2025,Volume 54, Issue 3

>2025 Invited Manuscripts for Young Editorial Board

• Nanoflower Copper Sulfide as Cathode Materials for Magnesium Ion Batteries

  He Yuantai, Wu Liang, Shi Yongan, Zhong Zhiyong, Yao Wenhui, Pan Fusheng

  2025,54(3):545-553 DOI: 10.12442/j.issn.1002-185X.20240361

  Abstract(33) HTML(69) PDF(2.70 M)( 36)

  Abstract:CuS-C50, the cathode materials for magnesium ion batteries, was synthesized by adding the surfactant cetyltrimethyl ammonium bromide (CTAB) and adjusting the percentage of ethylene glycol to 50vol% in hydrothermal synthesis process. Results show that CuS-C50 has the complete nanoflower structure. In aluminum chloride-pentamethylcydopentodiene/tetrahydrofuran (APC/THF) electrolyte, the CuS-C50 exhibits a high specific capacity of 331.19 mAh/g when the current density is 50 mA/g and still keeps a specific capacity of 136.92 mAh/g over 50 cycles when the current density is 200 mA/g. Results of morphology characterizations indicate that the complete nanoflower structure can provide more active sites and reduce the barriers for Mg²⁺ movement, eventually improving the charge and discharge performance of the CuS cathode materials for magnesium ion batteries.

• Microstructure and Properties of Fe-Mo Functionally Graded Materials Fabricated by Electron Beam-Directional Energy Deposition

  lidanni, Yaozhengjun, Yaomengxin, Zhangshuxian, Oleksandr Moliar, Tetiana Soloviova, Iryna Trosnikova, Petro Loboda, Zhangshasha

  2025,54(3):554-568 DOI: 10.12442/j.issn.1002-185X.20240549

  Abstract(9) HTML(29) PDF(9.60 M)( 25)

  Abstract:Fe-Mo functionally graded materials (FGMs) with different composition-change rates from 100% 304 stainless steel to 100% Mo along the composition gradient direction were prepared by electron beam-directed energy deposition (EB-DED) technique, including three samples with composition mutation of 100%, composition change rate of 10% and 30%. Results show that the composition-change rate significantly affects the microstructure and mechanical properties of the samples. In the sample with abrupt change of composition, the sharp shift in composition between 304 stainless steel and Mo leads to a great difference in the microstructure and hardness near the interface between the two materials. With the increase in the number of gradient layers, the composition changes continuously along the direction of deposition height, and the microstructure morphology shows a smooth transition from 304 stainless steel to Mo, which is gradually transformed from columnar crystal to dendritic crystal. Elements Fe, Mo, and other major elements transform linearly along the gradient direction, with sufficient interlayer diffusion between the deposited layers, leading to good metallurgical bonding. The smaller the change in composition gradient, the greater the microhardness value along the deposition direction. When the composition gradient is 10%, the gradient layer exhibits higher hardness (940 HV) and excellent resistance to surface abrasion, and the overall compressive properties of the samples are better, with the compressive fracture stress in the top region reaching 750.05±14 MPa.

• Effect of Grain Size on Nano-scratching Behavior of Poly-crystalline γ-TiAl Alloy via Molecular Dynamics Simulation

  Cao Hui, Xu Hanzong, Li Haipeng, Li Haiyan, Chen Tao, Feng Ruicheng

  2025,54(3):569-580 DOI: 10.12442/j.issn.1002-185X.20240420

  Abstract(10) HTML(21) PDF(4.38 M)( 21)

  Abstract:The scratching mechanism of polycrystalline γ-TiAl alloy was investigated at the atomic scale using the molecular dynamics method, with a focus on the influence of different grain sizes. The analysis encompassed tribological characteristics, scratch morphology, subsurface defect distribution, temperature variations, and stress states during the scratching process. The findings indicate that the scratch force, number of recovered atoms, and pile-up height exhibit abrupt changes when the critical size is 9.41 nm due to the influence of the inverse Hall-Petch effect. Variations in the number of grain boundaries and randomness of grain orientation result in different accumulation patterns on the scratch surface. Notably, single crystal materials and those with 3.73 nm in grain size display more regular surface morphology. Furthermore, smaller grain size leads to an increase in average coefficient of friction, removed atoms number, and wear rate. While it also causes a larger range of temperature values and distributions. Due to the barrier effect of grain boundaries, smaller grains exhibit reduced microscopic defects. Additionally, average von Mises stress and hydrostatic compressive stress at the indenter tip decrease as grain size decreases owing to grain boundary obstruction. This work is helpful to better understand the deformation mechanism of polycrystalline γ-TiAl alloy during the nano-scratching process.

• Design and Dynamic Experiment of Al-Cu Graded Materials Impactor with Strain Rate of 10⁴–10⁵/s

  Hu Jianian, Zhou Zizheng, Li Yidi, Chen Xiang, Yang Gang, Liu Jintao, Zhang Jian

  2025,54(3):581-586 DOI: 10.12442/j.issn.1002-185X.20240293

  Abstract(6) HTML(20) PDF(1.23 M)( 21)

  Abstract:Based on simplified calculations of one-dimensional wave systems, loading pressure platform curves of Al-Cu gradient materials (GMs) impactor were designed. The Al-Cu GMs were prepared using tape-pressing sintering, and their acoustic properties were characterized to match the design path. The parallelism of the Al-Cu GM was confirmed using a three-dimensional surface profilometry machine. A one-stage light-gas gun was used to launch the Al-Cu GM, impacting an Al-LiF target at a velocity of 400 m/s. The results of the experimental strain rate demonstrate that the Al-Cu GMs can realize the precise control of the strain rate within the range of 10⁴?10⁵/s in the high-speed impact experiments.

• Hot Isostatic Pressing for Enhancing Mechanical Properties of Mo Alloys Prepared by Laser Powder Bed Fusion

  Liang Xunwen, Fu Zhongxue, Zhang Shiming, Che Yusi, Cheng Pengming, Wang Pei

  2025,54(3):587-592 DOI: 10.12442/j.issn.1002-185X.20240583

  Abstract(8) HTML(19) PDF(2.09 M)( 28)

  Abstract:To enhance the mechanical properties of Mo alloys prepared through laser powder bed fusion (LPBF), a hot isostatic pressing (HIP) treatment was used. Results show that following HIP treatment, the porosity decreases from 0.27% to 0.22%, enabling the elements Mo and Ti to diffuse fully and to distribute more uniformly, and to forming a substantial number of low-angle grain boundaries. The tensile strength soars from 286±32 MPa to 598±22 MPa, while the elongation increases from 0.08%±0.02% to 0.18%±0.02%, without notable alterations in grain morphology during the tensile deformation. HIP treatment eliminates the molten pool boundaries, which are the primary source for premature failure in LPBFed Mo alloys. Consequently, HIP treatment emerges as a novel and effective approach for strengthening the mechanical properties of LPBFed Mo alloys, offering a fresh perspective on producing high-performance Mo-based alloys.

