1,777 results on '"Hot press"'
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2. Microstructure and mechanical properties of Ti6Al4V-(TiC+TiB)/Ti laminated composites fabricated by hot press plus hot rolling
- Author
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Zhang, Jiachen, Yang, Mingnian, Zhao, Xin, Chen, Shuoyan, Tao, Dong, Yan, Hanyang, Huang, Shixing, and Yang, Zhong
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- 2025
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3. Hot-press sintering of SiC whisker reinforced TiB2-B4C composites and its mechanical property characterizations
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Yu, Lei, Zhang, Kuibao, Chen, Daimeng, and Luo, Baozhu
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- 2024
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4. Effect of Si Gradient Pattern on the Microstructure and Properties of Laminated Electrical Steel Composites Prepared by Hot-Press Sintering
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Ke Gao, Qiang Xu, Haitao Jiao, and Yong Hu
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Si gradient electrical steel composites ,hot-press sintering ,microstructure ,magnetic properties ,mechanical properties ,Crystallography ,QD901-999 - Abstract
In this study, electrical steel laminated composites with positive Si gradient (PO-G), counter Si gradient (CO-G), and cross Si gradient (CR-G) were fabricated by hot-press sintering, cold rolling and annealing. The microstructure evolution during processing, as well as the magnetic and mechanical properties were investigated. The results indicate that the microstructure of the high-silicon layer and medium-silicon layer in the hot-pressed composites featured columnar grains throughout the thickness. The microstructure of the low-silicon layer in the hot-pressed CO-G sample consisted of equiaxed grains. However, a mixed structure dominated by columnar grains with some equiaxed grains was observed in the inner low-silicon layer of the PO-G and CR-G samples. Following cold rolling, the thickness ratio of each layer remained largely unchanged. After annealing, the microstructure of each layer transformed into columnar grains. The average grain size of the high-silicon layer, medium-silicon layer, and low-silicon layers in the three composites were approximately 20–23 μm, 33–38 μm, and 42–49 μm, respectively. Compared with the CO-G and CR-G samples, the annealed PO-G composite exhibited lower core loss at 400–1000 Hz and superior tensile strength. Furthermore, the core loss of the three composites was greater than that of the initial medium-silicon and high-silicon materials. This can be attributed to the increased hysteresis loss due to the existence of multi-layer interface.
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- 2024
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5. Characterization of (Zr,Ti)B2-SiC composites obtained by hot press sintering of ZrB2-SiC-TiO2 powder mixtures
- Author
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Rosa Maria da Rocha, Francisco Cristovão Lourenço de Melo, Frank Ferrer Sene, João Marcos Kruszynski de Assis, and Miriam Kasumi Hwang Yassuda
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Hot pressing ,ZrB2-SiC ,Ultra-high temperature ceramics ,Microstructure ,Mechanical properties ,Solid solution ,Clay industries. Ceramics. Glass ,TP785-869 - Abstract
The ability to enhance mechanical and oxidation properties for severe environmental applications has led to substantial academic interest in multiphase ultra-high temperature ceramics (UHTC). The purpose of this work is to study the in-situ solid solution formation of (Zr,Ti)B2 from ZrB2 and TiO2 in a ZrB2-SiC composite using hot pressing reaction sintering. For this, a mixture of 10, 20, and 30 % vol% SiC with ZrB2 was mixed with 2.0 wt% TiO2. Hot pressing sintering was performed with a load of 20 MPa at a final temperature of 1850 °C/30 min in an argon atmosphere. The microstructures, crystalline phases, densities, mechanical properties, and oxidation resistance of the composites were examined and compared with ZrB2-SiC samples lacking TiO2. In samples where TiO2 was added, the matrix grain size slightly decreased, the fracture mode was mainly intergranular, and the SiC grain morphology changed the aspect ratio to be more equiaxed. The solid solution (Zr,Ti)B2 was produced, and it was demonstrated by EDS elemental map images and the XRD analysis that Ti atoms incorporate into the ZrB2 crystalline structure. The development of solid solutions showed no impact on relative densities or Vickers hardness. However, the solid solution formation favored an improvement in fracture toughness, probably owing to the smaller matrix grain size and intergranular fracture mode. Samples exhibiting (Zr,Ti)B2 formation presented lower oxidation resistance than undoped samples in the same oxidizing condition.
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- 2024
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6. Microstructure and mechanical properties of laser welded hot-press-formed steel with varying thicknesses of Al–Si coatings cleaned by nanosecond pulsed laser
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Xi Chen, Shengkui Zhang, Meng Jiang, Yuan Chen, Yumo Jiang, Zhiyuan Wang, Nan Jiang, Ao Chen, Bingwei Li, Zhenglong Lei, and Yanbin Chen
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Al–Si coating ,Hot-press-forming steel ,Laser cleaning ,Laser welding ,Microstructure ,Mechanical properties ,Mining engineering. Metallurgy ,TN1-997 - Abstract
The Al–Si coatings are commonly used for hot-press-forming (HPF) steel to prevent oxidation in the automobile industry. However, due to the presence of Al–Si coating, undesirable intermetallic compounds are easily formed in the welds of HPF steel. In this work, an environment-friendly and effective nanosecond pulsed laser cleaning process was used to remove the Al–Si coating, and HPF steel with varying thicknesses of coatings was prepared for laser welding. The microstructure and mechanical properties of laser welded HPF steel with different thicknesses of coatings were further investigated. The results showed that there was a threshold of power to remove the Al–Si coatings in the laser cleaning process. The reduced thickness of coatings not only could improve the stability of the welding process due to the diminishing of metal vapor generated by coating ablation, but also decrease the content of the Fe–Al phase in the welded joint, which is detrimental to weld performance. The tensile strength and cupping test pass rate of weld joints gradually increased with the decreasing thickness of coatings to 5 μm. After that, the Al–Si coating almost had no effect on the mechanical properties of the laser weld joints. The laser weld joint with 5 μm-thick of Al–Si coating showed, a tensile strength of 1435.05 MPa, a microhardness of 488.38 HV and a pass rate of 100% for the cupping test.
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- 2023
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7. Enhancing the microstructure and mechanical properties of CrCoFeNiAl high-entropy alloy produced by hot press sintering through laser remelting
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Xi Wang, Haodong Tian, Yuzhen Yu, Shuangyu Liu, He Liu, Ben Wang, and Hanpeng Gao
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High entropy alloy(HEA) ,Laser remelting ,Mechanical properties ,Microstructure ,Microhardness ,Mining engineering. Metallurgy ,TN1-997 - Abstract
Herein, laser remelting (LR) and hot press sintering (HPS) were combined to process high-entropy alloy (HEA) and strengthen desirable microstructure. The microstructural changes of HEA before and after LR processing were experimentally investigated. In Scanning Electron Microscope (SEM) and electron backscatter diffraction (EBSD) observations, it was found that the microstructure of the remelting zone was mainly composed of dendritic isometric crystals, and the laser remelting technique can refine the grain structure of HEA. The combined strengthening features of dislocations and twinning were observed by Transmission electron microscopy (TEM), and the phase structure of the grains was analyzed in conjunction with the X-ray diffraction(XRD) analysis, confirming the presence of B2 with BCC solid-solution and FCC phase. Finally, micron-sized scratches, tensile experiments and microhardness experiments were performed, and it was found that the Mechanical properties of the remelting zone were significantly enhanced. It was demonstrated that the strengthening of HEA, sintered by LR and HPS techniques, is due to the synergistic influence of various strengthening mechanisms, such as fine grain strengthening, dislocation strengthening, solid-solution strengthening and twinning strengthening.
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- 2024
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8. Application of the Hot Press Method to Produce New Mg Alloys: Characterization, Mechanical Properties, and Effect of Al Addition
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Ercetin, Ali
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- 2021
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9. Evaluation on the microstructure and corrosion properties of in situ prepared FeCrNiCo-boride cermet by hot press sintering.
