W-Cu composites is a structural and functional integrated material composed of W and Cu, exhibiting exceptional properties such as high hardness, strength, thermal stability, wear resistance, low coefficient of thermal expansion, good ablative resistance and conductivity. It finds extensive applications in electronic, electrical, aerospace and military industries. However, commercial W-Cu composites prepared through high temperature infiltration or liquid phase sintering often possess coarse structures with inferior mechanical properties. As China's industrial modernization progresses rapidly, higher requirements are also put forward for the comprehensive properties of W-Cu composites. As a result, the preparation technology of W-Cu powder and blocks has greatly accelerated the development of W-Cu composites in recent years. This review summarizes the mechanisms and characteristics of different forming technologies and powder preparation techniques for W-Cu composites, along with an analysis of their microstructure and properties. Finally, future trends for the development of W-Cu composites are discussed.

Rare-earth permanent magnet radiation-oriented integral magnetic rings are a crucial type of permanent magnet material, widely utilized in high-end electromechanical products, precision measuring instruments, and advanced defense technologies, among other fields. The advancement of radial integral permanent magnet ring preparation technology is of significant importance for promoting the leapfrog development of China's advanced equipment. This article introduces the classification and characteristics of rare earth integral permanent magnetic rings from three aspects: magnetic ring materials, preparation processes, and orientation methods. It focuses on the current research progress of the radial forming process and mechanical properties of sintered rare earth radial integral permanent magnetic rings. These advancements provide new ideas for the development of high-performance sintered rare earth radial ring technology.

The coercivity of sintered Nd-Fe-B magnets can be improved and the cost can be reduced when light rare earth is used as the diffusion source to replace part of heavy rare earth. In this paper, the heavy rare earth Tb in Tb-Al-Ga alloy was partially replaced by low-cost light rare earth Pr. The effects of Pr substitution on the magnetic properties and microstructure of sintered dual-main-phase Nd-Ce-Fe-B magnets and sintered singlemain-phase Nd-Fe-B magnets were studied, and the coercivity strengthening mechanism was revealed. With Pr60Tb20Al10Ga10 as the diffusion source, the coercivity of the grain boundary diffusion magnet increases obviously. Compared with the single main phase magnet, the diffusion depth of the double main phase magnet is significantly increased. Pr with low melting point preferentially enters the magnet and improves the wettability of grain boundary phase. This causes more Tb elements to enter more deeply in magnet, forming a shell structure with high magneto-crystalline anisotropy field surrounding main phase grain, and then improving the coercivity of GBDed magnet.

Nb-16Si-10Mo and Nb-16Si-10Mo-10Ti alloys were prepared by Spark Plasma Sintering (SPS) technique. The effect of sintering temperature on the microstructure and properties of the two alloys was analyzed . The results show that Nb-16Si-10Mo alloy is composed of three phases: Nbss, Nb3Si and Nb5Si3, while Nb-16Si10Mo-10Ti alloy is composed of three phases: Nbss, Nb5Si3 and Tiss, and the densities of both alloys are above 99.4%. With the increase of sintering temperature, the Vickers hardness and compressive strength of the two alloys first increase and then decrease, while the bending strength and fracture toughness gradually decrease. With the addition of Ti element, the fracture morphology appears dimple characteristics, and the fracture mode changes from brittle fracture to composite fracture, and the Vickers hardness and compressive strength of the alloy are reduced at various sintering temperatures, while the bending strength and fracture toughness are increased.

Sintered metal porous materials are a special type of metal material that integrates structure and function. They are widely used in industries such as coal chemical, petrochemical, aerospace, new energy, semiconductor, smelting, and environmental protection, and play an important role in the development of the national economy This paper introduces the types of sintered metal porous materials and elaborates on their applications in filtration and separation, fluid distribution control, catalytic loading, and enhanced mass and heat transfer. It predicts the development trend of sintered metal porous materials, which will continue to develop towards material composite, pore size refinement, structural gradient, widespread application, and multifunctionality in the future.

Powder metallurgy technology is a scientific technology manufacturing metal powders, alloy powders, non-metallic powders, compound powders, or materials or products made from these powders through forming and sintering. As the metal powder in the preparation process is easy to adsorb oxygen and oxidation, in the sintering process is not easy to fully deoxidise, and with the development and use of alloying elements, chemically active alloying elements are easy to combine with oxygen elements, increasing the difficulty of deoxidisation, so that powder metallurgy materials are prone to oxygen content exceeding the standard, which seriously affects the performance of powder metallurgy materials. This paper discusses the influence of oxygen content on the preparation process and mechanical properties of various metals and alloys, and introduces the methods of controlling the oxygen content of some metals in the powder metallurgy process. It focuses on the research progress of oxygen content control of iron-based powder metallurgical materials, titanium and titanium alloy powder metallurgical materials, copper alloys, refractory metal tungsten and molybdenum powder metallurgical materials, and summarises the current status of the research and looks forward to the development trend of its future.