• Advances in Residual Stress Relief Strategies at Ceramic/Metal Joint Interfaces

  Wang Xingxing, Chen Benle, Jiang Yuanlong, Pan Kunming, Ren Xuanru, Yuan Zhipeng, Zhang Yulei

  2025,54(3):618-627 DOI: 10.12442/j.issn.1002-185X.20240477

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  Abstract:As service conditions become more challenging and production complexity increases, there is an increasing demand for enhanced comprehensive performance of ceramic/metal heterostructures. At present, brazing technique has been widely utilized for ceramic-metal heterogeneous joints. However, the residual stress relief in these welding joints is complicated and necessary. Because metals and ceramics have different properties, especially their coefficients of thermal expansion. Welding joints exhibit large residual stresses during the cooling process. The relatively high residual stresses may significantly degrade the joint properties. For this issue, four alleviation routes were reviewed: optimization of process parameters, setting an intermediate layer, surface structure modulation and particle-reinforced composite solder. The states and distribution patterns of residual stress in ceramic-metal brazed joints were summarized, and the generation and detection of residual stress were introduced. Eventually, upcoming prospects and challenges of residual stress research on ceramic/metal heterostructures were pointed out.

• Review on Enhancing Separation of Heavy Metal Ions by Cyclodextrin Adsorbent Materials

  Zhang Ning, Liu Jie, Zhang Xin, Zhao Yuxiu, Xue Zhixiao, Xia Wenxiang

  2025,54(3):628-639 DOI: 10.12442/j.issn.1002-185X.20240307

  Abstract(4) HTML(14) PDF(1.71 M)( 25)

  Abstract:The traditional techniques for treating wastewater contaminated by heavy metals mostly involve chemical precipitation, solvent extraction and adsorption, ion-exchange, chemical precipitation, and membrane separation. The main shortcomings of traditional procedures are low economic efficiency, lack of environmental friendliness, and poor selectivity. Cyclodextrins are artificial compounds that resemble cages. Through host-guest interaction, pollutants can be adsorbed by its stable inner hydrophobic chamber and exterior hydrophilic surface. It is not only inexpensive and environmentally friendly, but also quite selective. The synthesis and application of materials were reviewed, as well as the primary influencing factors, and the reaction principle of cyclodextrin adsorbent materials for better separation of heavy metal ions. And the future trend of discovery was described.

• Progress on Microstructure and Performance Optimization in H/MEAs Regulated by Single and Hierarchical Heterostructures

  Wang Bing, Li Chunyan, Wang Xinhua, Li Xiaocheng, Kou Shengzhong

  2025,54(3):640-664 DOI: 10.12442/j.issn.1002-185X.20240564

  Abstract(13) HTML(17) PDF(11.66 M)( 33)

  Abstract:The development of high-performance structural and functional materials is vital in many industrial fields. High- and medium-entropy alloys (H/MEAs) with superior comprehensive properties owing to their specific microstructures are promising candidates for structural materials. More importantly, multitudinous efforts have been made to regulate the microstructures and the properties of H/MEAs to further expand their industrial applications. The various heterostructures have enormous potential for the development of H/MEAs with outstanding performance. Herein, multiple heterogeneous structures with single and hierarchical heterogeneities were discussed in detail. Moreover, preparation methods for compositional inhomogeneity, bimodal structures, dual-phase structures, lamella/layered structures, harmonic structures (core-shell), multiscale precipitates and heterostructures coupled with specific microstructures in H/MEAs were also systematically reviewed. The deformation mechanisms induced by the different heterostructures were thoroughly discussed to explore the relationship between the heterostructures and the optimized properties of H/MEAs. The contributions of the heterostructures and advanced microstructures to the H/MEAs were comprehensively elucidated to further improve the properties of the alloys. Finally, this review discussed the future challenges of high-performance H/MEAs for industrial applications and provides feasible methods for optimizing heterostructures to enhance the comprehensive properties of H/MEAs.

• Effect of Solution Cooling Rate on Microstructure and Mechanical Properties of Ultra-high Strength Titanium Alloy TB17

  Ji Xiaoyu, Xu Jianwei, Zhang Yu, Li Mingbing, Zeng Weidong, Zhu Zhishou

  2025,54(3):665-670 DOI: 10.12442/j.issn.1002-185X.20240531

  Abstract(13) HTML(31) PDF(5.89 M)( 39)

  Abstract:The effects of different cooling rates on the microstructure evolution and tensile properties of TB17 titanium alloy were studied. The results show that the cooling rate has a significant effect on the microstructure. When the cooling rate is low, the alloying elements are diffused fully, resulting in higher content and larger size of coarse lamellar layers, and a small amount of secondary α phase is precipitated in the matrix. When the cooling rate is high, a large amount of microstructure at high temperature is preserved, so that the coarse lamellar content is low and the size is small, and the secondary α phase is hardly observed. Due to the absence of external forces, the lamellar α phase maintains a strict Burgers orientation correspondence with the β phase. The tensile property is greatly affected by the solution cooling rate. A large amount of secondary α phase is precipitated during air-cooling (AC), which results in the highest strength. Due to the faster cooling speed, only the coarse layer is retained during water-quenching (WQ), resulting in the lowest strength. The cooling rate of furnace-cooled (FC) is too slow, so the coarse lamellar growth is obvious. This inhibits the precipitation of secondary α phase, and leads to the middle intensity. After aging treatment, the tensile properties change differently. WQ has the highest strength, while FC has the lowest strength.

• Phase Field Simulation of Pressure-Assisted Sintering Process of Uranium Nitride

  Sun Qiming, Shen Wenlong, Liao Yuxuan, Li Yu, Wang Jijun, Liu Wenbo

  2025,54(3):671-678 DOI: 10.12442/j.issn.1002-185X.20240497

  Abstract(8) HTML(22) PDF(2.18 M)( 29)

  Abstract:The pressure applied during the sintering process plays an important role in improving the final density of UN pellets. In this work, a phase field model of UN pressure-assisted sintering was established by introducing elastic strain energy and particle rigid motion process. The effects of stress on the growth of sintering neck and rigid-body motion on the pore shrinkage were analyzed, and the multi-particle sintering process under the three mechanisms was simulated. The simulation results show that the length of the sintering neck and its growth rate increase with the increase in the applied strain. There is obvious stress concentration at both ends of the sintering neck, and the stress distribution gradually becomes uniform with the increase in time. With the increase in translational mobility, the pore shrinkage rate increases, and the densification completion time is advanced, while the value of rotational mobility has little effect on the pore shrinkage process. The model can capture the formation and growth of the sintering neck, the spheroidization and closure of the pores. The coordination grain number of large volume pores is higher and the existence time is longer.

