Search

A novel approach was proposed, based on the application of the fuzzy logic (FL) method for the fast analysis of the hot deformation process of 80MnSi8-6 steel. In the first stage, the curves developed from plastometric tests and the results of studies of the microstructure of the deformed samples were used as input data for the analysis. Input and output variables were adopted and a set of rules based on cause-and-effect relationships was defined, defining the interactions between the variables. A fast FL-controller was designed, and the correctness of its operation was verified by comparison with experimental results and the results of finite element method (FEM) analysis, carried out taking into account the evolution of the microstructure. The process of hot compression under isothermal conditions of 80MnSi8-6 steel specimens was simulated on the Warmumformsimulator (WUMSI), assuming such parameters and other conditions as were used in real tests. It was confirmed that the proposed method, based on the analysis of flow curves and prior austenite grain size using a fuzzy controller, gave satisfactory results. Subsequently, a novel FL-controller was developed to analyze the kinetics of dynamic recrystallization (DRX), using data obtained from the author's model of this phenomenon for its construction and calibration. The correctness of the controller was confirmed by comparing the results of its DRX volume fraction calculations with the distributions of this value determined by the model and the model-based FEM analysis method, respectively. It was shown that FL is applicable also when a model of the analyzed phenomenon is available. Unlike model-based calculations, a properly designed controller allows the indication of deviations from general trends that can be pointed out and interpreted by a human expert, but significantly faster. It can also serve as a component of a system analyzing complex processes, such as hot multi-stage forging. Fuzzy controller can be used in parallel with modeling or replace models in calculations. [ABSTRACT FROM AUTHOR]

This study investigates the microstructure and hardness of weld metals used in liquid hydrogen storage tanks, with a focus on the effects of three welding methods: Gas Tungsten Arc Welding (GTAW), Submerged Arc Welding (SAW), and Shielded Metal Arc Welding (SMAW). Finite element simulations were employed to model the temperature field during welding, aiding in the explanation of observed microstructural differences. The results show that while GTAW and SMAW produce weld metals with similar microstructures, SAW generates significantly larger grains with a pronounced preferential orientation. The use of weaving techniques play a key role in shaping the solidification microstructures. Additionally, the hardness of the weld metal is comparable to that of the base material, with a slight reduction corresponding to increased grain size. This research offers valuable insights into optimizing welding processes for liquid hydrogen storage tanks by addressing the microstructural characteristics that influence weld joint performance. [ABSTRACT FROM AUTHOR]

Recent research shows that integrating lithium metal anodes can enhance battery energy density, but the high reactivity of lithium requires handling under inert conditions to avoid degradation. To overcome this, reservoir‐free cells (RFCs) are explored, where lithium metal is electrodeposited at the current collector (CC) and solid electrolyte (SE) interface during initial charging. The electrochemical properties of electrodeposited lithium are influenced by its morphology and microstructure, which impact lithium discharge capacity and pore formation. However, little is known about how to control the microstructure of electrodeposited lithium. This work experimentally characterizes the lithium microstructure at the steel|Li6PS5Cl interface using cryogenic ion beam milling, scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD), focusing on the effects of electrodeposition current density and lithium layer thickness. The results show that layer thickness, not current density, primarily governs the lithium microstructure. This “specimen thickness effect” is qualitatively described using a Monte Carlo Potts model and indicates that electrodeposited lithium metal quickly equilibrates at room temperature. [ABSTRACT FROM AUTHOR]

Wire electrochemical micro-machining (WECMM) is a key focus in the realm of metal microstructure processing. Its primary advantage lies in the ability to mold metal micro zero devices. The precision of WECMM hinges on its processing gap, with the end gap determined by changes in slit length and the side gap by changes in slit width. Quantitative processing of WECMM can only be achieved when the rules governing these gaps are clearly understood. In classical electrolysis theory, the end gap is much smaller than the side gap, and whether the relationship between the two in the electrochemical transient reaction is also to be verified. While the side gap can be directly calculated using slit width and wire electrode diameter, the end gap requires measurement. Since the wire electrode is continuously fed during processing, online measurement of the end gap is not feasible at this stage, necessitating offline measurement with a fixed wire electrode and workpiece. This paper proposes an in situ electrodeposition method to precisely maintain the relative position between the wire electrode and the workpiece, ensuring measurement accuracy. Simulation tests optimize the deposition electric field and method while observing gap distribution after filling through three-dimensional layering validating the reliability of the in situ electrodeposition method. This enables accurate and effective measurement, clarifying the scale relationship between the end gap and the side gap. This, in turn, lays a foundation for understanding the distribution law of the processing gap and further improves the basic principle of WECMM. [ABSTRACT FROM AUTHOR]

Critical to the growth of digital manufacturing is the development of rapid yet accurate quality control technologies to assess the microstructure of each metal part produced. Typical surface analysis methods are limited in measurement throughput and impose constraints on maximum area size and surface quality, which enforce the tedious practice of extracting and preparing flat, small-scale samples for microstructure analysis. Here, we propose a new approach based on directional reflectance microscopy (DRM) which can yield part-scale microstructure information nondestructively and on curved, complex surfaces. We demonstrate our approach on the airfoil of a turbine blade and carry out a rigorous error analysis using other samples with variable surface geometry. Our results highlight the potential for part-specific quality control in the context of digital manufacturing. [ABSTRACT FROM AUTHOR]