Ti/ZrO2-Al2O3 gradient material was prepared by laser directed energy deposition technology. The microstructure, element distribution and changes of microhardness were systematically analyzed by means of scanning electron microscopy, energy spectrometer and Vickers hardness tester, and the influence of Al2O3 con‐ tent in ZrO2 ceramic powder on the microstructure and properties of the material was explored. The results show that with the increase of Al2O3 content, the mixing of the two phases is more uniform, while the cracking phenom‐ enon is more serious at the interface. The hardness of ceramic region in the sample also increases as the Al2O3 content increases. When the Al2O3 content is 30%, the hardness reaches 1344.5HV0.2, but in the binding region, the hardness increases significantly, reaching 1187.3HV0.2, only when the Al2O3 content increases to 30%.

Laser powder bed fusion (LPBF) exhibits significant advantages in the manufacturing of high-entropy alloys (HEAs) with complex shapes and good strength-toughness properties. To further enhance the mechanical strength of HEAs, adding Nb element is an effective way which could enhance the solid solution strengthening and second phase strengthening effects. However, the structure features of second phase formed during LPBF is prone to brittle fracture, resulting in the significant decrease in the toughness properties of HEAs. Therefore, it is of great significance to study the effect of heat treatment post-processing on the microstructure and properties of HEAs fabricated by LPBF. The CoCrFeMnNiNb_0.15 HEAs were successfully prepared by LPBF first, and then the evolution of phase structure, mechanical properties and fracture morphology were studied after heat treatment. The results show that the heat treatment prompts the structure transformation of Nb-rich Laves phase from the continuous network to the fine and dispersively-distributed particles, and partial Nb element precipitates from the matrix structure of the FCC phase. Besides, the matrix grains also grow up along the (111) crystal orientation. With the increase of heat treatment temperature, the Laves phase and the matrix structure become coarsened gradually. Due to the weakened solid solution strengthening, grain boundary strengthening and second phase strengthening effects after heat treatment, the plastic deformation capability of the FCC phase is improved, thus resulting in the failure mode changed from brittle fracture to ductile fracture. When the heat treatment temperature is 980 ℃, the CoCrFeMnNiNb_0.15 HEAs can obtain the well-matched strength-toughness properties, which shows the product of strength and elongation of 13.2 GPa%, ultimate tensile strength of (892 ± 13.4) MPa, and elongation rate of 17.4%.

TWIP steel controls stacking-fault energy to create twinned crystal organizations, enhancing ductility and strength. Although extensive research has been conducted on TWIP steels fabricated by melting, limited attention has been given to TWIP steels prepared through powder metallurgy. Furthermore, the current powder metallurgy TWIP steel samples have not fully realized their vast application potential. The materials were prepared at different temperatures and times using a combination of gas-atomized Fe-21Mn-0.7C alloy powder and fast hot pressing technology. The effects of sintering temperature and sintering time on the tissue evolution and mechanical properties of the materials and subsequent hot rolling and heat treatment to further optimize the comprehensive mechanical properties were investigated. The results show that the temperature increases, the holding time increases, the small particle size range powders are fully fused together to form a denser structure, and the grain boundary oxides have basically been depinned. At 930 °C, 40 MPa, and 12 minutes, the alloy achieves a density of 98.86%, tensile strength of 955 MPa, and extensibility of 32.8%. After hot rolling, the tensile strength can reach 1 690 MPa. After annealing, a high-strength and high-toughness steel with excellent comprehensive mechanical properties is obtained, with the tensile strength and elongation being 998 MPa and 46.2% respectively. The annealed material exhibited excellent comprehensive mechanical properties.

Laser cladding was carried out to prepare Ni₃Al/Cr₇C₃ alloy coatings on 42CrMo steel. The effects of different Cr₇C₃ contents on the microstructure and wear resistance of the cladding materials were investigated using scanning electron microscopy, X-ray diffraction and wear tribometer. The results indicate that the microstructure of the Ni₃Al based cladding materials contains mainly Ni₃Al and in situ-formed Cr₇C₃. The microhardness of the laser cladding materials prepared by Ni₃Al/Cr₇C₃ alloy powder is above 550HV, and the maximum reaches 834HV. With the increase of Cr₇C₃ content, the wear resistance of Ni₃Al based cladding materials first increases and then decreases. When the Cr₇C₃ content is 25%, the wear rate of Ni₃Al based cladding materials is 0.74×10^-5 mm³/(N·m), only 14.7% of the wear rate of Ni₃Al laser cladding coating without Cr₇C₃, and the wear rate of Ni₃Al-based alloy cladding materials is only 1.669×10^-5 mm³/(N·m).

In response to the application requirements of tungsten-impregnated copper material in high-tempera‐ ture gas erosion, the tungsten- infiltrated copper material (W-7Cu) experienced high-temperature gas erosion was analyzed. The focus was on the morphological features of the similar nut-shaped that appeared on the surface of W-7Cu after burning.The microstructure was observed by SEM and metallographic analysis. The loss of copper was estimated through energy spectrum. The phase structure changes was analyzed by XRD. The results show that Cu loss occurres in everywhere of the materials, and C is presented on both the outer and inner surfaces. Both of the inner and outer surfaces contain a large amount of W6C2.54 and WC phases. Under high temperature and high-speed particle flow, the C particles enters the W skeleton formed after Cu precipitating and reacts with W to form new low-melting phases, which induces the ablation accelerating.