• Microstructure and Mechanical Properties of TiAl Alloy Fabricated by Laser Melting Deposition

  Chen Yongning, Xiao Huaqiang, Chu Mengya, Mo Taiqian

  2025,54(3):679-687 DOI: 10.12442/j.issn.1002-185X.20240587

  Abstract(8) HTML(19) PDF(12.17 M)( 31)

  Abstract:Complex shaped TiAl alloy components can be manufactured by laser additive manufacturing technology, further expanding the engineering applications of this lightweight high-temperature alloy in the aerospace field. However, there is currently limited research on the intrinsic relationship among the laser melting deposition process, microstructure, and properties of TiAl alloys. TiAl alloy specimens with good macroscopic quality were prepared by laser melting deposition using Ti-48Al-2Cr-2Nb alloy powder as raw materials. The microstructure, phase composition, hardness distribution of the deposited layer, and room temperature mechanical properties of the deposited specimens were studied under optimized process parameters. The results show that the microstructure of the deposited layer mainly consists of a large number of γ-TiAl phases and a small amount of α₂-Ti₃Al phases; the microstructure of the deposited sample exhibits a layer characteristics formed by columnar crystals, equiaxial crystals, cytosolic crystals, and laths structure, and the grain refinement in the microstructure of the deposited layer is obvious. The hardness distribution of the deposited layer ranges from 537 HV_0.3 to 598 HV_0.3, and the Vickers hardness at the bottom is higher than that at the middle and the top. The ultimate compressive strength of the TiAl alloy specimens is (1545±64) MPa at room temperature, with a compressive strain of (17.68±0.07)%, and the ultimate tensile strength along the scanning direction of the laser is (514±92) MPa at room temperature, with an elongation of (0.2±0.04)% after break; the ultimate tensile strength along the building direction is (424±114) MPa, with an elongation of (0.15±0.07)% after break. The tensile fracture morphology of TiAl alloy specimens exhibits quasi cleavage fracture characteristics. By optimizing the scanning strategy and assisting with subsequent heat treatment, it is expected to improve the uniformity of alloy structure and the anisotropy of mechanical properties.

• Deep Penetration Mechanism of Dual Pulse TIG Welding for Medium-Thick Titanium Alloys

  Yang Qingfu, Luo Zhiwei, Zeng Caiyou, Jiang Zihao, Cong Baoqiang, Qi Bojin

  2025,54(3):688-696 DOI: 10.12442/j.issn.1002-185X.20240680

  Abstract(8) HTML(38) PDF(10.05 M)( 32)

  Abstract:In response to the issues of shallow TIG arc penetration and low welding efficiency in medium-thickness titanium alloy arc welding, TIG welding experiments were conducted on 6 mm-thick TC4 titanium alloy. The effects of different arc modes (direct current, low-frequency pulse, and low-frequency plus high-frequency dual-pulse) on the weld pool and weld bead formation were studied. Finite element simulation was employed to investigate the temperature field and flow field dynamics of the weld pool in dual-pulse welding, and the deep penetration mechanism of dual-pulse TIG welding was analyzed. The results show that compared to constant current and low-frequency pulse modes, the dual-pulse current mode increases the flow velocity of the weld pool, effectively excites the deep penetration keyhole at the center of the pool, promotes the downward movement of the heat source, and thus increases the penetration depth. The tensile strength of the dual-pulse TIG weld joint reaches 964 MPa, the joint strength coefficient is 98%, and the post-fracture elongation is 3.7%, achieving a near-equal strength match for the joint.

• Effects of Pulsed Magnetic Field Treatment on Tribological Properties of Cemented Carbide/Titanium Alloy

  Chen Zhe, Xu Yangyang, Yan Qiaosong, Chen Yitong, Zhang Lin, Wu Mingxia, Liu Jian

  2025,54(3):697-705 DOI: 10.12442/j.issn.1002-185X.20240525

  Abstract(13) HTML(17) PDF(13.28 M)( 27)

  Abstract:WC-Co cemented carbide balls with different cobalt (Co) contents were modified by pulsed magnetic field. The effects of pulsed magnetic field treatment on tribological properties of YG6/YG8/YG12-titanium alloy (TC4) were investigated by reciprocating friction machine and SEM. The results show that pulsed magnetic field treatment can effectively reduce the coefficient of friction (COF) of YG cemented carbides-TC4 titanium alloy friction pair. Main wear forms are adhesive wear and oxidation wear. Different intensities of pulsed magnetic field change the energy amount generated. Taking YG8 as an example, the average COF are reduced by 20.5%, 29.7%, and 25.9%, after the magnetic 0.5, 1, and 1.5 T treatments, respectively, compared with that without treatment. At magnetic field intensity of 1 T, the average COF of YG6, YG8, YG12 cemented carbide decreases by 19.5%, 29.7%, 20.1%, respectively. With the increase in Co content, the effect of the magnetic field treatment increases first and then decreases, and the magnetic field response is the most significant when the Co content is 8wt%. As an external energy, the pulsed magnetic field used on cemented carbide causes the Co phase from α-Co to ε-Co and thus results in dislocation proliferation; as a result, the ability of cemented carbide to resist plastic deformation is improved, and the corresponding macro-phenomenon is an increase in strength and wear resistance, so that the friction performance is finally improved.

• Microstructure and Mechanical Properties of Mg-4Y-3Nd-0.5Zr Alloy Fabricated by Wire Arc Additive Manufacturing

  Chang Zijin, Zhang Ruize, Zeng Caiyou, Yu Kai, Li Ziqi, Cong Baoqiang

  2025,54(3):706-713 DOI: 10.12442/j.issn.1002-185X.20240675

  Abstract(8) HTML(17) PDF(10.53 M)( 23)

  Abstract:A WE43 (Mg-4Y-3Nd-0.5Zr, wt%) magnesium-rare earth alloy thin-wall component was fabricated by wire arc additive manufacturing, and its microstructure and mechanical properties were investigated by multiscale characterization, microhardness, and tensile tests. The influences of direct aging (T5) and solid solution+aging (T6) on the microstructure evolution and mechanical properties were studied. Results indicate that the as-deposited WE43 alloy has a uniform equiaxed crystal matrix, with an average grain size of 25.3 μm. Reticulated eutectic structure (α-Mg+Mg₄₁Nd₅/Mg₂₄Y₅) is formed due to Nd and Y element liquid segregation at grain boundaries. Tensile strength of as-deposited alloys is 190 MPa. Peak hardness increases from 74 HV_0.2 to 91 HV_0.2 after T5 aging with persistence of significant eutectic structures. Peak aging hardness is 108 HV_0.2 after T6 treatment, and the eutectic structure is dissolved completely, while a small amount of Mg₂₄Y₅ remains in matrix. Tensile strength of alloys is enhanced to 283 MPa after T6 treatment, but it also induces significant grain growth and reduces the elongation in vertical direction more obviously than in horizontal direction.