The Ce‐containing novel cryogenic high‐Mn austenitic steel weld metals under different heat inputs are prepared by submerged‐arc welding to provide a satisfactory welding parameter scheme and further optimize its cryogenic impact toughness. The effect of heat input on microstructure, inclusion, and cryogenic impact toughness of weld metals are investigated via optical, scanning electron microscopy, electron backscatter diffraction, electronic probe microanalyzer, and cryogenic impact test. The results show that the dendrite arm spacing, segregation ratio of Mn, Si, and C elements and average effective grain size of the weld metals gradually increase, and the proportion of high‐angle grain boundaries decrease with the heat input increase from 11.91 to 20.24 kJ cm−1. The type of inclusions of weld metal with different heat inputs are all Ce2O3 and Ce2O2S. The number density of inclusions decreases monotonically from 5976 to 4912 mm−2, while the average size increases from 0.32 to 0.45 μm with the heat input increased. The increase in heat inputs consistently decreases the mean cryogenic impact toughness of weld metals from 123 to 102 J. The higher proportion of high‐angle grain boundaries and finer inclusions at lower heat input play the critical role in improving the cryogenic impact toughness. [ABSTRACT FROM AUTHOR]

Liquid metal (LM) elastomer composites offer promising potential in soft robotics, wearable electronics, and human‐machine interfaces. Direct ink write (DIW) 3D printing offers a versatile manufacturing technique capable of precise control over LM microstructures, yet challenges such as interfilament void formation in multilayer structures impact material performance. Here, a DIW strategy is introduced to control both LM microstructure and material architecture. Investigating three key process parameters–nozzle height, extrusion rate, and nondimensionalized nozzle velocity–it is found that nozzle height and velocity predominantly influence filament geometry. The nozzle height primarily dictates the aspect ratio of the filament and the formation of voids. A threshold print height based on filament geometry is identified; below the height, significant surface roughness occurs, and above the ink fractures, which facilitates the creation of porous structures with tunable stiffness and programmable LM microstructure. These porous architectures exhibit reduced density and enhanced thermal conductivity compared to cast samples. When used as a dielectric in a soft capacitive sensor, they display high sensitivity (gauge factor = 9.0), as permittivity increases with compressive strain. These results demonstrate the capability to simultaneously manipulate LM microstructure and geometric architecture in LM elastomer composites through precise control of print parameters, while maintaining geometric fidelity in the printed design. [ABSTRACT FROM AUTHOR]

This article presents an experimental study on the mechanical properties, creep behavior, and microstructure of an Al 1050/Mg AZ31B-laminated metal composite (LMC), due to limited studies in the analysis of creep and prediction of its behavior for the first time. The fabrication process involved preheating Al 1050 and Mg AZ31B sheets to 400 °C for 20 min, followed by rolling with a 40% reduction ratio in thickness. The investigation of mechanical properties and creep behavior under three different loadings, namely 35 MPa at 225 °C, 35 MPa at 275 °C, and 30 MPa at 225 °C, revealed the formation of a 6.7-micron atomic diffusion layer at the interface during roll bonding. With the increasing temperature at constant stress, an intermetallic compound formed adjacent to the aluminum, resulting in a 68% increase in interface thickness and a 36% decrease in creep failure time due to strength reduction. However, an increase in stress levels at a constant temperature did not have a significant effect on the interface thickness, as it only decreased by 13% and the creep failure time did decline by 44%. It can be observed that creep curves are influenced by the applied stress and temperature. Specifically, the slope of the curve increased by 40% with higher stress levels, while it decreased by approximately 2% with higher temperatures. Additionally, recrystallization was seen in the microstructure of the laminated metal sheet, whereas deformation bands and solidified melts were observed in the magnesium microstructure. [ABSTRACT FROM AUTHOR]

Two advanced manufacturing processes, spark plasma sintering (SPS) and selective laser sintering (SLS), have been developed for synthesis of (Zr,Nb,Ta,Ti,W)C compositionally complex carbide (CCC) via reactive sintering of a powder mixture of constitute monocarbides. X‐ray diffraction analysis confirmed that the single‐phase CCC can be formed by both SPS and SLS. While a homogenous microstructure with uniform metal element distributions was developed during SPS, three‐layer microstructures with a thin TiC‐rich layer and two TaC‐rich layers along with a TiO2‐rich surface layer containing W nanoparticles were formed during SLS. In addition, cellular structures with W, Zr, and Ti element segregation and dislocations on cell boundaries were observed in the SLS‐CCC sample, indicating the effect of nonequilibrium conditions on microstructure formation during laser melting followed by rapid cooling and solidification process. Compared to the SPS‐CCC sample, the SLS‐CCC showed enhanced hardness and reduced thermal conductivity, which may be related to their unique cellular structures. [ABSTRACT FROM AUTHOR]

Nanostructured melt-spun aluminum A356 flakes were consolidated into bulk samples through hot pressing. The effects of rapid solidification and pressing conditions on the microstructure and mechanical properties of the alloy were investigated using x-ray diffractometer (XRD), optical microscopy (OM), field emission scanning electron microscopy (FE-SEM), microhardness, tensile and compression tests. The results indicate modification of the eutectic morphology to a fine fibrous one with uniform distribution due to the rapid solidification. The microstructure consists of homogenous dendritic structure with ultrafine size and spherical eutectic Si crystals with the diameter of about 50 nm. These factors increase microhardness (119 ± 8 HV) much higher than those made by conventional direct casting (DC) methods. As-spun ribbons also show high ultimate tensile strength (UTS) of 420 ± 25 MPa and a plastic strain of about 10 pct. Moreover, hot consolidation of as-spun flakes result in an ultrafine-structured bulk alloy, which has ideal interflake bonding, good microhardness (95 ± 6 HV) and high strength 285 ± 10 MPa due to the refined microstructure and the extended solubility of silicon in α-Al during the controlled consolidation method. [ABSTRACT FROM AUTHOR]