- Author
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Zhang, Shitao, Zhao, Yuantao, Li, Wenge, Liu, Minghui, Jiang, Chunxia, Pan, Zhengyang, Sun, Boyang, Chen, Peng, and Liu, Yanbo
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OPEN-circuit voltage , *GIBBS' free energy , *HOT pressing , *CERAMIC metals , *CRYSTAL lattices - Abstract
Traditional studies on boride cermet have rarely considered the effects of the synergistic interactions among their multiple components on their microstructure and properties. In this study, FeCrNiCo-boride cermet is prepared for the first time via hot-press sintering. The microstructure evolution and corrosion resistance of the cermet are investigated for sintering temperatures in the range of 1000–1300 °C. The results show that the phase comprises Mo 2 FeB 2 , MoB 2 , and FCC phases (including that of FeCrNiCo or various intermetallic solid solutions formed by FeCrNiCo decomposition). Owing to its low Gibbs free energy, Mo 2 FeB 2 occurs in the hard phase. Cr atoms dissolve into the crystal lattice and stabilise the Mo 2 FeB 2 crystals. A certain amount of MoB 2 is also present in the hard phase. The bond phase is formed by alloying elements and solid solutions. The cermet sintered at 1100 °C exhibits the least structural defects, highest cermet content, and best corrosion resistance; the porosity is 9.94 % and phase ratio of cermet is 48.9 %. The cermet phase has the smallest grain size of 5.96 μm. The equilibrium potential (E corr) is −0.52 V, corrosion current density (I corr) is 2.07 × 10−6 A/cm2, and open-circuit potential (OCP) in a 3.5 % NaCl solution is −0.34 V. [ABSTRACT FROM AUTHOR]
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- 2024
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10. Microstructure and bond strength of niobium carbide coating on GCr15 prepared by in-situ hot press sintering
- Author
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Jilin Li, Haiqiang Bai, Ruixue Li, Yao Zhu, Le Chen, Nana Zhao, and Yunhua Xu
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Niobium carbide coating ,Bearing steel ,In-situ reaction ,Microstructure ,Bond strength ,Mining engineering. Metallurgy ,TN1-997 - Abstract
The hardness and adhesion of protective hard coatings to the substrate are the most important parameters that influence the performance of the tool. Herein, we propose an effective strategy, by in-situ hot press sintering, to fabricate a novel niobium carbide coating with high hardness and excellent interfacial bond strength on GCr15. The coating is composed of Nb2C, NbC, and α-Fe phases. The volume fraction of niobium carbide (Nb2C and NbC) phases reaches 93%. Along the direction of coating thickness, the grain morphology of niobium carbide changes from equiaxed (Nb2C) to columnar (NbC), and then to equiaxed (NbC), presenting a gradient microstructure. The coating/substrate interface displays an excellent macro/micro interface. The formation of the gradient microstructure is attributed to the nucleation-growth process controlled by the carbon concentration gradient diffusion. The novel gradient coating can simultaneously achieve superhardness (20.2 ± 0.3 GPa) and excellent bond strength (>210 ± 20 MPa). The excellent bond strength is mainly attributed to the in-situ formation of the coating and the gradient microstructures. The tensile test results show that the fracture mechanism of the niobium carbide coating on GCr15 is mainly a brittle fracture of niobium carbide coating and a small amount of coating debonding.
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- 2023
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11. Microstructure and Properties of Mn-Cu-Based Damping Alloys Prepared by Ball Milling and Hot-Press Sintering
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Zhang, Song, Guo, Xi-Ping, Tang, Ye, You, Wei-Xing, and Xu, Yong-Gang
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- 2019
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12. Improving the Fracture Toughness of Boron Carbide via Minor Additions of SiC and TiB 2 Through Hot-Press Sintering.
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Ka, Juhan, Kim, Kyoung Hun, Choi, Woohyuk, Jung, Sungmo, Lee, Tae Hwan, Kim, Hyun Sik, Lee, Heesoo, and Lee, Jae Hwa
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CRACK propagation , *FRACTURE toughness , *GRAIN size , *HOT pressing , *FRACTURE strength , *BORON carbides - Abstract
Boron carbide (B4C) is an essential material in various high-performance applications due to its light weight and hardness. In this work, B4C-based composites were fabricated via a powder route consisting of powder mixing, precursor preparation, and hot-pressing under vacuum. The composites' mechanical properties and microstructure were analyzed to investigate the effect of adding minor second-phase particles. In addition to homogenizing the grain size, the addition of SiC (≤10 wt%) to B4C increased its strength and improved its fracture toughness, with values reaching 551 MPa and 3.22 MPa m1/2, respectively. Meanwhile, the addition of TiB2 (≤10 wt%) significantly improved the strength and fracture toughness only, with values reaching 548 MPa and 3.92 MPa m1/2, respectively, with only a minimal decrease in hardness. Microstructural analysis revealed that the second-phase particles were uniformly distributed and reduced the average grain size, contributing to the increase in strength. Additionally, the TiB2 particles impeded crack propagation and induced crack deflection at the interface, indicating the formation of an intergranular fracture mode. On the contrary, the addition of SiC primarily resulted in transgranular fracture behavior, though it still improved the toughness of the B4C. These results suggest that small amounts of SiC and TiB2 can effectively enhance the mechanical properties of B4C ceramics while maintaining the lightweight characteristics critical for military and aerospace applications. [ABSTRACT FROM AUTHOR]
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- 2024
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13. Fabrication of FeCu Matrixed Diamond Tool Bits Using Microwave Hot-Press Sintering
- Author
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Hou, Ming, Wang, Liang, Guo, Shenghui, Yang, Li, Gao, Jiyun, Hu, Tu, and Ye, Xiaolei
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- 2019
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14. Microstructure, Mechanical Properties and Oxidation Resistance of Nb-Si Based Ultrahigh-Temperature Alloys Prepared by Hot Press Sintering.
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Zhang, Lijing, Guan, Ping, and Guo, Xiping
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HOT pressing , *MICROSTRUCTURE , *VICKERS hardness , *OXIDE coating , *FRACTURE toughness , *SILICON alloys - Abstract
Nb-Si based ultrahigh-temperature alloys with the composition of Nb-22Ti-15Si-5Cr-3Al (atomic percentage, at. %) were prepared by hot press sintering (HPS) at 1250, 1350, 1400, 1450 and 1500 °C. The effects of HPS temperatures on the microstructure, room temperature fracture toughness, hardness and isothermal oxidation behavior of the alloys were investigated. The results showed that the microstructures of the alloys prepared by HPS at different temperatures were composed of Nbss, βTiss and γ(Nb,X)5Si3 phases. When the HPS temperature was 1450 °C, the microstructure was fine and nearly equiaxed. When the HPS temperature was lower than 1450 °C, the supersaturated Nbss with insufficient diffusion reaction still existed. When the HPS temperature exceeded 1450 °C, the microstructure coarsened obviously. Both the room temperature fracture toughness and Vickers hardness of the alloys prepared by HPS at 1450 °C were the highest. The alloy prepared by HPS at 1450 °C exhibited the lowest mass gain upon oxidation at 1250 °C for 20 h. The oxide film was mainly composed of Nb2O5, TiNb2O7, TiO2 and a small amount of amorphous silicate. The formation mechanism of oxide film is concluded as follows: TiO2 forms by the preferential reaction of βTiss and O in the alloy; after that, a stable oxide film composed of TiO2 and Nb2O5 forms; then, TiNb2O7 is formed by the reaction of TiO2 and Nb2O5. [ABSTRACT FROM AUTHOR]
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- 2023
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15. Effect of Fe on the Microstructure and Mechanical Properties of Fe/FeAl2O4 Cermet Prepared by Hot Press Sintering
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Kuai Zhang, Yungang Li, Chuang Wang, Hongyan Yan, Hui Li, Jinglong Liang, and Jie Dang
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Fe phase ,Fe/FeAl2O4 cermet ,hot press sintering ,microstructure ,mechanical properties ,Crystallography ,QD901-999 - Abstract
The Fe/FeAl2O4 cermet was prepared with Fe-Fe2O3-Al2O3 powder by a hot press sintering method at 1400 °C. The raw materials for the powder particles were respectively 2 µm (Fe), 0.5 µm (Fe2O3), and 0.5 µm (Al2O3) in diameter, the sintering pressure was 30 MPa, and the holding time was 120 min. The effects of different Fe mass ratios on the microstructure and mechanical properties of Fe/FeAl2O4 cermet were studied. The results showed that a new ceramic phase FeAl2O4 could be formed by an in situ reaction during the hot press sintering. When the Fe mass ratio was increased, the microstructure and mechanical properties of the Fe/FeAl2O4 cermet showed a change law that initially became better and then became worse. The best microstructure and mechanical properties were obtained in the S2 sample, where the mass ratio of Fe-Fe2O3-Al2O3 was 6:1:2. In this Fe mass ratio, the relative density was about 94%, and the Vickers hardness and bending strength were 1.21 GPa and 210.0 MPa, respectively. The reaction mechanism of Fe in the preparation process was the in situ synthesis reaction of FeAl2O4 and the diffusion reaction of Fe to FeAl2O4 grains. The increase of the Fe mass ratio improved the wettability of Fe and FeAl2O4, which increased the diffusion rate of Fe to FeAl2O4 grains, which increased the influence on the structure of FeAl2O4.