Selective laser melting (SLM) technology has attracted much attention from the aeronautics and astronautics realm due to its advantage of high degree of freedom, high accuracy, and good mechanical properties after printing. Considering the durability and designing concept of damage tolerance of structural materials, the crack propagation rate of components applied into aeronautics is regarded as one of the key points to ensure the service safety of equipment. The research of ameliorating the crack resistance of titanium alloys through posttreatment is believed to provide valuable data guidance to the further application of SLM-printed titanium-based components in the aeronautics. In the current paper, the hot isostatic pressing (HIP) process is conducted to SLM-printed TA15 alloys as the post-treatment. Specifically, the influence of the HIP temperature on the microstructure, hardness, and crack propagation rate are investigated in details. The microstructure of the as-printed TA15 alloy HIP treated at the temperature range of 900-980 ℃ is generally identified as multi-hierarchical needle or lath-like α phase. Besides, the size of the α phase gradually coarsens along with the rise of the HIP temperature. The average length of primary α phase ranges from 60 μm to 66 μm. Whereas, the width of primary αphase significantly increases from 2.35 μm to 5.62 μm. The hardness of the HIPed specimen resultantly reduces from 35.8 to 31.9 (HRC). When the HIP temperature surpasses the phase transformation point of α to β phase, the formation of Widmannstatten structure is observed in the specimen with hardness of 32.2 (HRC). The crack propagation rate of the specimens HIP treated utilizing different parameters converges and is seldomly affected by the microstructure when the stress intensity factor range (ΔK) is within 20~50 MPa·m1/2. While the crack propagation rate gradually decreases with the rise of HIP temperature when ΔK＜20 MPa·m1/2. Coarsening of multi-hierarchical needle(lath)-like α phase enhances the deflection of crack propagation path caused by microstructure, which correspondingly retards the further propagation of cracks. Widmannstatten structure formed in the specimen HIP treated at 1 020 ℃ possesses the lowest crack propagation rate among different microstructures. In addition, the packets of α phase with various crystallographic orientation inside the β phase favors the conversion of fatigue cracks propagation path, which effectively lengthens the propagation path and reduces the crack propagation rate. In summary, the coarsened multi-hierarchical lath-like α phase in the specimen HIP treated at 980 ℃ and the Widmannstatten structure formed after HIP treatment at 1 020 ℃ benefit to the reduction of crack propagation rate. While the hardness of specimens suffers a certain loss.

In order to study the influence of Nb elements on the organization and properties of FeCoCrNiMn high-entropy alloy, FeCoCrNiMnNb high-entropy alloy coatings were prepared on the surface of Q235 steel by using laser cladding technology, and the phase compositions, microstructures, elemental distributions, nano-hardnesses and wear behaviors of the coatings were investigated, respectively. The results show that the FeCoCrNiMnNb high-entropy alloy coating consists of FCC phase and Laves phase. Among them, the matrix phase is the FCC phase and the bar organization is the Laves phase. Due to the solid solution strengthening and the second precipitation strengthening effect, the nanohardness of the FeCoCrNiMnNb high-entropy alloy coating is significantly enhanced to about 9.193 GPa, which is about twice of that of the FeCoCrNiMn coating. Due to the significant enhancement of the nanohardness, the FeCoCrNiMnNb coating has excellent wear resistance, with a wear rate of 2.549×10-5 mm3/N·m, which is about 0.33 times that of the FeCoCrNiMn coating. The wear mechanism of the FeCoCrNiMnNb coating is a single abrasive wear. In summary, the FeCoCrNiMnNb high-entropy alloy coating has very high nanohardness and excellent wear resistance

TC4 titanium alloys with high density, fine grain and excellent tensile properties were prepared by hot pressing (HP) sintering technique. The effects of HP sintering temperatures (880, 930, 980 ℃) on the microstructure and tensile properties of TC4 titanium alloy samples were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), room temperature tensile tests, etc. The results show that the HPed TC4 samples consist mainly of equiaxed α phase and intergranular β phase. With the increase of hot pressing temperature, the grain coarsens, and the volume fraction of the α phase decreases. When HP temperature is 930 ℃, the tensile properties of the alloy sample are the best at room temperature, and the maximum tensile strength and elongation after fracture are 934 MPa and 26.3%, respectively, which is better than the cast and hot isostatic pressing TC4 titanium alloys reported in the relevant literature.