Metal oxide aerogels, inorganic cousins of the highly commercialized metalloid oxide silica aerogels, exhibit distinct properties specific to each type. Nevertheless, they share a common challenge with silica aerogels—brittleness and low mechanical strength due to their particulate necklace‐like structure. In contrast, polymer aerogels often boast significantly enhanced mechanical properties thanks to their nanofibrillated networks. To enhance the mechanical properties of metal oxide aerogels, the metal oxide formation with a polymeric nanostructure is micro‐templated. This method transforms the necklace‐like particulate microstructure of metal oxide aerogels (e.g., Al2O3 Cr2O3, and Fe2O3) into a polymer‐like nanobelt structure. Remarkably, even after removing the polymer template through calcination at 600 °C, the nanobelt structure remains intact. These metal oxide nanobelt (MNB) aerogels exhibit exceptional compressibility while retaining their mesoporous structure. As a demonstration, the resulting Al‐MNB aerogel can withstand compression up to 80% strain without fracturing while preserving its porous nanobelt structure and a high specific surface area of 228 m2 g−1 and a pore volume of 0.7 cm3 g−1 after heat treatment at 1300 °C. This work introduces an innovative strategy for creating a distinctive polymer‐like nanobelt microstructure, paving the way for novel applications of metal oxide aerogels with unique structures and enhanced performance. [ABSTRACT FROM AUTHOR]

In this study, the strain field evolution mechanism of laser-repaired 304 stainless steel /In718 heterogeneous structure was studied using EBSD technique. The results show that the strain concentration in the repaired zone is much smaller than that in the substrate zone. As the laser power increases from 900 W to 1100 W, the strain concentration in the repaired zone and the substrate zone increases significantly. The different strain concentration in the repaired region and the substrate region is mainly related to the increase of lattice distortion, dislocation density and temperature gradient. In addition, because the grains with different orientations have different Taylor factor, and therefore, grain orientation is also key factor affecting the strain concentration. [ABSTRACT FROM AUTHOR]

We developed, mastered and introduced the technology of smelting, dispersion, compacting, deformation processing, heat and adjustment treatment of new powder high-alloy tool steels of the following grades: R3M3F4-MP, R7M7F7K11-MP, R14M3F5K11-MP, 140Kh5M4F4-MP, 110Kh8M2FSС-MP, Kh14MF9-MP, Kh18MF3S-MP, 8Kh8MF3- MP. The quality of sectional metal products of the new powder steels meets the requirements of TU DSS 005-13 and technical protocols. 2 Ref., 2 Tabl., 3 Fig. [ABSTRACT FROM AUTHOR]

The features of formation of the structure, composition and certain mechanical properties of layered materials based on titanium and its alloys during melting by the electron-beam cold-hearth melting technique are considered. The influence of composition in two-layer structures Ti64 (Ti–6Al–4V)/LCB (low-cost beta Ti–1.5Al–6.8Mo– 4.5Fe) and Ti64/Ti5553 (Ti–5Al–5V–5Mo–3Cr), as well as 4-layer Ti5553/Ti64/c.p.Ti (commercial purity titanium)/Ti64 is studied. The processes of formation of transition layers at the boundaries between alloys after both the smelting and the subsequent deformation by rolling, as well as after heat treatments, are studied. A relationship is established between the composition and the formed microstructure, on the one hand, and hardness, strength, ductility, and fracture under 3-point bending, on the other hand. A comparison of the titanium-layered materials produced by this method with the results provided by other technological approaches is carried out, and the advantages of the proposed technology are shown. [ABSTRACT FROM AUTHOR]

Copyright of Metal Working (1674-165X) is the property of Metal Working 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.)

Copyright of Automatisierungstechnik is the property of De Gruyter 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.)

A three-dimensional model of cephalosporin powder particles was constructed, and the interaction between the particles and the surface of the transport tool was simulated. In this paper, the microstructure of the tool surface was prepared by femtosecond laser technology and the effect of different tilt angles on the particle transport characteristics was investigated. The experiments show that the interaction force between the particles and the surface of the transport tool increases with increasing particle size, and the rate of change is 0.00854 μN/μm. The resistance required for particle shedding decreases and then increases as the angle of inclination of the machine increases. At a tilt angle of 30°, the interaction force between the particles and the machine is minimal. At less than 30°, the rate of change of resistance reduction is − 0.06021 μN/°. Above 30°, the rate of change of resistance increase is 0.0414 μN/°. The shedding rate of powder particles was higher on the transversely and longitudinally etched tool surfaces than on the unetched surfaces. This work demonstrates that femtosecond laser microstructures on metal tool surfaces can effectively prevent powder deposition on the tool surface. It provides an experimental basis for improving the metrology accuracy of ultrafine powder materials. [ABSTRACT FROM AUTHOR]

In laminar cooling, the cooling intensity is directly impacted by the heat transfer coefficient and affects the microstructure of metal materials, which in turn affects product performance. In order to determine the laminar cooling heat transfer coefficient, this study suggests a certain approach. Using the nozzle as the center, the dispersal form of coefficient of heat transfer as piecewise function formed a straight line and half sine wave was determined. It lays out the steps to take in experimental data, operating parameters, and structural parameters to get function's characteristic parameters. Experimental results confirm the method's correctness, and the effect of metal-specific characteristics on the temperature field was studied. A solid theoretical foundation for the field production process was provided by the mutual verification of the experimental and computed outcomes. [ABSTRACT FROM AUTHOR]

The main motivation for this study was to improve implant materials. The influence of silver and gold on the structure and mechanical properties of Mg–Nd–Zr alloy was studied. In the work, quantitative and qualitative evaluation of the structural components of magnesium alloy with noble metal additives was performed. The research methods used were investigation of the mechanical properties and observation of micro– and macrostructures. The results showed that modification of magnesium alloy with Ag and Au contributes to the formation of spherical intermetallics of smaller size groups, which become additional centers of crystallization and grind the cast structure. The best composition from additional alloying with silver and gold was determined. Their positive effect on the strength and ductility properties of the metal was established. Preclinical and clinical testing was performed and the prospects for noble metal modification of bioabsorbable magnesium alloy for implant production usage were shown. [ABSTRACT FROM AUTHOR]