• Johnson-Cook Constitutive Model and Failure Parameters of Mg-9Gd-4Y-2Zn-0.5Zr Alloy

  Zhi Huidong, Guo Baoquan, Ding Ning, Yan Zhaoming, Zhu Jiaxuan, Wan Chen

  2025,54(3):714-721 DOI: 10.12442/j.issn.1002-185X.20240505

  Abstract(15) HTML(17) PDF(3.83 M)( 23)

  Abstract:The mechanical behavior and fracture failure characteristics of Mg-9Gd-4Y-2Zn-0.5Zr alloy at various strain rates were investigated, including parameter calibration and verification based on the Johnson-Cook (J-C) constitutive model and failure model. Quasi-static tensile tests at different temperatures were conducted by a universal testing machine, while dynamic tensile tests at high strain rates (1000–3000 s^-1) were performed by a Hopkinson bar apparatus. Based on the experimental data, modifications were made to the strain rate hardening and thermal softening terms of the J-C constitutive model were modificated, and relevant model parameters were calibrated. Further numerical simulations were carried out; the fracture locations and true stress-strain curves between experimental and simulated results were compared to validate the reliability of the failure model parameters. The fracture morphology of the magnesium alloy was observed and the microstructural characteristics influencing failure under different temperatures and strain rates were explored. Both dimples and cleavage steps were observed in the fracture morphologies during quasi-static and dynamic tensile processes, indicating a mixed fracture mechanism. Slightly more cleavage steps are found at higher strain rates, which is related to the strain rate sensitivity of the magnesium alloy. In contrast, ductile fracture is predominant during high-temperature tensile tests.

• Research Progress on Effects of Rare Metals on Marine Atmospheric Corrosion Behavior of Steel

  Liu Feiyang, Li Tianke, Wang Ruixin, Guo Bin, Ai Yuanlin, Tang Yu

  2025,54(3):791-802 DOI: 10.12442/j.issn.1002-185X.20240533

  Abstract(15) HTML(15) PDF(5.77 M)( 17)

  Abstract:Steel material is the main structural material of marine equipment, but its corrosion usually occurs in the marine atmosphere environment, thus affecting its service performance. Compared with general atmospheric corrosion, marine atmospheric corrosion is affected by sea salt aerosols, chloride ions and other specific factors of marine atmosphere. In addition, the marine atmospheric corrosion properties of steel materials are closely related to the alloying elements of the materials. This paper reviewed the relevant studies of worldwide scholars on the effect of rare metal doping on the marine atmospheric corrosion resistance of steel materials in recent years, and summarized the corrosion mechanism of carbon steel, stainless steel, weathering steel and other common structural steels under marine atmospheric environment. The effects of Nb, Mo, Sb, Sn, Ce, La, Y and other rare metal elements on the marine atmospheric corrosion resistance of steel materials were analyzed. For weathering steel and carbon steel, the effect of rare metal elements on the structure of rust layer was mainly discussed. For stainless steel, the effect mechanism of rare metal elements on inclusion modification and pitting behavior of stainless steel was discussed. The future research directions were prospected, in order to provide references for the application of rare metal doped steel in marine atmospheric environment and for the improvement of marine atmospheric corrosion resistance.

• Research Progress on High-Temperature Oxidation Protection of TiAl Alloys

  Ye Xinyu, Wu Liankui, Cao Fahe

  2025,54(3):803-817 DOI: 10.12442/j.issn.1002-185X.20240508

  Abstract(6) HTML(17) PDF(5.45 M)( 18)

  Abstract:The TiAl alloy is considered a promising material for aerospace and other high temperature applications due to its low density, high strength and excellent creep resistance. However, its application is currently limited by its poor oxidation resistance above 750 ℃. In this paper, the classification, development, and high temperature oxidation behavior of TiAl alloys were reviewed. The formation mechanism and structural evolution of oxide films were discussed. The research progress of the preparation processing, bulk alloying, reinforcing phase and surface modification technologies aimed at improving the high temperature oxidation resistance of TiAl alloys since the 21st century were summarized. Furthermore, the application of theoretical calculation in oxidation process was discussed and the development trend of this field was prospected.

• Research Progress on Brazing Copper with Dissimilar Materials

  Long Fei, Song Kexing, Zhang Zhaoqi, Wang Ce, He Peng, Sun Jun

  2025,54(3):818-836 DOI: 10.12442/j.issn.1002-185X.20240629

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  Abstract:The basic properties, structural, and functional applications of copper were described and the process characteristics and joint properties of copper brazing were and analyzed. The current research status of brazing between copper and dissimilar materials such as steel, aluminum, titanium, ceramics, and carbon-based materials were reviewed and examples of studies on brazing copper with heterogeneous structures were listed. Specific considerations in the brazing process were also examined, including brazing filler metal selection, process formulation, interlayer design, use of brazing equipment, and performance inspection. The importance of joining structure and joint interface design was emphasized. Furthermore, it is proposed that the development direction of copper brazing should focus on being green, intelligent, reliable, and low-cost, providing a technical reference for the engineering applications of copper and the brazing fabrication of heterogeneous structures containing copper.

>Materials Science

• Solid-Solution Heat Treatments Effect on Microstructure and Mechanical Properties of Low-Oxygen TZM Alloy

  Xing Hairui, Shi Qianshuan, Hu Boliang, Li Shilei, Li Yanchao, Wang Hua, Wang Qiang, Xu Liujie, Feng Rui, Zhang Wen, Hu Ping, Wang Kuaishe

  2025,54(3):593-603 DOI: 10.12442/j.issn.1002-185X.20240560

  Abstract(8) HTML(18) PDF(4.08 M)( 18)

  Abstract:Low-oxygen TZM alloy (oxygen content of 0.03vol%) was subjected to solid-solution heat treatment at various temperatures followed by quenching. Results show that the tensile strength of the alloy gradually decreases with the increase in solid-solution temperature, and the elongation first increases and then decreases. The the amount of nanoscale Ti-rich phases precipitated in low-oxygen TZM alloys gradually increases with the increase in solid-solution temperature. Special strip-shaped Ti-rich areas appear in the samples solidified at 1200 and 1300 °C. The nanoscale Ti-rich phases ensure the uniform distribution of dislocations throughout TZM alloy, while significantly improving the plasticity of low-oxygen TZM alloy samples.

• Trial Production of Heavy-Duty Metal Rubber Based on Predictive Model of Relative Density Mechanics

  Hao Huirong, Wang Jiawei, Zhao Wenchao, Ren Jiangpeng

  2025,54(3):604-611 DOI: 10.12442/j.issn.1002-185X.20240116

  Abstract(7) HTML(10) PDF(2.00 M)( 18)

  Abstract:The predictive model and design of heavy-duty metal rubber shock absorber for the powertrains of heavy-load mining vehicles were investigated. The microstructural characteristics of the wire mesh were elucidated using fractal graphs. A numerical model based on virtual fabrication technique was established to propose a design scheme for the wire mesh component. Four sets of wire mesh shock absorbers with various relative densities were prepared and a predictive model based on these relative densities was established through mechanical testing. To further enhance the predictive accuracy, a variable transposition fitting method was proposed to refine the model. Residual analysis was employed to quantitatively validate the results against those obtained from an experimental control group. The results show that the improved model exhibits higher predictive accuracy than the original model, with the determination coefficient (R²) of 0.9624. This study provides theoretical support for designing wire mesh shock absorbers with reduced testing requirements and enhanced design efficiency.