Cu/Al laminated composites are more and more widely used because of their high cost-effective synergistic effect. However, the interface structure, microstructure of copper layer and aluminum layer of Cu/Al composites prepared by different process methods are different, and the mechanical properties are different. The difference in interface bonding characteristics leads to macroscopic quality problems such as dislocation, delamination, and copper layer surface tearing during deep processing, which seriously restricts its application in high-end fields. In this paper, the research status of atomic scale of copper-aluminum laminated composites is introduced. The research progress of molecular dynamics simulation on the interface layer structure, diffusion and solidification, the correlation between heterogeneous interface characteristics and mechanical properties of copper-aluminum laminated composites is reviewed. The advantages and disadvantages of different potential functions in molecular dynamics simulation of copper-aluminum laminated composites are analyzed. It is proposed that accurate model, reasonable force field and accurate parameters are the three basic criteria for material atomic scale simulation, which provides a reference for the study of atomic scale of metal laminated composites.

Mg10Ni-X alloys (X=MWCNTs, TiF3, MWCNTs-TiF3) were prepared by high-energy ball milling, the effects of MWCNTs/TiF3 catalysts added alone and MWCNTs TiF3 catalysts added together on the particle morphology, phase composition and activation behavior of Mg10Ni alloys were studied. The results show that the particle size of Mg10Ni-X alloy after high-energy ball milling treatment reduces in varying degrees by adding catalyst to Mg10Ni alloy. Compared with TiF3 catalyst, MWCNTs catalyst has better particle refining effect, and the particle refining effect of composite addition of MWCNTs-TiF3 catalyst is the best. After high-energy ball milling of Mg10Ni-MWCNTs-TiF3 alloy with MWCNTs-TiF3 catalyst, the microstructures of TiF3 and MWCNTs have not changed. The order of Mg2Ni phase content and Mg2Ni phase cell volume in the alloy from large to small is: Mg10Ni-MWCNTs-TiF3>Mg10Ni-MWCNTs>Mg10Ni-TiF3>Mg10Ni. The activation performance of the alloy improves in varying degrees after the addition of MWCNTs and TiF3 catalysts, the improvement effect of TiF3 catalyst on the activation performance is better than MWCNTs, and the activation performance of the alloy after adding MWCNTs-TiF3 catalyst is the best.

In order to predict the shrinkage and deformation during the sintering process of metal green parts fabricated by binder jetting additive manufacturing (BJAM), a high-temperature creep model based on viscoelastic calculation was established to simulate the thermally induced creep behavior during the sintering process. This model establishes a connection between the microscopic and macroscopic descriptions of sintering, taking into account the effects of grain boundary diffusion, the action of gravity, grain growth, and thermal expansion on the sintering shrinkage and deformation. The parameters in the model depend on the particle size, relative density, and temperature. The numerical simulation was implemented by writing a user-defined subroutine CREEP in Abaqus, and the 316L powder widely used in industry was selected for experimental verification. The results show that the average linear shrinkage rates in the x and y directions are 11.61%, while the average linear shrinkage rate in the z direction is 12.64%. Compared with the experimental values (the average linear shrinkage rate in the x direction is 10.12%, the average linear shrinkage rate in the y direction is 10.15%, and the average linear shrinkage rate in the z direction is 11.21%), the error range is approximately 1% to 2%. This indicates that the model has a good predictive effect, especially for 316L stainless steel parts in which grain boundary diffusion is the main sintering mechanism. Optimizing and obtaining more accurate material property parameters, especially under high-temperature conditions, will help to further improve the prediction accuracy of the model.

Hot isostatic pressing (HIP) technology can be used in powder metallurgy to manufacture high-performance components, and in recent years, it has been widely applied in the fields of casting densification, diffusion bonding, and near-net-shape forming. As a green and efficient component preparation technology with simple processes and controllable properties, hot isostatic pressing powder metallurgy (HIP-PM) will be widely used in numerous industrial fields in the future, such as aerospace, nuclear power engineering, electronic information, rail transit, etc. The research progress of HIP-PM technology for duplex stainless steel (DSS) from aspects such as DSS powder preparation, the microstructure and mechanical properties of products are introduced, and corrosion resistance and the application fields and development trends of this technology are summarized.

Sintered bodies were prepared using the hot pressing sintering process from Fe-Co-Cu pre-alloyed powders of varying particle sizes. The densification, Rockwell hardness, three-point bending strength, microstructure of the two sintered bodies of different particle sizes, and interface morphology between sintered body and diamond were comparatively analyzed. Furthermore, cutting experiments were conducted to assess the cutting speed, tool life, and diamond exposure of drill bits prepared using pre-alloyed powders with varying particle sizes to further investigate their performance disparities. The results indicate that the sintered body of DB-02, prepared with pre-alloyed powder of finer particle size, exhibits higher density (96.9%)and improved toughness (with a bending strength of 1 355.7 MPa).The modified tool design also results in enhanced retention force on the diamond, leading to improved cutting efficiency, extended tool lifes, and a maximum diamond exposure height of 154.2 μm during cutting experiments.