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- 2021
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16. Influence of Extrusion Temperature on Properties of Graphene Oxide-Carbon Fiber/Epoxy Composite Prepared by Vacuum Infiltration Hot-Press-Forming Experimental System
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Yuqin Ma, Fei Li, Wei Xu, Yuyang Zhang, Yi Xu, Haiyin Guo, and Yatao Li
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VIHPS ,graphene oxide ,carbon fiber composites ,extrusion temperature ,microstructure ,bending properties ,Chemistry ,QD1-999 - Abstract
Graphene oxide-carbon fiber/epoxy (GO-CF/EP) composites with extrusion temperatures of 30, 40, 50, 60 and 70 °C were prepared by a vacuum infiltration hot-press-forming experimental system (VIHPS). The effects of extrusion temperature on the microstructure, fracture mechanism and mechanical properties of GO-CF/EP composites were investigated. It was found that the best mechanical property of composites and infiltration effect of the matrix in the fiber gap were obtained at the temperature of 50 °C, and the bending strength of the composite reached 728 MPa. The fiber was pulled out and broken under the wrapping of the matrix. The matrix viscosity was high, and the fluidity was poor when the extrusion temperature was low. The poor infiltration of the matrix resulted in many fibers failing to bond together, resulting in the disorderly breakage of fiber bundles. Under the condition of higher temperature, the flow speed of the matrix could be improved. However, part of the matrix was extruded during the extrusion process, and cracks and other defects occurred during the loading, which caused the brittle fracture of the specimen.
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- 2022
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17. Interpretation of surficial shear crack propagation mechanisms in bending for Zn or AlSi coated hot press forming steels
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Jin-Keun Oh, Seok Su Sohn, Sang-Heon Kim, Selim Kim, Min Cheol Jo, Sunghak Lee, and Seongwoo Kim
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Total internal reflection ,Multidisciplinary ,Materials science ,020502 materials ,Science ,0211 other engineering and technologies ,Fracture mechanics ,Mechanical properties ,02 engineering and technology ,Bending ,Metals and alloys ,engineering.material ,Microstructure ,Article ,Hot press ,Shear (sheet metal) ,Cracking ,0205 materials engineering ,Coating ,engineering ,Medicine ,Composite material ,021102 mining & metallurgy - Abstract
The bending angle at the peak load is regarded as the most important parameter for evaluating bending properties of hot-press-forming (HPF) steels. However, it is not a mechanics-based parameter for the bending criterion, and the data interpretation is difficult because bending criteria in relation with microstructures and associated bending mechanisms have not been verified yet. In this study, effects of coating and baking treatments on bending angles at the peak load of three kinds of 1470 MPa-grade HPF steels were investigated by interrupted three-point bending tests coupled with direct microstructural observation. According to direct observations of sequential cracking processes of V-shaped crack (V-crack), bending procedures were classified into four stages: (1) formation of small V-crack, (2) increase in number and size of V-cracks, (3) initiation of shear-crack propagation from the V-crack tip, and (4) further propagation and opening of the shear crack. The minimum bending angle required for initiating the shear-crack propagation from the V-crack tip was defined as a critical angle, which meant the boundary between the 2nd and 3rd stages. The present bending behavior related with critical bending angle and V-cracking could be interpreted similarly by the fracture-mechanics concept, i.e., the initiation of shear-crack propagation.
- Published
- 2021
18. Microstructures and mechanical properties of Ti-45Al-10Nb alloy produced by ball milling and hot press consolidation
- Author
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Wei Boxin, Xue Wen Li, Feng Li, Peihao Ye, and Fang Wenbin
- Subjects
Materials science ,Consolidation (soil) ,Alloy ,Metallurgy ,Sintering ,engineering.material ,Condensed Matter Physics ,Hot pressing ,Microstructure ,Electronic, Optical and Magnetic Materials ,Hot press ,Powder metallurgy ,engineering ,Ball mill - Abstract
The microstructures and properties of powder metallurgy Ti-45Al-10Nb (at.%) alloys fabricated by vacuum hot pressing consolidation of milled powder have been investigated. Under the sintering condi...
- Published
- 2021
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19. Fabrication of In Situ TiBCSi Composite by Hot-Press Sintering
- Author
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Xiao, D. H., Li, X. X., Wu, Z. S., Liu, D., Yuan, T. C., and Song, M.
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- 2013
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20. Effect of Si Gradient Pattern on the Microstructure and Properties of Laminated Electrical Steel Composites Prepared by Hot-Press Sintering.
- Author
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Gao, Ke, Xu, Qiang, Jiao, Haitao, and Hu, Yong
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COLD rolling ,MAGNETIC traps ,GRAIN size ,LAMINATED materials ,MAGNETIC properties ,ELECTRICAL steel - Abstract
In this study, electrical steel laminated composites with positive Si gradient (PO-G), counter Si gradient (CO-G), and cross Si gradient (CR-G) were fabricated by hot-press sintering, cold rolling and annealing. The microstructure evolution during processing, as well as the magnetic and mechanical properties were investigated. The results indicate that the microstructure of the high-silicon layer and medium-silicon layer in the hot-pressed composites featured columnar grains throughout the thickness. The microstructure of the low-silicon layer in the hot-pressed CO-G sample consisted of equiaxed grains. However, a mixed structure dominated by columnar grains with some equiaxed grains was observed in the inner low-silicon layer of the PO-G and CR-G samples. Following cold rolling, the thickness ratio of each layer remained largely unchanged. After annealing, the microstructure of each layer transformed into columnar grains. The average grain size of the high-silicon layer, medium-silicon layer, and low-silicon layers in the three composites were approximately 20–23 μm, 33–38 μm, and 42–49 μm, respectively. Compared with the CO-G and CR-G samples, the annealed PO-G composite exhibited lower core loss at 400–1000 Hz and superior tensile strength. Furthermore, the core loss of the three composites was greater than that of the initial medium-silicon and high-silicon materials. This can be attributed to the increased hysteresis loss due to the existence of multi-layer interface. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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21. Study on Hot Press Forming Process of Large Curvilinear Generatrix Workpiece of Ti55 High-Temperature Titanium Alloy
- Author
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Fengyong Wu, Wenchen Xu, Zhongze Yang, Bin Guo, and Debin Shan
- Subjects
Ti55 alloy ,hot press forming ,hot deformation ,microstructure ,Mining engineering. Metallurgy ,TN1-997 - Abstract
In order to manufacture complex curvilinear generatrix workpieces of high-temperature titanium alloy, the hot tensile behavior of Ti55 alloy sheet was tested and the hot press forming process was investigated using Finite Element Method (FEM) simulation and experiment. The hot tensile experiments of Ti55 rolled sheet were conducted at the temperatures of 800–900 °C with the strain rates of 0.001–0.1 s−1. According to the results of hot tensile tests and microstructure evolution, the proper hot press forming parameters were determined as the temperature of 850 °C and the strain rates of 0.001–0.01 s−1. The wrinkling mechanism in the transition region was analyzed and the initial blank sheet geometry was optimized by FE simulation of hot press forming. The two-step hot press forming process was better to produce the complex sheet workpiece of Ti55 alloy than the one-step hot forming scheme, which could restrain the wrinkling trend and ensure the microstructure and mechanical properties of the hot formed workpieces.
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- 2018
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22. Fabrication of Fe60Cu40 pre-alloy bonded composites for diamond tools by microwave hot press sintering
- Author
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Yang Li, Ming Hou, Fang Wang, Jia Lijuan, Shenghui Guo, and Jiyun Gao
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lcsh:TN1-997 ,Fabrication ,Materials science ,Alloy ,Sintering ,02 engineering and technology ,engineering.material ,01 natural sciences ,Fe60Cu40 pre-alloy ,Biomaterials ,MHPS ,0103 physical sciences ,Composite material ,lcsh:Mining engineering. Metallurgy ,010302 applied physics ,Diamond composites ,Metals and Alloys ,Diamond ,021001 nanoscience & nanotechnology ,Microstructure ,Surfaces, Coatings and Films ,Hot press ,Microwave sintering ,Ceramics and Composites ,engineering ,0210 nano-technology ,Microwave - Abstract
In this study, a microwave hot press sintering (MHPS) strategy was developed for metal-bonded diamond composites (MBDC). The main focus was on the MHPS process of Fe60Cu40 pre-alloy bonded diamond composites. The temperature rise characteristics of the metal powders were obtained within a microwave field. Further, the composition change law of the composites was determined during the sintering process by analyzing the properties and microstructure of the composites. The successful development of this strategy will provide a reliable reference for the application of microwave sintering in the fabrication of MBDC.