• Quantitative Strengthening Evaluation of Mg-Zn-Y Alloys Containing Icosahedral Quasi-Crystalline Phase

  Wang Yingnan, Meng Xiaokai, Guo Junhong

  2025,54(3):612-617 DOI: 10.12442/j.issn.1002-185X.20240183

  Abstract(5) HTML(13) PDF(1.72 M)( 14)

  Abstract:Mg-4.8Zn-0.8Y, Mg-18Zn-3Y, Mg-15Zn-5Y, Mg-30Zn-5Y and Mg-42Zn-7Y (wt%) alloys containing icosahedral quasi-crystalline phases were prepared using the ordinary solidification method. The impact of Mg matrix porosity on the tensile strength and hardness of the alloys was studied. The porosity of the Mg matrix was quantitatively assessed using scanning electron microscope and Image-Pro Plus 6.0 software. Tensile tests were conducted at room temperature. Results show that the maximum tensile strength of the alloy is 175.56 MPa, with a corresponding Mg matrix porosity of 76.74%. Through fitting analysis, it is determined that the maximum tensile strength is achieved when the porosity of the Mg matrix is 64.87%. The microhardness test results indicate a gradual decrease in alloy hardness with increasing the porosity of Mg matrix. This study provides an effective quantitative analysis method for enhancing the mechanical properties of magnesium alloys.

• Microstructure and Properties of Al-Zn-Mg-Cu-Zr Alloy with Low Scandium Content

  Zhu Biwu, Xiao Gang, Liu Xiao, Ye Fan, Zhang Wei, Cui Xiaoli, Zhan Haihong, Liu Wenhui

  2025,54(3):722-729 DOI: 10.12442/j.issn.1002-185X.20240552

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  Abstract:The relationship between the mechanical properties and precipitation behavior of Al-Zn-Mg-Cu-Zr aluminum alloys with low Sc content (0.02wt%, 0.07wt%, 0.12wt%) was investigated by OM, SEM, TEM, and universal material testing machine. With the increase in Sc content, microstructure of as-cast alloy is gradually refined, and the coarse secondary phase at the grain boundary increases, thus weakening the effect of fine grain strengthening. In the alloy at rolling+T6 state, the Al₃(Sc,Zr) phase inhibits the precipitation of the main strengthening phase η', and the inhibition effect becomes more obvious with the increase in Sc content, thus weakening the precipitation strengthening effect. The grain refinement is conducive to the formation of more and finer dimples during the tensile deformation, thus improving the ductility of the alloy. The low Sc content alloy (0.02wt%) shows the excellent mechanical properties after rolling and T6 heat treatment, whose tensile strength and elongation are 683 MPa and 21%, respectively.

• Preparation of Fe₃O₄@SiO₂@CM-β-CD Magnetic Nanomaterials and Its Their Adsorption Properties on Er(Ⅲ)

  Zhao Yuxiu, Liu Jie, Zhang Ning, Zhang Xin, Xue Zhixiao, Zhang Qiulu, Li Qianting

  2025,54(3):730-740 DOI: 10.12442/j.issn.1002-185X.20230715

  Abstract(8) HTML(12) PDF(4.70 M)( 13)

  Abstract:Fe₃O₄ magnetic nanoparticles were prepared by co-precipitation method, the surface of the magnetic particles was modified by SiO₂ and CM-β-CD, and Fe₃O₄-based magnetic nanomaterials (Fe₃O₄@SiO₂@CM-β-CD) with high adsorption properties were prepared. Single factor optimization experiments were carried out, and the physical and chemical properties of magnetic nanocomposites were characterized by TEM, EDS and BET. The adsorption behavior of Fe₃O₄@SiO₂@CM-β-CD on rare earth Er(Ⅲ) was investigated. The effects of adsorbent dosage, temperature and rotational speed on erbium removal rate were also investigated. The results show that when the dosage of SDBS is 1 g, the dosage of TEOS is 6 mL, the dosage of APTES is 1 mL, and the dosage of CM-β-CD is 0.5 g, the adsorption rate of Er(Ⅲ) can preferably reach more than 95%. When the contact time is 30 min, the initial concentration of Er(Ⅲ) is 10 mg/L, the initial pH is 4.5, the dosage of adsorbent is 30 mg, the temperature is 298 K, and the rotational speed is 150 r/min, the removal rate of Er(Ⅲ) is about 98%. After the adsorption of erbium, the nanomaterials were desorbed with 0.1 mol/L HNO₃ for 20 min, and the desorption efficiency of rare earth Er(Ⅲ) can be more than 87%. The adsorption mechanism of Fe₃O₄@SiO₂@CM-β-CD was investigated by XPS analysis. It is found that the adsorption of Fe₃O₄@SiO₂@CM-β-CD on Er(Ⅲ) is mainly by the inclusion of cyclodextrin cavity, supplemented by electrostatic adsorption and chemisorption. The results of this study can provide a new method for efficient recovery of rare earth elements with low concentration in aqueous solution.

• Microstructure and Oxidation Resistance of Self-Passivating W-Si-Zr Alloys

  Zhang Shirong, Chen Shijie, Wang Rui, Ye Chao, Xue Lihong, Zhou Qilai, Yan Youwei

  2025,54(3):741-746 DOI: 10.12442/j.issn.1002-185X.20230722

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  Abstract:Self-passivating W-Si-Zr alloys were prepared by mechanical alloying and spark plasma sintering. Microstructures of alloys were characterized by XRD, XPS, SEM and EPMA, and their oxidation resistance was tested. The results show that the alloy contains W-enriched, W₅Si₃, SiO_x (x=1, 1.5, 2) and ZrO_x (x=1, 1.5, 2) phases. The W₅Si₃ phase distributes continuously. SiO_x and ZrO_x particles are dispersed in the matrix with the sizes of 1.0–2.5 μm and 0.7–2.7 μm, respectively, and ZrO_x particles are often associated with SiO_x particles. The W₅Si₃ plays a key role in the oxidation resistance of the alloy. The addition of Zr contributes to the formation of W₅Si₃ phase, whose area reaches 70.2%. The oxidation rate of W-Si-Zr alloy is about 1/2 of that of W-Si alloy and 1/36 of that of pure W at 1000 ℃ in the air.

• Effect of Mg on Cast Microstructure and Mechanical Properties of S44660 Super Ferritic Stainless Steel

  Fan Wenjie, Ning Likui, Chang Dongxu, Ding Dong, Li Guanglong, Liu Enze, Tan Zheng, Tong Jian, Li Haiying, Zheng Zhi

  2025,54(3):747-754 DOI: 10.12442/j.issn.1002-185X.20230724

  Abstract(10) HTML(13) PDF(7.03 M)( 16)

  Abstract:To study the effect of Mg on super ferritic stainless steel, the content of Mg in S44660 super ferritic stainless steel was adjusted, and four kinds of test steels without Mg and with Mg additions of 0.0002%, 0.0004% and 0.0010% (mass fraction) were prepared. The effects of Mg on the cast microstructure and mechanical properties of S44660 super ferritic stainless steel were studied. The results show that the average grain size of the steel decreases from 1.14 mm to about 0.83 mm after 0.0002% Mg is added, and with the further increase in Mg content to 0.0004% and 0.0010%, the average grain size decreases to about 0.62 and 0.59 mm. It is confirmed that Mg can refine the grain of S44660 steel. Typical inclusion type of the S44660 steel is Ti-O-N composite inclusion, while it changes into Ti-O-Al-Mg-N composite inclusion after adding Mg, and the inclusion content and size decrease at the same time. The yield strength and tensile strength of the steel increase after adding Mg. Therefore, Mg can improve the impact absorption energy and hardness of S44660 super ferritic stainless steel.