TiZrHfAgV0.2 (Ti23.8Zr23.8Hf23.8Ag23.8V4.8, at%) high entropy alloys (HEAs) with a dual bcc structure were developed. Fine lamella structure was observed in the arc-melted ingots and melt-spun ribbons. The TiZrHfAgV0.2 HEAs with a dual bcc phase structure were designed by exploiting the concept of immiscibility of the constituent elements. The immiscibility of the constituent elements in the multi-component alloys was discussed using the mixing enthalpy (ΔHi-j) matrix of the i-j elements, binary phase diagrams with liquid miscibility gap, and the thermodynamic calculations. [ABSTRACT FROM AUTHOR]

The current study investigates the development of a replica molding process for hypervariable microstructures. Initially, the mold deformation theory for these hypervariable microstructures was derived. Based on this theory, a metal material with magnetic properties was selected as the structural material to create a negative Poisson's ratio (NPR) geometric structure. The experimental results, obtained by fabricating the NPR geometric mold layer with a metal material with adjustable magnetic properties and controlling microstructure deformation indirectly, validate the deformation theory and its predictions. These results demonstrate that the developed molding process, integrated with the magnetic NPR regulation system, exhibits excellent stability and replication capability. In this study, at the zero height (z = 0) position on the interface between the NPR geometric structure layer and the Polydimethylsiloxane (PDMS), the variation becomes more pronounced with increasing distance from the center of the microstructure. Furthermore, the tendency of the function curve varies accordingly. The primary cause is the lack of constraints on the free ends of both sides and the excessive constraints on the intermediate parts. Under the conditions in this study, the maximum ratio of its influence on the radial diameter thickness was 2.1%. This innovative process facilitates the rapid imprinting of microstructural components and offers the advantage of efficient molding. [ABSTRACT FROM AUTHOR]

With advancements in the exploration and development of deep and ultra-deep oil and gas resources, the number of ultra-deep wells continues to rise globally. This trend places higher demands on testing technology. The combined perforating and testing technique, an established method for deep and ultra-deep wells, faces challenges. Frequent test operation failures due to perforation detonation failure increase down-hole complexity, restricting the timeliness of testing operations. Current methods use mechanical calibration software to calculate the minimum safety factor of the tubing string for safety assessments. However, without a thorough understanding of perforation detonation failure theory, existing mechanical analysis software remains unreliable for assessing well safety during operations. Simply using the safety factor method lacks reliability and cannot explain the causes of perforation detonation failure. This paper examines an ultra-deep well, referred to as TW1, to analyze perforation detonation failure mechanisms. Through metal microstructure examinations, chemical composition analysis, electron microscope scanning, and numerical simulation, the study yields the following insights: (1) The packer mandrel of Well TW1 fractured due to overstress from the detonation waves. (2) Detonation wave propagation patterns along the tubing string during perforation become apparent. (3) Simulation methods reconstruct the perforation detonation process, calculating effective stress at different tubing string positions over time. (4) It introduces an innovative approach for assessing perforation detonation failure mechanisms through a combination of laboratory testing and simulation modeling. [ABSTRACT FROM AUTHOR]

Doping refractory metal silicates into the matrix of C/SiC composites is an effective means to improve their oxidation resistance. Previous studies have demonstrated that doping HfSiO 4 matrix availably enhanced the oxidation resistance of C/SiC composites, but the high raw material cost of HfSiO 4 limits its widespread application. This paper attempts to introduce ZrSiO 4 matrix, which has lower raw material cost and similar properties to HfSiO 4 , into C/SiC matrix through the same process. To clarify whether the microstructure of the refractory metal silicate doped matrix significantly impacts the oxidation behavior of C/SiC composites, the preparation temperature of ZrSiO 4 was increased to 1100 °C. The densification effect, oxidation behavior, and related mechanisms of C/SiC composites doped with ZrSiO 4 matrix were investigated and compared in detail with the previously studied C/SiC composites doped with HfSiO 4 matrix. Results show that the oxidation resistance behavior of C/SiC composites is relatively sensitive to the microstructure of the refractory metal silicate-doped matrix. At lower preparation temperatures of refractory metal silicates, the particle size of the composite matrix is significantly refined, which is conducive to improving the matrix densification degree of the composites and protecting more carbon fibers from erosion by the oxidizing environment, thus achieving a better oxidation resistance modification effect. [ABSTRACT FROM AUTHOR]

The study object was slag from the Balkhash copper smelter, obtained by re-melting anode mud containing nonferrous metals. The process flow for processing these slags includes sintering with Na2SO4, Na2CO3, and coal, followed by soda-alkaline leaching of the sinter and extraction of metals from the solution into marketable products. Since sintering is the main operation providing high selectivity, the composition of the products of this process was studied. The main transformations during sintering were determined, and the optimal parameters were identified. The structures of slags and sintered materials obtained during the experiments were studied by electron-probe microanalysis. Sintering was performed at 600–800 °C. The best results for sulphidization of slag components were obtained at 800 °C; a further increase in temperature leads to the smelting of sinter particles and slows down sulphidization. The optimal quantities of additives, based on the weight of the slag, are Na2SO4—45%, Na2CO3—15%, and reducing agent—41%, with a sintering time of 2 h. These conditions enable the sulphidization of non-ferrous metals in the slag to the entire depth of the polymetallic globules. The distinct concentration of harmful impurities (Ni, As, and Sb) was observed in the fine structure of the polymetallic globules. [ABSTRACT FROM AUTHOR]