ZrO₂ particle-reinforced copper-based friction materials were prepared by powder metallurgy (PM), and the effects of ZrO₂ contents on microstructure and properties of the materials were studied. The microstructure, density, porosity, hardness and friction and wear properties of the materials were characterized. The results show that the phase composition and distribution state of the copper base friction material are not changed significantly before and after the addition of ZrO₂ particles, and the ZrO₂ particles are evenly distributed in the matrix without agglomeration phenomenon. With the increase of ZrO₂ content, the density of the material decreases, the porosity increases, and the hardness tends to increase and then decrease. Under the test conditions of braking pressure of 1 MPa and rotation speed of 5 200 r/min, the friction factor and wear rate of the material decreases first and then increases with the increase of ZrO₂ content, and when the ZrO₂ addition reaches 8%, the friction and wear performance of the material reaches the best, the friction factor is 0.29, and the wear rate reaches the minimum value of 0.24 cm³/MJ.

Silicon carbide particle reinforced aluminum-silicon matrix composites have broad application prospects as structural functional materials in vehicle traffic, aerospace and precision instruments because of their high specific strength, high specific stiffness, good wear resistance and easy deformation. However, the coupling effect of thermal/stress field will occur in the preparation and processing of the composites, resulting in interface reaction, segregation of reinforcement phase, multi-scale precipitation of Si phase and intermetallic compound phase and microstructure evolution, which are unfavorable to the regulation of the mechanical properties of the composites. In this paper, the advantages and disadvantages of several mature preparation processes such as powder metallurgy, stir casting, impregnation and jet deposition are reviewed, and the effects of several preparation processes on the microstructure and properties of composites are analyzed

Copper and its alloys are renowned for their excellent thermal and electrical conductivity, and various other beneficial properties. Integrating these materials with the design flexibility offered by 3D printing technology can significantly improve the efficiency of heat exchange and current transmission. A comprehensive overview of recent advancements in 3D-printed copper and copper alloys was presented. It also provides a detailed comparison of the advantages and disadvantages of different forming methods, along with an analysis of existing challenges. Numerous studies indicate that achieving controlled shape and performance in 3D-printed components necessitates the integrated control and optimization of materials, structures, processes, and overall performance. However, the application of 3D printing technology to produce copper and its alloys still faces several hurdles. The low absorption and high reflectivity of copper towards laser energy complicate achieving desired structures through the selective laser melting and laser melting deposition processes. Additionally, the surface quality of components produced via the electron beam selective melting method is often suboptimal for precision manufacturing. Moreover, the binder jetting technology necessitates post-forming heat treatment, which can result in shrinkage and deformation issues. The potential applications for 3D-printed copper and copper alloys were explored, highlighting their contributions to the ongoing evolution and innovation within the advanced manufacturing sector.

Compared with laser and e-beam based additive manufacturing technologies, the combined 3D printing and sintering process is cheaper, but the exploration of the process parameters in the sintering stage is not comprehensive and in-depth enough. Therefore, the experiment uses screw-based 3D printing technology to prepare 17-4PH stainless steel samples, to explore the influence law of sintering process parameters (sintering temperature, heating rate and holding time) on the properties of 17-4PH stainless steel, including porosity and tensile property measurements, and to investigate the influence law of the sintering process parameters on the pore structure, microstructure and fracture morphology. The changes in the mechanical properties of the sintered samples were elaborated through the changes in the pore structure, microstructure and fracture morphology. The results show that the mechanical properties of the sintered samples are best when the sintered samples are heated up to 1 360 ℃ for 1 h at a rate of 4 ℃/min, with a yield strength of 518 MPa and a tensile strength of 693 MPa.

The phenomenon of rotary kiln ring seriously affects the quality of reducing materials and will reduce production efficiency, so it is necessary to explore the mechanism of powder reduction rotary kiln ring and take certain measures to alleviate this phenomenon. PB powder and anthracite were selected as the raw materials, the products reacted with refractory bricks that have Al2O3 and SiO2 as the main components, and the microstructure of different temperatures, carbon formulations and lower rings of materials were characterized by scanning electron microscopy-energy spectrum analysis. The results show that with the increase of temperature, the structure of the ring sample become tighter, the number of stomata and pore size decrease, and the white filamentous structure gradually appeares in the ring structure. When the temperature is between 1 050-1 150 °C, the ring structure still has small holes, and when the temperature rises to 1 200 °C, there are almost no pores. With the increase of carbon-oxygen ratio, the pore size of the ring material gradually increases, and when the carbon-oxygen ratio increases from 0.75 to 1.75, the pore size of the ring material increases from 0.36 μm to 0.87 μm, and it is obvious that the ring structure is gradually loosened. The particle size has a significant impact on the material ring, the larger the particle size of the material, the more difficult it is to crunch, and the ring structure is relatively loose. When anthracite coal is selected as the reducing agent, the No. 1 fine powder circle mainly contains iron phase, silicate phase and iron spinel, and the No. 2 fine powder circle mainly contains iron phase and a small amount of iron oxide phase and some silicate phase. When PB powder is selected as reduced iron ore powder, bituminous coal rings mainly contain iron phase and silicate phase.