• Effects of Rare Earth La-Yb Doping on Microstructure and Electrochemical Performance of Magnesium Alloys Used as Anode for Seawater Batteries

  Yang Qingzhu, Lian Lixian, Liu Ying

  2025,54(3):755-764 DOI: 10.12442/j.issn.1002-185X.20230730

  Abstract(7) HTML(11) PDF(8.33 M)( 9)

  Abstract:AZ91-La-Yb magnesium alloy as anode of seawater batteries was prepared by combining mechanical alloying with spark plasma sintering processes. The effects of rare earth La-Yb doping on the microstructure and electrochemical behavior of AZ91 anode were studied. The results show that the AZ91-La-Yb alloy prepared by mechanical alloying-spark plasma sintering processes consists of equiaxed grains. On the one hand, La-Yb doping results in the formation of micron-scale (0.5–2 μm) RE-rich phase that are uniformly distributed at grain boundaries. This phase is mainly composed of rare earth metals (RE=La, Yb) and Mg(RE) solid solution. On the other hand, the plastic deformation caused by discharge plasma sintering and the doping effect of rare earth elements La-Yb significantly improve the morphology of β-Mg₁₇Al₁₂ phase, transforming from a coarse network structure to a slender elongated shape. The combination of uniform distribution of nearly micron-scale RE-rich phase and the smaller β phase promotes the uniform dissolution of magnesium alloys and effectively alleviates localized corrosion of magnesium alloys. Compared to the AZ91 anode magnesium alloy, the AZ91-La-Yb alloy doped with rare earth La-Yb exhibits more stable discharge voltage and excellent discharge performance. At a current density of 20 mA/cm², its specific capacity can reach 1068 mAh/g, and the anode utilization efficiency is 50.4%.

• Microstructure， Thermal and Mechanical Properties of γ Phase in Mn-rich NiMnGa Alloy

  Zhou Yuecong, Ouyang Sheng, Deng Cuizhen, Long Jian

  2025,54(3):765-773 DOI: 10.12442/j.issn.1002-185X.20230736

  Abstract(8) HTML(10) PDF(6.38 M)( 9)

  Abstract:Brittleness of traditional Ni-Mn-Ga alloy is a marjor obstacle for its practical applications, as actuators and sensors. The Ni-rich Ni-Mn-Ga alloy can significantly improve the ductility. However, the shape memory strain is significantly reduced. Higher martensitic transformation temperature, good thermal stability and moderate shape memory property are shown in Mn-rich Ni-Mn-Ga. In the present work, microstructural feature, mechanical properties and thermal property of Ni₅₄Mn_28+xGa_18-x(x=0, 4, 7, 9, 13) were investigated. As the Mn content increases, the γ phase appears, with is a face centered tetragonal (fct) structure, and a γ grain contains a hierarchical "nano-lamellae forming within micro-lamellae" microstructure. A micro-lamella consists of two variants, each variant has a pair of nano-lamellae, and they are {011} twin related. Owing to the introduction of lamellar γ, the ductility is improved. With the increase in Mn content, the compressive stress increases from 914 MPa to 2175 MPa, and the compressive strain increases from 14% to 26%. The martensitic transformation temperature of such series of alloys increases from 352 ℃ to 585 ℃. For Mn-rich Ni-Mn-Ga alloy, the ductility improvement is inferior to that of Ni-rich alloy, but the martensitic transformation temperature is higher.

• Effects of Cr and Zr on Interface Microstructures and Properties of CuW/CuCr Integral Materials

  Yang Xiaohong, Liu Zixian, Li Xuejian, Xiao Peng, Liang Shuhua

  2025,54(3):774-780 DOI: 10.12442/j.issn.1002-185X.20230737

  Abstract(15) HTML(15) PDF(3.44 M)( 20)

  Abstract:CuW/CuCr integral materials with Cu-Cr-Zr powder interlayer was prepared by integral sintering infiltration method. The effects of Cr and Zr content and solution aging heat treatment on the microstructure and properties of the interface and both sides of the material were studied. The results show that with the increase in Zr content in Cu-15%Cr-x%Zr (mass fraction, similarly hereinafter) interlayer, the eutectic phase amount on CuCr side of the integral material increases, and the conductivity at CuCr end decreases. The hardness increases first and then decreases. At the same time, the addition of Zr promotes the diffusion of Cr into W. The tensile test bars of integral materials with different interlayers were prepared, and the interfacial tensile strength was tested and the fracture morphology was analyzed. It is found that when the Zr content in the interlayer is 0.5%, the interfacial tensile strength of the whole material reaches the maximum value of 517 MPa, which is 18% higher than that of the CuW/CuCr integral material with Cu-15%Cr interlayer without Zr. The tearing edge of Cu phase in the tensile fracture becomes shallower and shorter, and the number of cleavage fractures of W particles increases, which indicates that the interfacial strength of Cu/W phase and the end strength of CuCr are improved.

• Diffusion Behavior of Elements at Cu/Ti Bimetallic Liquid-Solid Composite Interface

  Shao Peng, Chen Xuan, Huang Sheng, Yu Kun, Chen Hao, Liu Kun, Xiao Han

  2025,54(3):781-790 DOI: 10.12442/j.issn.1002-185X.20230745

  Abstract(15) HTML(12) PDF(6.69 M)( 12)

  Abstract:The Cu-Ti bimetallic composites were prepared by liquid-solid composite process, and the diffusion behavior of Cu and Ti elements at the composite interface was investigated by OM, SEM, EPMA and other testing methods. The results show that the grain boundaries are the main channels for diffusion in the process of Cu/Ti composite. Except for part of the Cu₄Ti phase formed on the Cu matrix, the rest of the compound phases of the diffusively-dissolved layer are generated on the Ti matrix. The compounds generated at the Cu-Ti composite interface are Cu₄Ti, Cu₃Ti₂, CuTi and CuTi₂, where the Cu₃Ti₂ phase grows in a “jagged” manner, the CuTi phase grows in a “bamboo shoot” manner, and the CuTi₂ phase grows in a “planar” manner. The hardness values of the diffusion-dissolved layer are significantly higher than those of the two pure components. As verified by the Miedema model, the sequence of interfacial phase precipitation is CuTi, Cu₃Ti₂, CuTi₂ and Cu₄Ti. The bonding of Cu and Ti is a combined action of Cu diffusion in Ti matrix and Ti dissolution in the Cu solution.