The correlation of welding input heat and microstructure and its impacts on multi-pass mechanical properties in storage tanks alloy steel plate of thickness 6mm using multiple passes SMAW was investigated experimentally and using SOLIDWORKS and ANSYS thermal and Mechanical Simulator. The heat-affected zone (HAZ) dimension was calculated, and the deformation in each pass was also calculated. Optical microscopy was used to characterize the weld metal microstructure effects on joint mechanical properties, the effects of the three pass sequences in deformation, and the resulting alterations in weld metal microstructure. In addition, the impact of this alteration in corrosion resistance characteristics was investigated, and steel samples were simulated. The investigation results illustrated increasing the weldment deformation with increasing heat inputs in the three-pass sequence. The welding joint microstructure shows a big difference in M-A (martensite-austenite) phase formation between the first, second, and third pass microstructure. In addition, the microstructure examinations showed the formation of AF (acicular ferrite) in the third pass, with a higher percentage in the second and first pass. This research demonstrated scientific information about the expected deformation of each pass from the three welding joints, the alteration in microstructures, and the corrosion resistance of the weldment according to the alteration with welding heat input. [ABSTRACT FROM AUTHOR]

This study investigates the microstructure and first hydrogenation properties of Fe52Ti40Zr3V5 and Fe37Ti44Zr9V10 alloys, which are individual phases present in the as-cast TiFe + 12 wt.% ZrV2 alloy (parent alloy). The parent alloy exhibited fast first hydrogenation kinetics due to the interplay of these two phases. Our objective is to study the hydrogen storage behavior of these individual phases. The samples were synthesized by arc melting and characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. The results show that when these alloys are melted separately, they do not exhibit the same phase composition as in the parent alloy, indicating a metastable state under our synthesis conditions, which significantly impacts their hydrogen storage behavior. Hydrogenation capacity was measured using a homemade Sieverts apparatus. Both alloys demonstrated excellent first hydrogenation kinetics, with an absorption capacity of 0.9 wt.% for the Fe52Ti40Zr3V5 alloy and 2.3 wt.% for Fe37Ti44Zr9V10 alloy. Our key finding is that the final crystal structure of multi-element alloys is highly dependent on the synthesis method. [ABSTRACT FROM AUTHOR]

A terahertz metamaterial microfluidic sensing chip for ultrasensitive detection is proposed to investigate the response of substances to terahertz radiation in liquid environments and enhance the molecular fingerprinting of trace substances. The structure consists of a cover layer, a metal microstructure, a microfluidic channel, a metal reflective layer, and a buffer layer from top to bottom, respectively. The simulation results show that there are three obvious resonance absorption peaks in the range of 1.5–3.0 THz and the absorption intensities are all above 90%. Among them, the absorption intensity at M1 = 1.971 THz is 99.99%, which is close to the perfect absorption, and its refractive index sensitivity and Q-factor are 859 GHz/RIU and 23, respectively, showing excellent sensing characteristics. In addition, impedance matching and equivalent circuit theory are introduced in this paper to further analyze the physical mechanism of the sensor. Finally, we perform numerical simulations using refractive index data of normal and cancer cells, and the results show that the sensor can distinguish different types of cells well. The chip can reduce the sample pretreatment time as well as enhance the interaction between terahertz waves and matter, which can be used for early disease screening and food quality and safety detection in the future. [ABSTRACT FROM AUTHOR]

The object of this research is the horizontal centrifugal casting process of the Al6061 alloy. Usually, cast products experience some casting defects, so the horizontal centrifugal casting process is applied to reduce the possibility of casting defects arising. In some casting processes, especially in the production of cylindrical specimens, casting defects such as porosity are encountered. Therefore, horizontal centrifugal casting was applied to overcome this problem. The test results show that the average hardness value for aluminum 6061 specimens resulting from centrifugal casting products with water cooling was 73.3 HRE, while the average hardness value for aluminum 6061 specimens resulting from centrifugal casting products without water cooling was 86.4 HRE. The microstructure results show that the grain size of centrifugal casting products with water cooling was 82.5 µm, whereas without water cooling it was 75 µm. Higher hardness values were obtained in specimens without mold cooling, this is because the conductivity in molds without cooling was higher compared to molds that experienced water cooling. The higher the heat conductivity of the mold, the faster the cooling process of the cast product. The casting process using the horizontal centrifugal method can be carried out to produce cylindrical spare parts. [ABSTRACT FROM AUTHOR]

This study explores the impact of different pre-temper conditions of the base metal (BM) on the microstructure and strength-ductility performance of AA7075 welded joints, aiming to identify effective processing approaches for aluminum alloy forming. The findings reveal that in comparison to the average grain size (AGS) in the weld nugget zone (NZ) of the AA7075-T6 joint (approximately 2.85 µm), the grain refinement is more pronounced in the NZ of the AA7075-O joint (approximately 2.09 µm). Concerning mechanical performance, the AA7075-T6 joint experiences softening in the welding region, demonstrating significantly lower tensile properties than the BM, with an ultimate tensile strength of 416 MPa and an elongation of 4.4 %. Conversely, the AA7075-O joint undergoes hardening in the welding region, displaying higher tensile strength than the BM, with an elongation of 8.7 %. Three-point bending destructive experiments results indicate that the AA7075-O joint can withstand larger bending angles, displaying more thorough plastic deformation and superior forming performance. [ABSTRACT FROM AUTHOR]

To achieve the necessary mechanical properties and high corrosion resistance, heat treatment is based on a significant alteration in the microstructure of metals and alloys. The metal is heated above a critical temperature during heat treatment processes. Several methods, such as quenching and cooling in various media, followed by tempering and other heat treatment operations, can be used to achieve this. Steel can be made more malleable by annealing, which also increases ductility and improves corrosion resistance. In this study, thirty medium carbon steel specimens were used, which were split into different groups, various heat treatments were applied. First quenching, first tempering, second quenching, and second tempering were among the heat treatment procedures used, and cooling media made of distilled water were used at various temperatures. After that, the corrosion rate in these specimens was looked at, and the results were compared to the corrosion rate in the base specimen. The results show that repeated heat treatment of the metal generally lowers the rate of corrosion in the metal, particularly when distilled water is used for the cooling process after the two tempering stages at a temperature of almost absolute zero. The findings show that the second sample had the lowest corrosion rate of all the samples. When compared to the corrosion rate in the basic sample, the corrosion rate in this sample decreased by about 92.9%. [ABSTRACT FROM AUTHOR]