The spherical molybdenum and molybdenum alloy TZM powders were prepared by plasma rotary electrode atomization technology, and the particle size distribution, oxygen content, micromorphism and surface tissue of tungsten powder were characterized by laser particle size analyzer, O-N analyzer, scanning electron microscope (SEM). The results show that the oxygen increments of both powders are under 50×10-6, the powder particle size is concentrated in a single-peak distribution of 45-150 μm. Because of the smaller surface tension of TZM, which has a smaller median particle size than Mo powder, and the powder has high surface quality and better process performance, which provides theoretical support for the evaluation of palladium and vanadium alloy powder for additive manufacturing.

The 4J29 alloy formed by MIM underwent post-treatment through Hot Isostatic Pressing（HIP）at various temperatures. The study is aimed to explore how HIP temperature influences the microstructure, coefficient thermal expansion and tensile behavior of the 4J29 alloy. The results reveal a gradual increase in alloy density with rising HIP temperature. However, beyond 1 200 ℃, the density enhancement rate decelerates, hardness decreases, and grain size exhibits accelerated growth. The leak rate follows a trend of initial decrease, reaching its minimum at 1 200 ℃, and then increasing. Before 1 200 ℃, the leak rate decreases with temperature, and beyond 1 200 ℃, it gradually rises. The optimum HIP temperature is 1 200 ℃, resulting in the alloy reaching a density of 98.54%, a leak rate of 1.2×10^-9 Pa·(m³/s), hardness of 81.3HRB, an average thermal expansion rate of 2.0×10^-6 m·℃ between 30~200 ℃ and along with a noticeable enhancement in tensile strength and elongation.

Particle size is an important factor affecting the performance of hydrogen storage alloy powders, and the abnormal fluctuation of particle size will lead to the decrease of the yield of Ni-MH battery negative electrode. The factors that may affect the particle size in the process of hydrogen storage alloy powder production were verified and analyzed, especially for the dry process of alloy powders, the key parameters of powder production equipment, analysis and testing equipment and sieve mesh were verified. The results show that the abnormal particle size distribution of the products in the pulverizing process has no obvious correlation with the pulverizing equipment and testing equipment, and the main cause of particle size problem is the deviation of wire diameter of screen used in pulverizing, and effective control measures are formulated accordingly.

Satellite powder is a common defect powder in metal powder preparation by atomization process. Excessive satellite powder defects affect the stability of powder laying and the density of the product. This paper starts from the principle of satellite powder defect formation by atomization process, and uses ANSYS Fluent to conduct numerical simulation in three-dimensional flow field. The influence of two novel atomization tower optimization structures formed by setting a mist protection cover and a supplementary gas device on the macroscopic airflow field in the tower were studied and the control effect of the flow field optimization structure on suppressing the formation of satellite powder was analyzed. The results show that the position and height factors of the mist protection cover affect the isolation effect of powder recirculation directly, and the position factor significant influences the distribution range of the recirculation area at the same time. Placing the mist protection cover structure of 300 mm height at a distance of 200 mm from the center axis and 250 mm from the top of the atomization tower can effectively isolate the direct impact of recirculating particles on the molten droplets in the atomization region. The pressure parameter of the supplementary gas device directly affects the isolation effect of recirculating particles and the intensity of recirculating gas clusters. Placing the supplementary gas device with a pressure parameter of 0.5 MPa at a distance of 200 mm from the center axis can provide good protection for the atomization region. Both of the two novel atomization tower optimization structures can effectively suppress the collision between particles and molten droplets in the atomization region ,thus achieving the effect of inhibiting the formation of satellite powder.

With the amount of DEA as the knob to control the nucleation-growth rate of silver particles the high performance submicron spherical silver powder was prepared using hydroquinone and ascorbic acid to reduce silver nitrate by liquid chemical reduction method. The effect of DEA content on the properties of silver powder was studied. When the DEA content is 50% of the mass of silver nitrate, submicron spherical silver powder with average particle size D₅₀ of 0.49 μm, specific surface area of 2.3 m²/g, apparent density of 1.7 g/cm³ and burning loss of 0.35% could be obtained. By X-ray diffraction (XRD) and SEM analysis, silver powder has high purity, good crystallinity and high dispersion. After the silver powder is prepared into silver paste according to the formula, the measured viscosity is 38 Pa·S/25 ℃, after screen printing and low temperature curing. It is found that the lines are relatively dense and the edge lines are flat. The resistivity of the film cured at 200 ℃ is 8.70×10^-6 Ω·m.

With the increasing demand for high performance secondary battery energy density and safety performance, the development of new type of solid-state battery is a hot spot in the field of energy researches. The key part of solid-state batteries is the solid electrolyte, and the anti-perovskite type electrolyte Li₃OCl has attracted extensive attentions due to its wide voltage window and high ionic conductivity. In general, doping modification can further improve the ionic conductivity of Li₃OCl and stabilize its cubic phase structure. However, researches on lanthanum doping using rare earth elements are still lacking. China is rich in rare-earth reserves, so it is of great value to systematically study the application of rare earth elements in Li₃OCl based batteries. Herein, the effect of lanthanum doping by Nd element on ionic conductivity of Li₃OCl electrolyte was investigated. By precisely regulating the doping amount, the ionic conductivity of Li₃OCl can be successfully increased from 5.2×10^-4 S/cm to 8.3×10^-4 S/cm. The solid-state battery realized a stable cycling at the rate as high as 3C. The doping research of Nd in Li₃OCl can provide effective theoretical guidance for the development of high-power solid-state battery and the application on new energy vehicles.