- Published
- 2020
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23. Effect of Y Doping and Vacuum Hot-Press Sintering on Microstructure and Mechanical Properties of TiAI-based Alloys.
- Author
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Li Yang, Sun Hongliang, Yang Kang, Deng Peng, and Chen Zhiyuan
- Abstract
Copyright of Rare Metal Materials & Engineering is the property of Northwest Institute for Nonferrous Metal Research 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.)
- Published
- 2019
24. Microstructure and atmospheric oxidation behavior of CrCuFeMnNiCox high‐entropy alloys fabricated by vacuum hot‐press sintering.
- Author
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Ren, Bo, Zhao, Rui‐feng, Jiang, Ai‐yun, and Yu, Yuan
- Subjects
- *
INTERMETALLIC compounds , *OXIDATION , *METALLIC oxides , *OXIDATION kinetics , *SINTERING , *ALLOYS - Abstract
The CrCuFeMnNiCox high‐entropy alloys (HEAs) were prepared by vacuum hot‐press sintering. The microstructure and atmospheric oxidation behavior at 800°C were studied. The phase structure of the Co0 alloy comprised the Cr‐rich FCC1 major phase, Cu‐rich FCC2 secondary phase, and a small amount of intermetallic compound ρ phase when x = 0. The bulk alloys comprised FCC2 major and FCC1 secondary phases when x ≥ 0.5. The oxidation kinetics curves approximately followed the parabolic law. A high Co content leads to a large oxidation weight gain of the alloys. The oxidation weight gain of the Co0 alloy was the smallest at approximately 4.46 mg cm−2 after atmospheric oxidation for 50 h, while the oxidation weight gain of the Co2.0 alloy was the largest at approximately 5.94 mg cm−2. The Co0 alloys exhibited the best oxidation resistance. Therefore, Co is not beneficial to the improvement of the oxidation properties of the CrCuFeMnNiCox HEAs. The main oxidation products of the HEAs mainly comprised MO, M2O3, M3O4, and (M,Cr)3O4 type metal oxides. The main oxidation mechanism was selective oxidation. [ABSTRACT FROM AUTHOR]
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- 2022
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25. Study on the effect of hot press sintering temperature on the microstructure and properties of new Ti-Al-Nb alloy
- Author
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Q.Y. Yu, M.C. Zhang, S. Fang, and H.P. Xiong
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Hot press ,Materials science ,Alloy ,Metallurgy ,engineering ,Sintering ,engineering.material ,Microstructure - Published
- 2021
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26. Microstructure, hardness, and wear properties of hot-press sintered Cr3C2/Ni3Al composites containing Cr3C2 particles of different sizes.
- Author
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Fu, Lihua, Zhou, Meng, Gao, Yuanan, Gan, Bin, Du, Sanming, Zhang, Yongzhen, Song, Chenfei, Hua, Lvdong, and Zhang, Guofeng
- Subjects
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CHROMIUM carbide , *WEAR resistance , *MECHANICAL wear , *INTERFACIAL bonding , *MATRIX effect - Abstract
In this study, Cr 3 C 2 /Ni 3 Al composites containing Cr 3 C 2 particles of different sizes were prepared via hot-press sintering. Subsequently, the effects of the size of the added Cr 3 C 2 particles on the microstructure, hardness, and tribological properties of the Cr 3 C 2 /Ni 3 Al composites were investigated. The results showed that the Ni 3 Al powder and Cr 3 C 2 particles in the composites exhibited obvious interdiffusion interactions during the hot-press sintering process and formed a new diffusion phase with an M 7 C 3 (M = Cr, Fe, and Ni) structure in the Cr 3 C 2 /Ni 3 Al composites. In addition, the diffusion effect in the composites with small Cr 3 C 2 particles was full, the proportion of the M 7 C 3 (M = Cr, Fe, and Ni) diffusion phase in the composites was greater, and the solid-solution strengthening effect of the matrix phase was evident. The hardness of the Cr 3 C 2 /Ni 3 Al composites was noticeably higher than that of the Ni 3 Al alloy because of the combination of particle, solid-solution, and refined crystalline strengthening effects. The composite with 5 μm Cr 3 C 2 particles displayed the maximum hardness (56.3 HRC) and best wear resistance. The wear mechanism results indicated that the carbide particles in the composites improved the hardness, carried the load, and blocked the movement of abrasive particles, effectively protecting the matrix from wear. However, when the added Cr 3 C 2 particles were too large, the weak interfacial bond between the chromium carbides and the matrix phases in the composites allowed the chromium carbides to easily crack and fall off, which decreased the wear resistance. [Display omitted] • The diffusion effect in the composites with small Cr 3 C 2 addition was full, and the diffusion phase content in the composites was greater. • The hardness of the Cr 3 C 2 /Ni 3 Al composites was higher than that of the Ni 3 Al alloy, and increased with decreasing Cr 3 C 2 addition size. • Cr 3 C 2 /Ni 3 Al composites with small Cr 3 C 2 addition exhibited the best wear resistance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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27. Investigation on microstructure and high strain rate behaviour of pure tantalum prepared by hot press and subsequent annealing treatment
- Author
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Hassan I. Sheikh, Saeed Reza Bakhshi, Moeen Alaei, and Gholam Hossein Borhani
- Subjects
010302 applied physics ,High strain rate ,Materials science ,Annealing (metallurgy) ,Metallurgy ,Metals and Alloys ,Refractory metals ,Tantalum ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,Hot pressing ,01 natural sciences ,Grain size ,Hot press ,chemistry ,Mechanics of Materials ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,0210 nano-technology - Abstract
Among refractory metals, tantalum has long been the primary material of use in high strain rate applications. Hot pressing (HP) is a technique to produce specimens with high density and homogeneous...
- Published
- 2019
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28. Assessment of Heat-Affected Zone Softening of Hot-Press-Formed Steel over 2.0 GPa Tensile Strength with Bead-On-Plate Laser Welding
- Author
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Kwang Soo Kim, Namhyun Kang, Minjung Kang, and Cheolhee Kim
- Subjects
Heat-affected zone ,Technology ,Materials science ,softening ,QH301-705.5 ,QC1-999 ,02 engineering and technology ,Welding ,01 natural sciences ,law.invention ,law ,Ferrite (iron) ,0103 physical sciences ,Ultimate tensile strength ,hot-press-formed steel ,General Materials Science ,Composite material ,Biology (General) ,Instrumentation ,QD1-999 ,Tensile testing ,010302 applied physics ,Fluid Flow and Transfer Processes ,Process Chemistry and Technology ,Physics ,General Engineering ,Laser beam welding ,2 GPa strength ,heat-affected zone ,tempered martensite ,021001 nanoscience & nanotechnology ,Microstructure ,Engineering (General). Civil engineering (General) ,Computer Science Applications ,ferrite ,Chemistry ,high-strength steel ,Vickers hardness test ,laser welding ,TA1-2040 ,0210 nano-technology - Abstract
High-strength hot-press-formed (HPF) steels with a fully martensitic microstructure are being widely used in the fabrication of automotive body structure, and 2.0 GPa-strength HPF steel has recently been commercially launched. However, heat-affected zone (HAZ) softening is unavoidable in welding martensitic steel. In this study, the HAZ softening characteristic of 2.0 GPa HPF steel was investigated by applying a high-brightness laser welding process, wherein the heat input was controlled by varying the welding speed. Microstructural evaluation and hardness test results showed that the base metal with a fully martensitic microstructure was changed to the same type of fully martensitic microstructure in the weld metal, while relatively soft microstructures of tempered martensite and ferrite phase were partially formed in the intercritical HAZ (ICHAZ) and subcritical HAZ (SCHAZ) areas. In the tensile test, the joint strength was 10–20% lower than that of the base metal, and the fracture initiation was estimated at the ICHAZ/SCHAZ boundary, where the lowest hardness was confirmed by the nanoindentation technique.