This paper presents the synthesis and characterization of Al-0.35Cu-0.18Sc-0.06Zr alloys, possessing remarkable electrical and mechanical properties. Specifically, the electrical conductivity and tensile strength of this alloy are reported to reach 60.4%IACS and 169.46 MPa, respectively. The electrical conductivity combined with Wiedemann–Franz law was calculated for Al-0.35Cu-0.18Sc-0.06Zr alloys thermal conductivity as showing excellent thermal conductivity. Microscopic analysis shows that a large number of fine "bean-petal" shaped Al3(Sc, Zr) particles, i.e., the second phase, were diffusely distributed in the alloy. These particles are highly cohered with the matrix, resulting in small and shallow toughness dimples at the tensile fracture. Due to the low diffusion coefficient of Zr element, the growth rate of precipitated second phase particles can be effectively reduced, which leads to forming Al3(Sc, Zr) phase with Zr-rich shell and improving the intrinsic coarsening property of Al3Sc phase. The Al3(Sc, Zr) second phase exhibits a large surrounding strain of approximately 2.5%, resulting in a significant elastic strain field that inhibits dislocation movement, thereby increasing alloy strength. Furthermore, the heat resistance test results show that the alloy can operate steadily at 503 K for up to 350, 400 h. [ABSTRACT FROM AUTHOR]

Corrosion inhibitors are one of the best practices to prevent the far-reaching negative impacts of corrosion on ferrous alloys. A thorough understanding of their corrosion-inhibiting effects is essential for a sustainable economy and environment. Anionic surfactants are known to act efficiently as corrosion inhibitors. Here, we present that in-situ atomic force microscopy (AFM) measurements can provide deep insights into the adsorption and inhibition mechanism of surfactants on stainless steel surfaces during local corrosion. These include the configuration of surfactant molecules on the surface and how the microstructure of the stainless steel surface influences the inhibition process. Three different anionic surfactants, namely palm kernel oil (PKO), linear alkylbenzene sulfonate (LAS), and fatty alcohol ether sulfate (FAES), were investigated on a titanium-stabilized ferritic stainless steel (1.4510) in NaCl solution. For PKO, the results show random adsorption of bi- and multilayer whereas LAS and FAES adsorb only as local corrosion occurs. Thereby, LAS accumulates only locally and especially at the titanium precipitates of the 1.4510 and FAES forms a densely packed monolayer on the surface. This leads to better corrosion inhibiting properties for LAS and FAES compared to PKO. [ABSTRACT FROM AUTHOR]

Electrochemical discharge machining (ECDM) micro-milling exhibits enormous machining potential in manufacturing metal microstructures. In this paper, a novel sinking ECDM micro-milling using glycol-based electrolyte is proposed for the high-quality fabrication of metal micro-channel structures. Firstly, a novel combined process is developed for the simple and efficient preparation of micro-electrode. With the proposed method, a micro-electrode with 91.1 μm in diameter and 21.2:1 in aspect ratio is successfully machined in 47.2 minutes. Secondly, experimental research on ECDM micro-milling machining of micro-channels in glycol-based electrolyte is carried out using the fabricated micro-electrode. Experimental results show that the machined voltage significantly affects the machining quality of micro-channels. Wear analysis reveals that the bottom geometry of the micro-electrode exhibits equal wear along the axis direction with processing times increasing, and a constant length compensation strategy (1.52 μm/mm) is adopted. Finally, an S-shaped micro-channel without recast layers (Ra 0.093 μm) was successfully fabricated. [ABSTRACT FROM AUTHOR]

The inoculation of nano-sized particles of refractory Al2O3, TiO2, MgO, ZrO2 oxides into the welding bath was studied. The inoculation of oxides with a low-level mismatch to the δ-Fe lattice and increased wetting with liquid iron (MgO, ZrO2) contributes to the growth of dendrites, which are formed during melt crystallization. Metal modification with MgO, ZrO2 oxides decreases the hardness of polygonal ferrite and increases the content of lower bainite in the microstructure of joints, brittle fracture resistance of the joint metal. Metal modification with Al2O3, TiO2 oxides contributes to an increase in the hardness of polygonal ferrite, the content of upper bainite in the joint microstructure, and the strength of welded joints of low-alloy steels. [ABSTRACT FROM AUTHOR]

Rational morphology control of inorganic microarchitectures is important in diverse fields, requiring precise regulation of nucleation and growth processes. While wet chemical methods have achieved success regarding the shape‐controlled synthesis of micro/nanostructures, accurately controlling the growth behavior in real time remains challenging. Comparatively, the electrodeposition technique can immediately control the growth behavior by tuning the overpotential, whereas it is rarely used to design complex microarchitectures. Here, the electrochemical design of complex Cu2O microarchitectures step‐by‐step by precisely controlling the growth behavior is demonstrated. The growth modes can be switched between the thermodynamic and kinetic modes by varying the overpotential. Cl− ions preferably adhered to {100} facets to modulate growth rates of these facets is proved. The discovered growth modes to prepare Cu2O microarchitectures composed of multiple building units inaccessible with existing methods are employed. Polyvinyl alcohol (PVA) additives can guarantee all pre‐electrodeposits simultaneously evolve into uniform microarchitectures, instead of forming undesired microstructures on bare electrode surfaces in following electrodeposition processes is discovered. The designed Cu2O microarchitectures can be converted into noble metal microstructures with shapes unchanged, which can be used as surface‐enhanced Raman scattering substrates. An electrochemical avenue toward rational design of complex inorganic microarchitectures is opened up. [ABSTRACT FROM AUTHOR]