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• Deformation Behavior And Related Dynamic Recrystallization Mechanism Of High Purity Copper During Hot Deformation

  haohuijun, yanganheng, chengjun, zhouwenyan, kangfeifei, maoyong, hejunjie

  Available online:April 03, 2025  DOI: 10.12442/j.issn.1002-185X.20240678

  Abstract(3) PDF(2.69 M)(0)

  Abstract:The microstructure of high-purity copper targets has a significant impact on the quality of sputtered films. This study investigates the evolution of the microstructure and dynamic recrystallization mechanism of copper targets from the perspective of hot working. The hot deformation behavior of high-purity copper at temperatures ranging from 500 to 650°C and strain rates of 0.01 to 10 s-1 was studied through isothermal compression experiments. The results show that the evolution of the microstructure and the recrystallization mechanism are closely related to the Zener-Hollomon parameter. As the temperature increases and the strain rate decreases, the lnZ decreases, and the average grain size decrease, both the microstructure homogenize and dynamic recrystallization enhance, and the texture transitions from a strong deformation texture of CubeND{001}<110> to Cube{001}<100> and Goss{011}<100>. The dynamic recrystallization mechanism changes at different lnZ values. Local recrystallization occurs at high lnZ values, which is a discontinuous dynamic recrystallization (DDRX) mode. At middle lnZ value, the degree of recrystallization increases, the orientation difference increases uniformly and the lattice rotates gradually. At low lnZ values, continuous dynamic recrystallization (CDRX) of progressive rotation of lattice and geometric dynamic recrystallization (GDRX) of grain "pinching" occur, at low lnZ value of 650℃, 10s-1, homogeneous fine microstructure and weak texture strength are obtained. The research can provide theoretical guidance for the optimization of hot working technology of high purity metal sputtering targets.

• Microstructure and mechanical properties of EA4T steel repaired by laser cladding IN625 alloy

  Fang Xifeng, Wang Rui, Huo Huibin, Yang Qian, Sun Xiaoguang

  Available online:April 03, 2025  DOI: 10.12442/j.issn.1002-185X.20240681

  Abstract(2) PDF(1.75 M)(0)

  Abstract:IN625 superalloy was used to repair the surface of EA4T axle steel by laser. The phase composition, microstructure, grain size and mechanical properties of different areas of IN625 laser cladding samples were analyzed by X-ray diffractometer, scanning electron microscope, Vickers hardness tester and universal experimental machine. The results show that the bottom of the IN625 laser cladding layer is the columnar crystal structure with multiple growth directions, the middle is the columnar crystal structure with single growth direction and the grain size is the largest, and the top is the mixed crystal region dominated by equiaxial crystal; The interdiffusion of Ni, Cr and Fe occurs between the cladding layer and the substrate, and the diffusion region is about 9 μm. The microhardness is 295HV_0.2, the tensile strength is 888 MPa and the elongation is 38.0% .

• Effects of Rolling Deformation and Solution Treatment on the Microstructure and Texture of IMI834 Plate

  Yang Nan, Wang Ruiqin, Shi Lichao, Chen Zhiting, Yang Heng, Peng Chen, Zhang Shuang

  Available online:April 03, 2025  DOI: 10.12442/j.issn.1002-185X.20240683

  Abstract(2) PDF(1.53 M)(0)

  Abstract:IMI834, as a high-performance titanium alloy resistant to 600℃ high temperatures, faces limitations in its application due to issues such as a narrow processing window, weak deformation ability, and high deformation resistance. Although controlling the sheet"s microstructure and texture by adjusting the rolling thickness and post-rolling heat treatment is feasible, related research remains insufficient. In this study, scanning electron microscopy and backscattered electron diffraction techniques were employed to investigate the effects of deformation and solution treatment temperature on the microstructure and texture of IMI834 sheets. The results indicate that as the rolling deformation increases, the sheet"s microstructure gradually transforms into banded and equiaxed fine-grained structures, with the banded structure exhibiting an RD texture. Additionally, reversing the rolling direction can increase the proportion of equiaxed fine-grained structures. Appropriate solution treatment can effectively weaken the basal texture, thereby reducing the sheet"s deformation anisotropy. This study provides both theoretical and practical foundations for controlling the texture and improving the performance anisotropy of near-α high-temperature titanium alloy sheets.

• Effect of Ta element on microstructure and mechanical properties of Nb-22Si-20Ti-6Mo alloy

  Qin Xu, Xiaohang Ma, Qi Wang, Jiantong Wang, Dezhi Chen, Yajun Yin, Ruirun Chen

  Available online:April 03, 2025  DOI: 10.12442/j.issn.1002-185X.20240685

  Abstract(2) PDF(1.05 M)(0)

  Abstract:Nb-22Si-20Ti-6Mo-xTa (x = 0, 1, 2, 3, 4 at.%) alloys with different content of Ta were prepared by vacuum non-consumable arc melting method, and effects of Ta content on phase constitution, microstructure and mechanical properties of Nb-22Si-20Ti-6Mo-xTa alloys were investigated. Results show that addition of Ta does not change the phase composition Nb-22Si-20Ti-6Mo-xTa alloys. All alloys are consisted of Nbss and β-Nb5Si3, Ta is mainly dissolved in Nbss. Microstructure of alloys consisted of bulk primary β-Nb5Si3 phase and Nbss/β-Nb5Si3 eutectic. Addition of Ta refined microstructure, and grain size of primary β-Nb5Si3 phase decreased from 26.84 μm to 14.65 μm. In addition, the amount of primary phase are decreased with increasing of Ta, the amount of eutectic structure are increased. Room-temperature compressive strength of Nb-22Si-20Ti-6Mo-xTa alloys was improved with increasing of Ta content, and it is increased from 2261MPa to 2321 MPa with increasing content of Ta from 0 to 4at.%. Fracture strain of Nb-22Si-20Ti-6Mo-xTa alloys first decrease and then increase with increasing of Ta content. Fracture strain of NST-0Ta alloy is 9.9%, that of NST-1Ta alloy is 9.7%, and that of NST-4Ta alloy increases to a maximum of 10.6%. Compressive strength improvement of alloys is contributed to solid solution strengthening and grain refinement strengthening by addition of Ta. Due to refinement of alloy microstructure and the increase of eutectic structure,fracture strain of alloy is increased.

• Molecular dynamics simulation of the effects of void defect on the tensile deformation behavior of single-crystal α-Fe

  Li Xiang, Yin Yihui, Zhang Yuanzhang, Li Jicheng, Li Hongxiang

  Available online:April 03, 2025  DOI: 10.12442/j.issn.1002-185X.20240692

  Abstract(6) PDF(1.24 M)(0)

  Abstract:In order to investigate further the effects of void defect on the plastic deformation behavior of α-Fe under tensile load, the molecular dynamic models of the α-Fe samples with the void defects are established and related simulations under uniaxial tension are carried out for a series of models in the void radius of 0 nm, 0.25 nm, 0.50 nm, 0.75 nm and 1.00 nm, respectively. The engineering stress-strain curve and the variations of crystal structure types and defects of each sample with tensile strain are obtained. The results show that overall, the deterioration of tensile mechanical properties of the sample with void is positively related to the void size. The larger the void size is, the easier it is for the sample to enter the plastic deformation stage. Overall, Young"s modulus, yield stress, ultimate tensile strength and tensile elongation of the samples containing void decrease with increasing of the radius of the void. The plastic deformation mechanism is of a mixture of the tensile stress-induced structural phase transition and the dislocation slip. However, the characteristics of stress-strain curves change significantly with increasing of the radius of the void, and the plastic yield stage and strain hardening stage of the sample become shorter, the strain hardening stage even vanishes. The research deepens the understandings of the effects of void defect on the plastic deformation mechanism of metals and lay a useful foundation for the subsequent analysis of the physical and mechanical properties of polycrystalline α-Fe materials.