- Published
- 2021
29. Effect of Fe on the Microstructure and Mechanical Properties of Fe/FeAl2O4 Cermet Prepared by Hot Press Sintering
- Author
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Yungang Li, Hui Li, Jie Dang, Jinglong Liang, Kuai Zhang, Hongyan Yan, and Chuang Wang
- Subjects
Materials science ,General Chemical Engineering ,Fe/FeAl2O4 cermet ,microstructure ,Sintering ,02 engineering and technology ,mechanical properties ,Fe phase ,Inorganic Chemistry ,0203 mechanical engineering ,Flexural strength ,Phase (matter) ,hot press sintering ,lcsh:QD901-999 ,Relative density ,General Materials Science ,Ceramic ,Composite material ,Cermet ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,020303 mechanical engineering & transports ,visual_art ,Vickers hardness test ,visual_art.visual_art_medium ,lcsh:Crystallography ,0210 nano-technology - Abstract
The Fe/FeAl2O4 cermet was prepared with Fe-Fe2O3-Al2O3 powder by a hot press sintering method at 1400 °C. The raw materials for the powder particles were respectively 2 µm (Fe), 0.5 µm (Fe2O3), and 0.5 µm (Al2O3) in diameter, the sintering pressure was 30 MPa, and the holding time was 120 min. The effects of different Fe mass ratios on the microstructure and mechanical properties of Fe/FeAl2O4 cermet were studied. The results showed that a new ceramic phase FeAl2O4 could be formed by an in situ reaction during the hot press sintering. When the Fe mass ratio was increased, the microstructure and mechanical properties of the Fe/FeAl2O4 cermet showed a change law that initially became better and then became worse. The best microstructure and mechanical properties were obtained in the S2 sample, where the mass ratio of Fe-Fe2O3-Al2O3 was 6:1:2. In this Fe mass ratio, the relative density was about 94%, and the Vickers hardness and bending strength were 1.21 GPa and 210.0 MPa, respectively. The reaction mechanism of Fe in the preparation process was the in situ synthesis reaction of FeAl2O4 and the diffusion reaction of Fe to FeAl2O4 grains. The increase of the Fe mass ratio improved the wettability of Fe and FeAl2O4, which increased the diffusion rate of Fe to FeAl2O4 grains, which increased the influence on the structure of FeAl2O4.
- Published
- 2021
30. Physical and mechanical properties of hot-press sintering ternary CM2A8 (CaMg2Al16O27) and C2M2A14 (Ca2Mg2Al28O46) ceramics
- Author
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Guangqi Li, Junhong Chen, Yong Li, Xinmei Hou, Haiyang Chen, and Bin Li
- Subjects
Materials science ,Sintering ,02 engineering and technology ,mechanical properties ,01 natural sciences ,physical properties ,lcsh:TP785-869 ,Fracture toughness ,Flexural strength ,0103 physical sciences ,Relative density ,Ceramic ,Composite material ,Porosity ,C2M2A14 ,010302 applied physics ,021001 nanoscience & nanotechnology ,Microstructure ,hot-press sintering ,Electronic, Optical and Magnetic Materials ,lcsh:Clay industries. Ceramics. Glass ,CM2A8 ,visual_art ,Vickers hardness test ,Ceramics and Composites ,visual_art.visual_art_medium ,0210 nano-technology - Abstract
The new ternary CM2A8 (CaMg2Al16O27) and C2M2A14 (Ca2Mg2Al28O46) pure and dense ceramics were first prepared by a hot-press sintering technique, and their physical and mechanical properties were investigated. The purity of obtained CM2A8 and C2M2A14 ceramics reaches 98.1 wt% and 97.5 wt%, respectively. Their microstructure is dense with few observable pores, and their grain size is about a few dozen microns. For their physical properties, the average apparent porosity of CM2A8 and C2M2A14 ceramics is 0.18% and 0.13%, and their average bulk density is 3.66 g/cm3 and 3.71 g/cm3, respectively. The relative density of CM2A8 ceramic is 98.12% and that of C2M2A14 ceramic is 98.67%. The thermal expansivity (50–1400 °C) of CM2A8 and C2M2A14 ceramics is 9.24×10–6 K–1 and 8.92×10–6 K–1, respectively. The thermal conductivity of CM2A8 and C2M2A14 ceramic is 21.32 W/(m·K) and 23.25 W/(m·K) at 25 °C and 18.76 W/(m·K) and 19.42 W/(m·K) as temperature rises to 350 °C, respectively. In addition, the mechanical properties are also achieved. For CM2A8 ceramic, the flexural strength is 248 MPa, the fracture toughness is 2.17 MPa·m1/2, and the Vickers hardness is 12.26 GPa. For C2M2A14 ceramic, the flexural strength is 262 MPa, the fracture toughness is 2.23 MPa·m1/2, and the Vickers hardness is 12.95 GPa.
- Published
- 2018
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31. Effect of Mn addition in W-Ni-Cu heavy alloy processed through hot press sintering techniques on microstructure, microtexture and grain boundary character evolution.
- Author
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R, Manikandan and A, Raja Annamalai
- Subjects
- *
MICROHARDNESS , *HOT pressing , *CRYSTAL grain boundaries , *TUNGSTEN alloys , *SINTERING , *MICROSTRUCTURE , *COPPER - Abstract
In this current study, the impact of manganese addition to 93 W-4.9Ni-2.1Cu-xMn (where x = 1, 2, 3, and 4 Wt%) on the microstructure, texture development, and grain boundary character distribution of tungsten heavy alloy (WHAs) was examined. The samples were produced through a vacuum hot press sintering, with parameters 50 MPa pressure, 10 °C/min heating rate, and 1450 °C sintering temperature for 20 min holding duration. To study the influence of manganese on the texture development and microstructure in conventional WHAs, electron backscatter diffraction (EBSD) was employed. The important findings from the EBSD analysis reveal that fibre texture (001) 〈111〉 and a higher fraction of low-angle grain boundaries in the Mn unalloyed compact resulted from extensive atomic jumps between the particles at elevated temperatures. Further texture analysis on the Mn-added compacts reveals that manganese oxide (MnO) formation during liquid phase sintering led to lower densification and randomized weak fibre texture development in manganese-alloyed compacts. In addition, the texture degradation in Mn-added compacts is mainly caused by recrystallization followed by sub-structural recovery during liquid phase sintering. This study indicates that increasing manganese content in WHAs stoichiometry led to a heterogeneous distribution of binder matrix (Ni Cu) in the sintered compact. As a result, W-4.9Ni-2.1Cu-4Mn alloy revealed decreased relative density (90.70%), microhardness (389.5 HV 0.5), and electrical conductivity (15.74% of IACS). [Display omitted] • The formation of manganese oxide in Mn-added WHAs leads to a reduction in density and properties. • The addition of Mn into WHAs induces alterations in the texture orientation of Ʃ3 CSL and HAGBs. • The {111} 〈001〉 texture became weaker as the manganese stoichiometry in WHAs increased. • Hardness and conductivity showed the W-Ni-Cu alloy does not benefit from Mn. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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32. The Microstructure and Properties of Al–Mn–Cu–Zr Alloy after High-Energy Ball Milling and Hot-Press Sintering.
- Author
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Yakovtseva, Olga A., Mochugovskiy, Andrey G., Prosviryakov, Alexey S., Bazlov, Andrey I., Emelina, Nadezhda B., and Mikhaylovskaya, Anastasia V.