Samples of alloy 601, 602 CA and 602 MCA with different thickness and microstructure, all 600 grit laboratory ground, are compared. All samples are exposed to up to 5693 h at 600°C in a metal dusting producing atmosphere with a total pressure of 20 bar. A smaller sample thickness leads to an increased pit density for alloy 601 and an increased pit density, a longer incubation time and an increased pit depth growth rate for alloy 602 CA. This is attributed to lower stresses in the scale of the thinner samples. Grain size effects of the substrate are probably concealed by the deformed and recrystallized subsurface due to the 600 grit finish of the samples. If carbides are unavoidable in an alloy, they should be small, as they can serve as chromium suppliers during scale formation better than larger ones. They increase incubation time and pit depth growth rate. [ABSTRACT FROM AUTHOR]

The structure of the base metal and weld metal after electron-beam welding (EBW) of the intermetallic titanium alloy Ti−28Al−7Nb−2Mo−2Cr (wt.%) obtained by the electron-beam melting method is studied. The macrostructure of the Ti−28Al−7Nb−2Mo−2Cr alloy ingot is characterized by grains close to equiaxed with a grain size of 8–9 points. As shown, the microstructure of the cast metal of the Ti−28Al−7Nb−2Mo−2Cr alloy consists of a matrix bright γ-phase alternating with sections of a two-phase (γ + α2) lamellar structure up to 50 µm in size, with a lamellae thickness of about 1 µm, and of the ordered β-phase, which forms a mesh pattern against the background of the matrix. As established, the intragranular structure of the metal of the welded joint after EBW with local heat treatment (LHT) differs from the structure of the base metal and consists of small (up to 20 µm) areas with a (γ + α2) lamellar structure against the background of a light matrix γ-phase with a network of elongated particles of 30−80 µm long and 1−3 µm thick. [ABSTRACT FROM AUTHOR]

The derivatives of metal–organic frameworks have been proven to be ideal candidates for microwave absorption due to their ability to form diverse microstructures of metals/heteroatom doped-carbon composites. In this study, we synthesized three types of zinc oxide (ZnO)@ZIF-8 with varying ZIF-8 shell thicknesses using ZnO colloidal spheres as sacrificial templates. Subsequently, we investigated the microwave absorption properties of a series of non-magnetic ZnO/N-doped carbon nanospheres pyrolyzed by ZnO@ZIF-8 at different temperatures. Remarkably, the non-magnetic samples (30 wt% filler loading) with a hollow structure pyrolyzed at 800 °C exhibited a broad effective absorption band exceeding 6 GHz. The excellent microwave absorbing performance of the samples pyrolyzed at 800 °C can be attributed to the reduction of the ZnO core to Zn0, anchoring it in the graphitized N-carbon layer, and the formation of an inner hollow cavity that enhances impedance matching. Therefore, this research not only provides an array of excellent dielectric-type microwave absorbing materials but also presents a novel strategy for developing lightweight and high-performance non-magnetic carbon-based microwave absorbing materials. [ABSTRACT FROM AUTHOR]

To satisfy the needs of precision machining, ultrafine tungsten carbide (WC)-based cemented carbide with fine grain size and excellent mechanical properties was prepared. Ultrafine cemented carbide was prepared by spark plasma sintering (SPS) using WC, Co as raw materials and metal elements V, and Cr as additives, and the effects of metal elements on the microstructure and mechanical properties of cemented carbide were investigated. The results show that the specimen (91.6WC-1.2V-1.2Cr-6Co) prepared at 1350 °C, 6 min, 25 MPa has the best mechanical properties (HV 2322.9, KIC 8.7 MPa·m1/2) and homogeneous microstructure. The metal elements could react with WC to form a (W, V, Cr) Cx segregation layer, which effectively inhibits the growth of WC grains (300 nm). The combination of SPS and metal element additives provides a new approach for the preparation of ultrafine cemented carbides with excellent properties. [ABSTRACT FROM AUTHOR]

Brazing of hot work steel with nickel‐based filler metals is a widely used process for manufacturing casting tools. However, the formation of brittle phases in the joint impairs its mechanical properties. Reducing these intermetallic phases is an important aspect. Thermodynamic equilibrium calculations are used to estimate the change in melting range and apearance of intermetallic phases by adding different amounts of molybdenum to Ni 620. The filler metals are then produced and their solidus and liquidus temperatures are investigated using differential scanning calorimetry. Specimens of X37CrMoV5‐1 are then brazed in a vacuum furnace and their microstructure is analysed by scanning electron microscopy/electron dispersive spectroscopy and their hardness properties by nanoindentation. The addition of molybdenum to the Ni 620 filler metal leads to the formation of chromium molybdenum boride rich phases and reduced hardness values in brazed joints. Manipulation of Ni 620 by molybdenum helps to improve relevant properties in brazing hot work steel. [ABSTRACT FROM AUTHOR]

When fabricating a metal powder filter with a double-layered pore structure, which includes a microporous layer, by coating flake-shaped powder using the Wet Powder Spray (WPS) process, it is crucial to ensure that the coating is applied parallel to the surface of the metal powder filter. Failure to do so can result in a non-uniform pore structure, leading to a rapid decline in particle filtration efficiency. Therefore, it is necessary to improve the alignment of the coated flake-shaped powder on the filter surface. In this study, a metal powder filter with a double-layered pore structure was fabricated by applying a flake-shaped metal powder coating to a tube-shaped SUS316L powder filter using the WPS process. In order to improve the flake-shaped powder orientation of coating layer, the impact of the rolling process was investigated. The characteristics of the pores were analyzed based on the powder size and the rolling time. The microstructure of the fabricated metal powder filter was observed using an optical microscope, surface roughness, variations in thickness, and air permeability were analysed. [ABSTRACT FROM AUTHOR]