Additive manufacturing of 316L stainless steel has broad application prospects in the field of nuclear energy due to its excellent processing accuracy, surface quality, comprehensive mechanical properties, and corrosion resistance. However, when nuclear structural materials are used in irradiation environments, the defects generated by irradiation can lead to a decrease in material performance. In order to ensure the stability of the performance of AM 316L stainless steel under irradiation environment, the study of its irradiation damage effect has gradually become a hot topic of attention both domestically and internationally. Therefore, the research progress on the structure, properties, and radiation resistance of AM 316L stainless steel commonly used in the field of nuclear energy is reviewed, and some suggestions for future research directions are proposed in the article.

The influence of sample thickness, heating temperature, and carbon spray layer on the thermal diffusion coefficient of beryllium material was studied. The results indicate that the thermal diffusion coefficient on the side of the sample with a thickness ranging from 2 mm to 6 mm tends to be consistent. The standard deviation of multiple tests with a thickness of about 2 mm is the smallest, and the test results are more accurate. It is recommended to use this thickness as the sample thickness for measuring the thermal diffusion coefficient of beryllium materials. The beryllium coefficient gradually decreased with the heating temperature by 77.9% when the temperature increased from 25 ℃ to 900 ℃. Under different cases of carbon spray layer, the thermal diffusivity tested is significantly different, and the thermal diffusive coefficient measured on the test sample surface is coated with thin and uniform graphite.

In order to investigate the influence of alloy composition on the properties of soft magnetic alloy powders, 6 groups of alloy powders with varying contents of Si, Cr, and Mn were prepared by the water-gas atomization method. The saturation magnetization and coercivity of these alloy powders were characterized employing a vibrating sample magnetometer (VSM). Subsequently, the powder was compacted into magnetic powder cores, and their magnetic properties, insulation resistance, and corrosion resistance were evaluated using an LCR tester, a soft magnetic AC tester, and a salt spray tester. The results indicate that increasing the content of Si and Cr leads to a reduction in saturation magnetization and permeability. However, it significantly enhances coercivity, magnetic loss, insulation resistance, and corrosion resistance. Conversely, the incorporation of Mn into the alloy adversely affects saturation magnetization, permeability, coercivity, and hysteresis loss while improving eddy current loss and insulation resistance.

The quality control issues associated with the reuse of titanium alloy powders in the Selective Laser Melting (SLM) technology for implantable medical devices was discussed. To address this issue, the concept of powder "circulation coefficient" is introduced, and a quantitative management method for the cyclic use of powders is established. Based on this, the physical properties, chemical composition, and mechanical properties of TC4 powders with circulation coefficients of 0, 7, and 14, and their specimens, were studied respectively. The results show that as the powder circulation coefficient increases, the performance of the powder and its prepared specimens changes in a significant, linear, and predictable manner. This verifies the feasibility and effectiveness of using the powder circulation coefficient as a quality control parameter during the recycling process of TC4 powders. Furthermore, the performance of the powder and its specimens gradually decreases during the recycling process of TC4 powders, which is related to an increase in the proportion of defective particles with excessive oxygen and nitrogen content.

In response to the demand for lightweight structural materials in aviation, aerospace, high-end electronics and other fields, the application of particle reinforced aluminum matrix composites has been rapidly developed. However, at present, most of the research on aluminum matrix composites focuses on the preparation and analysis of small and medium size ingot, and the research on large size ingot and its properties and microstructure is less. The hot pressing billets with the volume fraction of 15%, 20% and 25% SiCp, the matrix alloy of 2009Al and the size of ϕ580 mm×730 mm were prepared by powder metallurgy, and the extrusion rod was extruded to ϕ250 mm. The density of the extruded rods is 100%, and the particle distribution is uniform. A small amount of Al₂Cu and Al₇Cu₂Fe are found by XRD analysis. The interface between SiCp and matrix was observed by TEM. It is found that SiCp and matrix are well combined, and no harmful interfacial reaction is observed. The tensile test at room temperature shows that the strength of the composite increases significantly with the increase of the volume fraction of SiCp. When the volume fraction of SiCp is 25%, the tensile strength of the composite is 630 MPa, the yield strength is 480 MPa, and the elongation is ≥3%. The tensile strength and yield strength of the composite are 20% and 25% higher than that of the matrix, respectively. The fracture modes of the three kinds of composites with SiCp content are dominated by the ductile fracture of the matrix alloy and the fracture of SiCp, and with the increase of the volume fraction of SiCp, the fracture phenomenon of SiCp increases significantly, and the fracture is more obvious, indicating that the high strength of the interface combination of SiCp and aluminum matrix makes SiCp plays a good bearing role.