- Subjects
MICROSTRUCTURE ,BALL mills ,SINTERING ,ALLOYS ,STEARIC acid ,MECHANICAL alloying - Abstract
In the present research an Al–7.7%Mn–4.9%Zr–3.2%Cu (wt%) alloy was processed by mechanical alloying (MA) followed by hot press sintering. The microstructure, phase composition, and mechanical properties of the MA granules and sintered samples were investigated. The dissolution of Mn, Zr, and Cu with further precipitation of the Al
6 Mn phase were observed during high-energy ball milling. In the alloy processed without stearic acid after milling for ~10 h, an Al-based solid solution with ~4.9 wt%Zr, ~3.2 wt%Cu and a ~5 wt%Mn with a grain size of ~16 nm and a microhardness of ~530 HV were observed. The addition of stearic acid facilitated Mn dissolution and precipitation of the Al6 Mn phase during milling but led to the formation of the ZrH2 phase that decreased the Zr solute and the microhardness. Precipitation of the Al6 Mn, L12 –Al3 Zr, and Al2 Cu phases during annealing and sintering of the MA granules in the temperate range of 350–375 °C was observed, and an additional Al20 Cu2 Mn3 phase was precipitated at 400–450 °C. Hot-press sintering at 450 °C provided a low fraction of cavities of ~1.5%, the yield strength of 1100 MPa, ultimate compressive strength of 1200 MPa, strain at fracture of 0.5% at room temperature, the yield strength of 380 MPa, ultimate compressive strength of 440 MPa, and strain at fracture of 3.5% at 350 °C. The microstructural evolution during high-temperature deformation on the sample surface was studied and the differences in deformation behavior for the alloys sintered at different temperatures were discussed. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
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33. Study on Squeeze Casting Metal-zirconium Composite Die Material by Hot Press Sintering
- Author
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Yonggen Sun, Yanhan Fei, Zhiming Du, Chen Lili, and Yuansheng Cheng
- Subjects
Thermal shock ,Materials science ,business.product_category ,Composite number ,Sintering ,Microstructure ,visual_art ,Shear strength ,visual_art.visual_art_medium ,Die (manufacturing) ,General Materials Science ,Ceramic ,Composite material ,business ,Yttria-stabilized zirconia - Abstract
ZrO2-5CrMnMo composite samples were prepared by hot press sintering. When NiCoCrAlY powders were used as the bonding layer and the different mixtures of NiCoCrAlY alloy and 3YSZ (3mol% yttria stabilized zirconia) ceramic powders were used as the transition layers, the connection between zirconia ceramic and 5CrMnMo steel were strengthened. Three composite samples with different structures were fabricated by heat spraying and hot press sintering. Shear and thermal shock cycle tests were conducted to characterize connection strength and thermal shock resistance of these samples. The shear strength reached 95.69 MPa, and the heating shock cycles achieved to the maximum value of 27.7 times. Microstructures and connection interfaces were analyzed by scanning electron microscopy. The hardness and wearing resistance of 3YSZ coat and 5CrMnMo substrate were compared, and the heat insulation property of composite samples were also discussed. It is shown that these composite materials fabricated in this research are benefited to be used as squeeze casting dies.
- Published
- 2021
- Full Text
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34. Microstructure and Mechanical Properties of 7055 Al Alloy Prepared by Hot-Press Sintering of Powder Byproduct and Optimization of Sintering Parameters
- Author
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Chao Liu, Yunzhu Ma, Wensheng Liu, Yufeng Huang, Tao Wang, Yan Huanyuan, Wu Lei, and Lun Yang
- Subjects
Equiaxed crystals ,Materials science ,Metallurgy ,Alloy ,General Engineering ,Sintering ,chemistry.chemical_element ,Raw material ,engineering.material ,Microstructure ,Taguchi methods ,chemistry ,Aluminium ,Ultimate tensile strength ,engineering ,General Materials Science - Abstract
Powder byproduct is inevitably produced during spray-forming of 7055 aluminum alloy, greatly reducing the utilization rate of raw materials and increasing production costs. To make such powder byproduct into valuable products, 7055 alloy was prepared by hot-press sintering of powder byproduct in this work. The characteristics of the powder byproduct were studied comprehensively. The microstructure and properties of the as-sintered 7055 alloy were investigated, and the parameters of the hot-press sintering process were optimized using the Taguchi method. The results indicated that the microstructure of the as-sintered alloy was very compact and the grains typically had equiaxed structure, with the main precipitated phase being MgZn2. The tensile strength of the alloy prepared by hot-press sintering with parameters of sintering temperature of 560°C, holding time of 150 min, and pressure of 12 MPa was 287.29 MPa.
- Published
- 2021
- Full Text
- View/download PDF
35. Effect of process parameters on the microstructure and mechanical properties of vacuum hot-press sintered Co-50 mass% Cr alloys
- Author
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Kuo-Tsung Huang, Ming-Wei Wu, Shih-Hsien Chang, and Chih-Yao Chang
- Subjects
010302 applied physics ,Materials science ,Metallurgy ,Metals and Alloys ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,01 natural sciences ,Hot press ,Mechanics of Materials ,Scientific method ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,0210 nano-technology - Published
- 2018
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36. Effects of untransformed ferrite on Charpy impact toughness in 1.8-GPa-grade hot-press-forming steel sheets
- Author
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Jaeyeong Park, Jin-Keun Oh, Min Cheol Jo, Seok Su Sohn, Sunghak Lee, and Seongwoo Kim
- Subjects
Toughness ,Materials science ,020502 materials ,Mechanical Engineering ,Metallurgy ,Charpy impact test ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,Hot press ,0205 materials engineering ,Mechanics of Materials ,Martensite ,Ferrite (iron) ,Ultimate tensile strength ,General Materials Science ,Deformation bands ,Composite material ,0210 nano-technology - Abstract
Hot press forming (HPF) steel sheets are austenitized, press-formed, and rapidly cooled to obtain a martensitic microstructure with an ultra-high strength. When they are insufficiently austenitized, their microstructures might contain a small amount of untransformed ferrite, which can deteriorate impact toughness as well as strength, but its causes and relevant fracture mechanisms have not been clearly verified yet. In this study, thus, 1.8-GPa-grade HPF sheets were austenitized at various temperature and time, and their tensile and Charpy impact test results were analyzed in relation with untransformed ferrite and its effect on fracture mechanisms. In the HPF sheets containing the untransformed ferrite, voids were formed mostly at ferrite/martensite interfaces, and were grown and propagated linearly to form a cleavage crack, whereas deformation bands were well developed without voids or cracks in the non-ferrite-containing sheets. The highly localized strains accommodated in the soft ferrite made ferrite/martensite interfaces or ferrite itself work as fracture initiation sites, which led to the brittle fracture and consequently to the deterioration of impact energy. This result can provide an important idea for optimization of austenitization conditions demanded for ultra-high strength and excellent impact toughness in HPF applications.
- Published
- 2017
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37. Influence of pressure on interfacial microstructure evolution and atomic diffusion in the hot-press bonding of Ti-33Al-3V to TC17
- Author
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Lixing Sun, Chao Yang, Miaoquan Li, and Hong Li
- Subjects
010302 applied physics ,Void (astronomy) ,Materials science ,Mechanical Engineering ,Alloy ,Metals and Alloys ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Hot press ,Atomic diffusion ,Crystallography ,Bond line ,Mechanics of Materials ,Phase composition ,0103 physical sciences ,Materials Chemistry ,engineering ,Composite material ,0210 nano-technology ,Shrinkage - Abstract
Joining of TiAl to Ti alloy is a potential requirement for manufacturing the components with dual properties. In this paper, the hot-press bonding of Ti-33Al-3V to TC17 was implemented at different pressures and the temperature of 850 °C for 10 min with post bond heat treatment. The influence of pressure on interfacial microstructure evolution and atomic diffusion was analyzed in detail. The microstructure observation and phase composition analysis on the bond indicate that the metallurgical bonding of Ti-33Al-3V/TC17 is produced at pressures of 23–50 MPa, and an interfacial zone with a certain width forms between base alloys. A new α 2 (Ti 3 Al) phase is generated in the interfacial zone. The influence of pressure on the metallurgical bonding of Ti-33Al-3V/TC17 includes two aspects. One is to promote the void shrinkage in the interfacial zone. The quantitative analysis of voids shows an increase in pressure induces a decrease in amount and size of voids. The highest bonding ratio of 96.3% can be obtained at the pressure of 50 MPa with post bond heat treatment. The second is to promote the atomic diffusion across bond line. The diffusion distances of Ti and Al atoms increase with an increase in pressure and the width of the interfacial zone shows a linear increasing law with the pressure. Moreover, a higher pressure induces a higher increment in atomic diffusion distance and width of the interfacial zone in the post bond heat treatment.
- Published
- 2017
- Full Text
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38. A novel vacuum/oxygen hot press sintering approach for the fabrication of transparent PLZT (7.4/70/30) ceramics
- Author
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Xiyun He, Liang Ling, Xia Zeng, Pingsun Qiu, Dazhi Sun, and Haijun Cheng
- Subjects
010302 applied physics ,Fabrication ,Materials science ,Scattering ,Process Chemistry and Technology ,Sintering ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Lead zirconate titanate ,Microstructure ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Phase (matter) ,visual_art ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Ceramic ,Composite material ,0210 nano-technology ,Lead oxide - Abstract
Transparent Lanthanum-modified lead zirconate titanate ceramics (PLZT 7.4/70/30) with low content of excess lead oxide (PbO) were successfully prepared by a novel vacuum/oxygen hot press sintering process. The phase structure, microstructure, electrical properties and electro-optic scattering performance of PLZT ceramics as a function of excess PbO in the starting powders have been studied and analyzed. As a result, these ceramics exhibited an ultra-high optical transmittance (>69.4% at 1064 nm; thickness 1 mm) from visible to near-infrared wavelength. Herein, we significantly reduce the use of PbO as an auxiliary agent for sintering. This puts forward a good route to meet the objectives of environmental protection and sustainable development.