It has been a common method to improve the mechanical properties of metals by manipulating their microstructures via static recrystallization, i.e., through heat treatment. Therefore, the knowledge of recrystallization and grain growth is critical to the success of the technique. In the present work, by using in-situ high temperature EBSD, the mechanisms that control recrystallization and grain growth of an extruded pure Mg were studied. The experimental results revealed that the grains of priority for dynamic recrystallization exhibit fading competitiveness under static recrystallization. It is also found that grain boundary movement or grain growth is likely to show an inverse energy gradient effect, i.e., low energy grains tend to swallow or grow into high energy grains, and grain boundaries of close to 30° exhibit superior growth advantage to others. Another finding is that {10–12} tensile twin boundaries are sites of hardly observed for recrystallization, and are finally swallowed by adjacent recrystallized grains. The above findings may give comprehensive insights of static recrystallization and grain growth of Mg, and may guide the design of advanced materials processing in microstructural engineering. [ABSTRACT FROM AUTHOR]

This document is a summary of two journal articles in the field of materials science. The first article discusses the importance of microstructure design in achieving desired material properties, with a focus on metals and alloys in aeronautical and aerospace applications. It includes a list of related articles covering topics such as welding and phase transformation. The second article is a compilation of various research studies in materials science, covering topics such as the effects of boron additions on alloy microstructure and the properties of porous alloys. Both articles provide valuable insights into the behavior and properties of different materials. The document acknowledges the contributions of the authors and reviewers and expresses gratitude to the publisher, MDPI. [Extracted from the article]

The 2A50 aluminum alloy micro inner gear rings were fabricated using a rheological extrusion process. Metal flowing and microstructure characteristics of the micro inner gear rings in rheological extrusion were investigated by finite element simulation and experiments, respectively. The microstructures of the tooth, bottom land, and non-dentiform region were considered as representative sections of the inner gear ring. Results reveal that during the rheological extrusion process, the metal exhibited a continuous flow from the periphery toward the center of the billet along the radial direction, meticulously filling the tooth spaces of the mandrel. Concurrently, a gradual decline in flow velocity was observed. The grains in the teeth and bottom lands were fine and elongated along the flowing lines, whereas those in the non-dentiform region were similar to the semi-solid slurry with nearly equiaxed grains. The microstructure of the micro inner gear rings predominantly consisted of recrystallized grains and substructures. In non-dentiform regions, the proportion of recrystallized grains was remarkably higher than that of the substructure. The average grain size of the microstructure of the inner gear ring ranged between 14.04 and 20.05 μm. The grain size in the tooth was sensitive to the extruded temperature and showed an increment of approximately 36.3% when the temperature increased from 575 °C to 590 °C. This phenomenon suggests that low temperature in the semi-solid range was advantageous for the microstructure and mechanical performance of the inner gear ring. No pronounced texture was detected in the micro inner gear rings, and the peak intensity (4.81) in the pole figures was found in the bottom land at the extruded temperature of 590 °C, suggesting a relatively weak {112} < 126 > texture. This process recommends a propitious technique for the fabrication of components with microfeatures. [ABSTRACT FROM AUTHOR]

Ni anisotropic microgroove structures were prepared by lithographic processes and electroforming to investigate the effect of microstructures on friction forces. For Ni microgroove structures, the friction forces varied significantly depending on the indenter sliding direction to the anisotropic microstructures. The friction forces of parallel sliding directions on microgroove structures were unstable and considerably larger than those of the perpendicular directions owing to the difference in the structure continuousness. These results suggest that anisotropic microstructures affect friction forces and can deploy fail-safe functions when a large load is accidentally applied. [ABSTRACT FROM AUTHOR]

Cathodic protection is widely used for metal corrosion protection. To improve their performance, it is necessary and urgent to study the influence of metal oxides on the microstructure and performance of aluminum alloy sacrificial anodes. Taking an Al-Ga-In sacrificial anode as the research object, the dissolution morphology and current efficiency characteristics were studied by means of electrochemical testing and microstructural observation, and the influence of varying Pb and Bi contents on the performance of an aluminum alloy sacrificial anode was investigated. The test results reveal that: (1) The Al-Ga-In sacrificial anode with 4% Pb and 1% Bi contents exhibits the best sacrificial anode performance. (2) The inclusion of an appropriate Bi element content shifts the open-circuit potential in a negative direction and promotes activation dissolution. Conversely, excessive Bi content leads to uneven dissolution, resulting in the shedding of anode grains and greatly reducing the current efficiency. (3) During the activation dissolution of the aluminum alloy, the second phase preferentially dissolves, and the activation point destroys the oxide film, resulting in the dissolution of the exposed aluminum matrix. Consequently, the concentration of dissolved metal ions is reduced and deposited back on the surface of the anode sample, promoting the continuous dissolution of the anode. [ABSTRACT FROM AUTHOR]

To address the issue of liquid metal embrittlement (LME) susceptibility in galvanized 22MnB5 steel during the hot stamping process, the material's performance is affected. This study proposes a method combining precooling and tube hydroforging to produce galvanized tubular hot stamping parts. The primary workflow comprises four distinct stages: the heating phase, thermal retention phase, precooling phase, and the tube hydroforging phase. Notably, the precooling stage employs two distinct approaches: air precooling and boiling water precooling. The composition and morphology of the zinc coating and the microstructure and mechanical properties of the 22MnB5 steel are investigated using two precooling methods at different hydroforging temperatures. The results show that when the initial hydroforging temperature is below 800 °C, the precooling combined with the tube hydroforging process eliminates LME. With increasing precooling time, the oxidation reaction forms ZnO and Fe2O3 on the coating. By comparing the composition, morphology, and mechanical properties of the coatings at hydroforging temperatures of 800 °C and 500 °C, it is concluded that the boiling water precooling aligns more effectively with the requirements of industrial production, with the optimal forming temperature being within the range of 750–800 °C. [ABSTRACT FROM AUTHOR]