phase State on the Deformation Behavior and Mechanical Properties of Near β Titanium Alloy VT22 in the Temperature Range 293–823 K.
- Author
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Grabovetskaya, G. P., Mishin, I. P., Naydenkin, E. V., Ratochka, I. V., Stepanova, E. N., Zabudchenko, O. V., and Lykova, O. N.
- Abstract
This paper investigates the effect of thermomechanical treatments, including deformation by radial shear rolling or severe plastic deformation by abc pressing with subsequent aging at 773 K, on the structural-phase state, deformation behavior, and mechanical properties of commercial near β titanium alloy VT22 (Ti–5Al–5Mo–5V–1Cr–1Fe). The structure of the alloy after radial shear rolling and subsequent aging consists of transformed β grains with a lamellar α + β structure and primary α-phase particles. Severe plastic deformation of the alloy followed by aging causes the formation of a grain-subgrain α + β structure with an average characteristic size of 0.23 µm. It is found that, after the thermomechanical treatments, the strength characteristics of the alloy at room temperature increase by ~40% compared to the as-received alloy. The alloy after radial shear rolling and aging retains a 40–20% higher strength in the temperature range of 293–823 K. The strength of the alloy after severe plastic deformation and aging becomes lower than that of the as-received alloy already at a temperature of 773 K. Analysis of creep parameters at 743 K shows that the creep deformation of the alloy in the state after radial shear rolling and aging occurs by the motion of dislocations (glide + climb). The creep deformation of the alloy in the state after severe plastic deformation and subsequent aging is largely contributed by grain boundary sliding. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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