- Published
- 2021
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- View/download PDF
39. Microstructural and wear properties of the Al-B4C composite coating produced by hot-press sintering on AA-2024 alloy
- Author
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C. Ozay, H. Ballikaya, O. E. Karlidag, and F. Dagdelen
- Subjects
Materials science ,Mechanical Engineering ,Alloy ,Sintering ,Substrate (electronics) ,engineering.material ,Microstructure ,Indentation hardness ,Coating ,Mechanics of Materials ,engineering ,Particle ,Composite material ,Layer (electronics) - Abstract
In this study, the surface of an AA-2024 alloy was covered with reinforced composite coating using hotpress sintering method. Al and B4C powders were synthesized through mechanical alloying technique and coated on the AA-2024 substrate at different rates. The microstructure of the intermediate transition region formed between the substrate (AA-2024 Al alloy) and the coating layer (Al/B4C MMCs), the microstructure of the Al/B4C metal matrix composites (MMCs) coating, the microhardness, and the adhesive wear resistance of the Al/B4C MMCs coating layer were investigated. It was observed that B4C powders homogeneously dispersed in the microstructure of the Al/B4C MMCs coating layer, moreover, the Al matrix and B4C reinforcement particles were bonded without a gap. It was also determined that an interface bonding occurred between Al/B4C MMCs coating layer and the AA-2024 substrate. Accordingly, it was determined that with the increase of B4C reinforcement particle ratio, the hardness of the coating layer, and the wear resistance increased.
- Published
- 2021
- Full Text
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40. Effects of TiC particle size on microstructures and mechanical properties of B4C–TiB2 composites prepared by reactive hot-press sintering of TiC–B mixtures
- Author
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Zetan Liu, Xiang Ding, Pan Kaikai, Xiangong Deng, Zhu Jianhua, Jiamao Li, and Songlin Ran
- Subjects
010302 applied physics ,Materials science ,Process Chemistry and Technology ,Composite number ,Sintering ,02 engineering and technology ,Abnormal grain growth ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Amorphous solid ,Impurity ,Phase (matter) ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,Particle size ,Composite material ,0210 nano-technology - Abstract
Effects of the starting TiC particle size on the phase compositions, microstructures and mechanical properties of B4C–TiB2 composites prepared by reactive hot-press sintering of TiC–B mixtures were investigated. B4C–TiB2 composites were prepared from a single grade amorphous B powder (0.9 μm) and three different TiC powders (50 nm, 0.8 μm and 3.0 μm), respectively. The composites prepared from 50 nm and 3.0 μm TiC powders exhibited finer microstructures and higher hardness (29–30 GPa). The composite prepared from 0.8 μm TiC powder showed the coarsest microstructure but possessed the highest strength of 659 MPa due to its homogenous phase distribution without C impurity and abnormal grain growth that presented in the other two composites. The results indicated that the mechanical properties of B4C–TiB2 composite could be controlled by the particle size matching between TiC and B powders.
- Published
- 2020
- Full Text
- View/download PDF
41. Mechanical properties of B4C–SiC composites fabricated by hot-press sintering
- Author
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Woo Hyuk Choi, Yun-Soo Lim, Min Suk Kim, Hyungsun Kim, Sung Min So, Jongee Park, Kyoung Hun Kim, and Joo Seok Park
- Subjects
010302 applied physics ,Materials science ,Process Chemistry and Technology ,Composite number ,Sintering ,Crystal growth ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Carbide ,Flexural strength ,0103 physical sciences ,Vickers hardness test ,Materials Chemistry ,Ceramics and Composites ,Relative density ,Composite material ,0210 nano-technology - Abstract
We fabricated boron carbide-silicon carbide (B4C–SiC) composites by hot-press sintering without additives and evaluated the crystal phase, relative density, microstructure, and mechanical properties of the sintered body. When B4C and SiC were uniformly dispersed in the composite, crystal growth was inhibited, and a sintered body with a fine and uniform microstructure, with improved mechanical properties, was fabricated. The relative density of B4C–SiC composites sintered at temperatures lower than 2000 °C and 40 MPa of pressure exceeded 99.8%, and the bending strength and Vickers hardness at B4C 50 wt% were 645 MPa and 30.6 GPa, respectively.
- Published
- 2020
- Full Text
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42. Material Flow Behavior and Microstructure Evolution During Direct Hot‐Press Bonding of Ti/Mg Laminates with Interlocking Structure
- Author
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Bin Shao, Debin Shan, Yingying Zong, Tang Wei, and Bin Guo
- Subjects
Hot press ,Materials science ,General Materials Science ,Composite material ,Condensed Matter Physics ,Microstructure ,Interlocking ,Material flow - Published
- 2021
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43. Hot-Press Sintering of Tic0.5N0.5-Based Cermets: Addition Effect of AlN Nano-Powder on Microstructure and Mechanical Properties
- Author
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Chang Chun Lv, Zhi Jian Peng, Cheng Biao Wang, and Yu Jia Zhai
- Subjects
Hot press ,Materials science ,Fracture toughness ,Flexural strength ,Mechanics of Materials ,Mechanical Engineering ,Nano ,Vickers hardness test ,Sintering ,General Materials Science ,Cermet ,Composite material ,Microstructure - Abstract
TiCN-based cermets were prepared by hot-press sintering through adding various amounts of AlN nanopowder (0-20 wt.%) into a 64 wt.% TiC0.5N0.5-10 wt.% WC-8.5 wt.% Mo-12.5 wt.% Ni-5 wt.% Co system. The microstructure and mechanical properties of the prepared cermets were investigated. For the prepared cermets, samples with 5 wt.% AlN nanopowder exhibited optimum mechanical properties of Vickers hardness 2191 HV10, bending strength 601 MPa, and fracture toughness 6.03 MPa.m1/2, respectively.
- Published
- 2017
- Full Text
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44. New utilization approach of microwave thermal energy: Preparation of metallic matrix diamond tool bit by microwave hot-press sintering.
- Author
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Ye, Xiaolei, Guo, Shenghui, Yang, Li, Gao, Jiyun, Peng, Jinhui, Hu, Tu, Wang, Liang, Hou, Ming, and Luo, Qiyue
- Subjects
- *
INDUSTRIAL diamonds , *MICROWAVES , *SINTERING , *MECHANICAL behavior of materials , *MICROSTRUCTURE - Abstract
Sintering is a critical process for the preparation of metallic matrix diamond tools. The purpose of this work aims to propose a novel microwave hot-press sintering (MHPS) method for the improvement of mechanical properties for Fe-Cu-W-Sn matrix diamond tools. The samples were prepared by MHPS and conventional hot-press sintering (CHPS), respectively. The microstructures of samples were characterized using XRD, EMPA, and SEM tests. The mechanical properties of samples, such as relative density, hardness, bending strength, and impact toughness were also investigated. Experimental results show that the samples by MHPS method has obvious advantages with shorter sintering time, lower sintering temperature, more uniform element diffusion, and better holding situation of diamond abrasives in the alloyed matrix. The optimal mechanical properties of samples sintered by MHPS at 850 °C, to be specific, including relative density, hardness and flexural strength reach 97.8%, 99.2 HRB and 986 MPa, respectively. The possible mechanism of MHPS is discussed. This work can provide a reference for microwave sintering of metallic matrix diamond tools. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
45. Effect of pre-sintering particle size on the microstructure and magnetic properties of two-step hot-press prepared BaFe12O19 thick films.