Ultra-fine nickel powder was prepared by continuous feeding chemical vapor deposition method using NiCl₂·6H₂O as raw material. The effects of feeding rate and temperature on surface morphology of ultra-fine nickel powder were investigated. The laser particle analyzer, SEM and XRD were used to characterize the performance parameters. The results show that as the increment of feeding rate and temperature, the particle size of nickel powder gradually becomes larger, the particle size distribution is more uniform, the dispersion is better, the sphericity is higher and the crystallinity is stronger. But excessive increment in feeding rate and temperature results in the excessive growth of the particle size. The appropriate feeding rate and temperature are 135 g/h and 400 ℃ respectively.

Aluminum alloy is one of the most important nonferrous metal in the application of industry while the surface performance like hardness and wear-resistance are usually poor, restricting the further application of aluminum alloy. Laser cladding on the surface of aluminum alloy can form a metallurgical bonding coatings with substrate, which can effectively improve the surface properties of aluminum alloy. Laser cladding can also repair aluminum alloy parts, showing high application value. The laser cladding on the surface of aluminum alloy has become a hot topic at home and abroad and the related research works are increasing day by day with the continuous development of science and technology. However, there is few literature to summarize the development status of laser cladding. This paper introduces the basic knowledge of aluminum alloy laser cladding, and focuses on the current material system of laser cladding on the surface of aluminum alloy, including aluminum alloy, nickel base alloy, ceramics, high entropy alloy, etc., and briefly introduces the newly research methods and processes in this field. Finally, the development prospect of aluminum alloy laser cladding is prospected. This paper can provide reference for the researchers of laser cladding technology on the surface of aluminum alloy.

Metal based diamond composite materials have been widely used in the electronic industry and mechanical manufacturing industry due to their superior physical and mechanical properties. However, the improvement of composite material performance is limited by traditional manufacturing techniques. Additive manufacturing provides ideas for the preparation of complex structured metal based diamond composite materials. Additive manufacturing (3D printing) is a near net forming technology that transforms digital models into physical entities, with the advantage of designing and manufacturing personalized customized materials with complex structures and small anomalies. The application of 3D printing technology in manufacturing metal based diamond composite materials with better and more stable performance, while controlling production costs and reducing energy consumption, has become an inevitable trend in China's industrial development. This article summarizes the research progress of additive manufacturing technology currently used in metal based diamond composites, and puts forward prospects for further research directions in this application technology.

W-Cu composites are widely used in electronic components, particularly in high-power devices. However, as packaging requirements become more demanding, the stability of these devices must be further improved. Due to the significant intrinsic differences between W and Cu, it is challenging for W-20Cu composites to simultaneously exhibit the excellent properties of both materials. Thus, structural and organizational optimization is urgently required. Tungsten particles of varying sizes （20, 10, 5, and 2 μm） for dual particle size ratio experiments were employed to control the porosity of the W framework and promote densification of the W-20Cu composite. The results show that under the sintering conditions of 1 300 °C for 2 h, the composite produced with a particle size ratio of 10:1 and a mass ratio of 7:3 achieves the highest density of 99.12%. Moreover, the material exhibites a gas permeability of 3.1×10^-11 Pa·m³/s and a maximum flexural strength of 744 MPa. Its thermal properties include a thermal conductivity of 211 W/(m·K), slightly lower than the theoretical thermal conductivity of 220 W/(m·K), and a thermal expansion coefficient of 8.91×10^-6/K. These properties meet the performance standards required for packaging materials in electronic applications.

A TiC high manganese steel-bonded carbide with 0.1% boron addition was fabricated by powder metallurgy techiniques using TiC as hard phase and Fe, Ni, Mo, Mn, graphite C raw powders as the binder, and effects of sintering temperature on the microstructure and properties of the alloys were carried out. Microstructure observation shows that the structure of the alloy consists of black core-gray rim ceramic particles and white metallic binder, while, the ceramic particles grow gradually and its distribution become evenly with the temperature increase. The relative density of the alloy increases firstly and then decreases with the temperature increase, subsequently, the relative density of the alloy increases monotonously with the temperature increase and reaches the maximum value 98.29%. Mechanical properties results show that the hardness, transverse rupture strength (TRS) (in the as-sintered state and heat treatment state) and impact energy (IE) of the alloy increased monotonously with the temperature increase, also, reach the maximum value 63.8HRC, 1 993 MPa/1 425 MPa and 9.3 J/cm². The alloy densifies singnificantly when sintered from 1 320 ℃to 1 340 ℃, then, the hardness, TRS and IE of the alloy increases obviously. Subsequently, the increase rate of the hardness, TRS and IE of the alloy slow down which indicates the distinct role of B element in promoting densification. Boron element begins to volatilize and is exhausted completely at 1 420 ℃.The experimental alloy with B addition and the high manganese steel matrix are cast into a whole part, no obvious defects as cracks, impurities and pores are observed between the interfaces showing excellent interface bonding state and prospective long service life.