- Author
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Dong, Anjiang, Liu, Ranyang, Tian, Zeqiang, Peng, Feng, Zhao, Run, Su, Xiaodong, and Tang, Rujun
- Subjects
- *
THICK films , *MAGNETIC properties , *MAGNETIC fields , *ACTIVATION energy , *MICROSTRUCTURE - Abstract
Both particle size and processing conditions can affect the magnetic properties of ferrite materials. In this work, the two-step hot-press procedures (hot-press magnetic orientation followed by hot-press sintering) is designed for fabrication of high quality BaFe 12 O 19 thick films. The effects of pre-sintering particle size (G pre) on the microstructure and magnetic properties of the thick films are investigated. Results show that reducing G pre increase c -axis orientation and remanence ratio (RR) of sintered thick film greatly. This should be due to the reduced energy barriers for grain orientation during the hot-press magnetic orientation process. Decreasing G pre from 920 nm to 170 nm leads to larger coercivity (H c), while the saturation magnetization does not change notably above G pre = 170 nm. The H c mechanism is further analyzed by the G pre dependent anisotropy field H k and the first-order-reversal curves of the thick film. Results show that H k increases with reducing G pre , while the inter-grain interactions are not notably affected by G pre. Therefore, the increase of H c should be contributed by both the decrease of sintered particle size and the improved RR of the film after hot-press magnetic field orientation. The above results show that the two-step hot-press sintering prepared hexaferrite thick films with optimized G pre is a good candidate for the realization of self-biased high frequency devices. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
46. Interpretation of surficial shear crack propagation mechanisms in bending for Zn or AlSi coated hot press forming steels.
- Author
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Kim, Selim, Jo, Min Cheol, Kim, Seongwoo, Oh, Jinkeun, Kim, Sang-Heon, Sohn, Seok Su, and Lee, Sunghak
- Subjects
- *
CRACK propagation , *HOT pressing , *STEEL , *PEAK load , *MICROSTRUCTURE - Abstract
The bending angle at the peak load is regarded as the most important parameter for evaluating bending properties of hot-press-forming (HPF) steels. However, it is not a mechanics-based parameter for the bending criterion, and the data interpretation is difficult because bending criteria in relation with microstructures and associated bending mechanisms have not been verified yet. In this study, effects of coating and baking treatments on bending angles at the peak load of three kinds of 1470 MPa-grade HPF steels were investigated by interrupted three-point bending tests coupled with direct microstructural observation. According to direct observations of sequential cracking processes of V-shaped crack (V-crack), bending procedures were classified into four stages: (1) formation of small V-crack, (2) increase in number and size of V-cracks, (3) initiation of shear-crack propagation from the V-crack tip, and (4) further propagation and opening of the shear crack. The minimum bending angle required for initiating the shear-crack propagation from the V-crack tip was defined as a critical angle, which meant the boundary between the 2nd and 3rd stages. The present bending behavior related with critical bending angle and V-cracking could be interpreted similarly by the fracture-mechanics concept, i.e., the initiation of shear-crack propagation. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
47. Hot-press sintering K0.5Na0.5NbO3–0.5 mol%Al2O3 ceramics with enhanced ferroelectric and piezoelectric properties
- Author
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Xiao-ming Chen, Jian-Ping Zhou, Peng Liu, Yu-long Su, Jiang-bo Lu, Han-li Lian, and Zi-de Yu
- Subjects
Piezoelectric coefficient ,Materials science ,Annealing (metallurgy) ,Mechanical Engineering ,Sintering ,Microstructure ,Piezoelectricity ,Ferroelectricity ,Mechanics of Materials ,visual_art ,visual_art.visual_art_medium ,General Materials Science ,Thermal stability ,Ceramic ,Composite material - Abstract
Lead-free ceramics K0.5Na0.5NbO3–0.5 mol%Al2O3 with simple composition were prepared via the hot-press sintering. The ceramics exhibit dense microstructure, fine grains, and pure orthorhombic structure. Via the hot-press sintering as well as adding 0.5 mol%Al2O3 into K0.5Na0.5NbO3, piezoelectric and ferroelectric properties of the obtained ceramics were obviously enhanced. The ceramics exhibit high remnant polarization Pr = 26.8 μC/cm2 and piezoelectric constant d33 = 137 pC/N. The maximum unipolar strain is 0.17%, and the converse piezoelectric coefficient d33* is 212 pm/V under electric field E = 80 kV/cm. Under E = 50 kV/cm, the Pr increases from 21.6 to 22.2 μC/cm2, and the d33* increases from 223 to 322 pm/V as the temperature increases from room temperature to 170 °C. The ex situ measurement result demonstrates that d33 still keeps a high value of 97 pC/N as the annealing temperature increases to 380 °C, implying excellent thermal stability.
- Published
- 2019
- Full Text
- View/download PDF
48. Tailoring the microstructure of Al/Ti laminated composite through hot press sintering process to achieve superior mechanical properties.
- Author
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Que, Biaohua, Chen, Liang, Qian, Lihua, Kong, Xiangshan, and Zhao, Guoqun
- Subjects
- *
HOT pressing , *LAMINATED materials , *MICROSTRUCTURE , *SINTERING , *SISAL (Fiber) , *RECRYSTALLIZATION (Metallurgy) - Abstract
A novel method based on hot press sintering was proposed to fabricate the Al/Ti laminated composite, and the effects of sintering parameters on microstructure, interfacial structure, and mechanical properties were thoughtful examined. The results showed that insufficient sintering caused obvious voids and cracks at Al/Ti interface. With the increase of temperature or holding time, a good metallurgical bonding without defects was achieved, and both the recrystallization fraction and grain size of α phase in Ti layer increased, accompanied by the transformation of α to β phase and growth of intermetallic phase. The microstructure variation of Al layer is not evident with changing the sintering parameters. Due to the relatively low formation energy, the nanoscale TiAl 3 phase with massive stacking faults formed at Al/Ti interface, and lots of dislocations existed at Al layer near the interface. The voids and cracks formed at Al/Ti interface led to the premature failure of laminate. On the basis of the metallurgical bonding and small TiAl 3 phase, the high fraction and texture intensity of α phase were the dominated strengthening factors. Moreover, the back stress generated at Al/Ti interface contributes to an extra strengthening. The superior mechanical properties of Al/Ti laminate with a tensile strength of 670.9 MPa and a fracture strain of 0.33 were obtained with the sintering temperature of 600 °C and holding time of 2 h. [Display omitted] • A superior combination of strength and fracture strain of Al/Ti laminate was obtained by hot press sintering. • Grain size, recrystallization fraction, and texture intensity of α phase were sensitive to sintering parameters. • Nanoscale TiAl 3 phase with massive stacking faults formed toward Al layer at Al/Ti interface. • Achieving metallurgical bonding and minimizing the size of TiAl 3 facilitate a strong strengthening effect. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. Microstructure and Mechanical Properties of Boron Sheet Metal Steels in Hot Press Forming Process With Nanofluid as Coolant
- Author
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Syh K. Lim and Ahmad Razlan Yusoff
- Subjects
Hot press ,Nanofluid ,Materials science ,chemistry ,visual_art ,Metallurgy ,visual_art.visual_art_medium ,Forming processes ,chemistry.chemical_element ,Microstructure ,Sheet metal ,Boron ,Coolant - Published
- 2019
- Full Text
- View/download PDF
50. Effect of Al addition on the microstructures and compression properties of (TiCxNy–TiB2)/Ni composites fabricated by combustion synthesis and hot press
- Author
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Shili Shu, Yawei Wang, Qi-Chuan Jiang, Feng Qiu, and Rui Zuo
- Subjects
Hot press ,Materials science ,Compressive strength ,General Chemical Engineering ,visual_art ,Powder metallurgy ,Al content ,Composite number ,visual_art.visual_art_medium ,Ceramic ,Composite material ,Combustion ,Microstructure - Abstract
The 70 wt.% (TiC x N y –TiB 2 )/Ni composites were fabricated successfully by the combustion synthesis and hot press consolidation of the Ni–Ti–Al–B 4 C–BN powder mixtures. The addition of Al to Ni–Ti–B 4 C–BN system significantly decreased the ignition difficulty of combustion synthesis, and improved the compression properties of (TiC x N y –TiB 2 )/Ni composites. The final products mainly consist of Ni, TiC x N y and TiB 2 , and the ceramic particles distribute uniformly in the composites. With increasing Al content from 0 to 8 wt.%, the average sizes of the TiC x N y and TiB 2 particles decrease a little, while the hardness and the compression strength increase firstly and then decrease, and the fracture strain increases. The composite with optimal 5 wt.% Al possesses the best comprehensive properties: the highest hardness (1794 Hv), the superior compression strength (3.76 GPa), and the fracture strain (4.2%), resulting in an overall increase by ~ 15%, ~ 28%, and ~ 45%, compared with these of the composite without the Al addition, respectively.
- Published
- 2015
- Full Text
- View/download PDF
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