• Effect of forging process and heat treatment on microstructure and mechanical properties of Er7050 aluminum alloy

  LiuYuhang, RongLi, HuangHui, ChenJiongshen, MaChenxi, Shixiaocheng, WeiWu, WenShengping, WuXiaolan, NieZuoren, GaoKunyuan

  Available online:April 03, 2025  DOI: 10.12442/j.issn.1002-185X.20240697

  Abstract(3) PDF(2.77 M)(0)

  Abstract:In order to explore the effect of multi-directional forging on the microstructure and mechanical properties of aluminum alloy, this paper takes the homogenized Er7050 aluminum alloy as the research object. The alloy was subjected to multi-directional forging of three different forging passes at 400 ° C, namely three-pier three-pull ( 3U3CS ), six-pier six-pull ( 6U6CS ) and nine-pier nine-pull ( 9U9CS ). Subsequently, the alloy was subjected to solid solution treatment, water quenching and T6 aging treatment. The microstructure and mechanical properties of the samples were analyzed. By comparing the mechanical properties of the samples obtained by three different forging processes, we found that the samples treated by the Jiudunjiuba forging process have the best mechanical properties, which is attributed to its fine grains and dense precipitated strengthening phases. The average tensile strength of the sample under this forging process is 621.4 MPa, the average yield strength is 545.4 MPa, and the average elongation is 13.10 %, which indicates that the optimized forging process significantly improves the mechanical properties.

• Finite element simulation and experimental analysis of Mg alloy processed by inverse temperature field equal channel angular pressing

  Meng Shuaiju, Song Jinlong, Chen Jianfei, Zhang Jianjun, Wang Lidong, Qi Jianing, Li Yongfei, Yang Guirong

  Available online:April 03, 2025  DOI: 10.12442/j.issn.1002-185X.20240699

  Abstract(8) PDF(1.06 M)(1)

  Abstract:Aiming at revealing the influence of mold temperature on the temperature field and effective stress field of Mg alloy processed by inverse temperature field equal channel angular pressing (ITF-ECAP), a thermal mechanical coupled finite element analysis model of Mg-1.5Bi (wt.%, B2) alloy ITF-ECAP processing was established. Combined with experimental research, the processing process of B2 alloy at different mold temperatures was analyzed. The results showed that during the ITF-ECAP processing, the temperature of the billet significantly increased at the corner of the mold channel, which facilitated smooth plastic deformation. After severe deformation, the temperature gradually decreased, effectively avoiding coarsening of recrystallized grains. The stress concentration area of the billet is mainly distributed at the corner of the channel and near the mold outlet, and it significantly decreases with the increase of mold temperature. The verification experiment found that when the mold temperature was low (200 ℃), the surface of B2 alloy billet cracked after one pass ITF-ECAP processing, while the surface of B2 alloy could be ITF-ECAP processed for 4 passes without surface cracks when the mold temperature was setted as 300 ℃. Further microstructural characterization revealed that a bimodal grain structure consisting of fine and ultrafine grains was formed in the B2 alloy processed by four-pass ITF-ECAP deformation.

• Study on microstructure and properties of WC-Co and WC-Ni-Fe cemented carbides with different binder phase contents

  zhangfan, yuandelin, yeyuwei, chenhao

  Available online:April 03, 2025  DOI: 10.12442/j.issn.1002-185X.20240712

  Abstract(6) PDF(1.38 M)(0)

  Abstract:Two groups of WC-Co and WC-Ni-Fe cemented carbides with varying binder contents were prepared using the same process. The research explored the trends in the microstructure changes and the differences in properties between WC-Co and WC-Ni-Fe cemented carbides, aiming to provide a novel perspective for the application and development of new cemented carbides in the mining tools industry. The results show that the binder phase of both WC-Co and WC-Ni-Fe cemented carbides exhibits a single-phase structure. As the binder phase content in the alloy increases, there is an increase in the average grain size and a decrease in hardness and coercive magnetic force. Additionally, cobalt magnetism, bending strength, and impact toughness all exhibit upward trends. In comparison, the WC-Co exhibits higher coercive cobalt magnetism, magnetic force, and bending strength than WC-Ni-Fe cemented carbide. However, WC-Ni-Fe cemented carbide exhibits better impact toughness with a higher binder phase content, reaching up to 5.9J/cm2. The frictional behavior of WC-Co and WC-Ni-Fe cemented carbides is similar, but the wear degree of the alloys gradually increases as the binder phase content increases. When comparing equal amounts of binder phase content, the wear resistance of WC-Co is superior to that of WC-Ni-Fe.

• Microstructure homogenization control of GH4706 alloy using hot deformation maps

  zhengdeyu, Yufeng Xia, zhoujie

  Available online:April 03, 2025  DOI: 10.12442/j.issn.1002-185X.20240716

  Abstract(5) PDF(1.97 M)(0)

  Abstract:Hot compression tests for GH4706 alloy were performed at a true strain of 1.2 within a temperature range of 950-1150 ℃ and a strain rate range of 0.001-1 s-1. The optimal hot deformation temperature and strain rate range were determined using nephogram maps for dynamic recrystallization (DRX) fraction, average grain size, and grain distribution standard deviation. Processing maps at true strains from 0.4 to 0.9 were generated based on flow stress curves to identify the strain corresponding to optimal microstructure homogenization efficiency at various temperatures and strain rates. Within the optimal parameter range, processing maps indicated that the true strain of 0.6 was the optimal microstructure homogenization efficiency at 1150 ℃ and 0.01 s-1. The grain orientation spread (GOS) maps obtained from the experiment confirmed this conclusion. This study provides an effective method for microstructure homogenization control of GH4706 alloy. Meanwhile, it can provide effective reference for the minimum strain threshold of the local part of the forging in engineering.

• A Review: Prospect on welding techniques of Zr Alloys

  baiyujie, liyuanxing, zhuzongtao, chenhui

  Available online:April 03, 2025  DOI: 10.12442/j.issn.1002-185X.20240724

  Abstract(3) PDF(1.51 M)(0)

  Abstract:In recent years, clean nuclear energy has developed rapidly. Zr alloys are commonly used as fuel element cladding materials in water-cooled nuclear reactions due to their good corrosion resistance and low neutron absorption cross-section. The nuclear fuel is usually sealed in a Zr alloy envelope by welding, so its weld quality is particularly critical. The high heat input of traditional fusion welding leads to large deformation, and the porosity and intermetallic compounds (IMCs) in the brazing process tend to damage the joint performance, and low-temperature diffusion bonding of Zr alloys can avoid the above problems. Therefore, this paper analyzed the weldability of Zr and its alloys, reviewed the research status of their welding technologies consisting of fusion welding, brazing, and diffusion bonding, briefly introduced two kinds of pre-welding optimization methods, namely surface mechanical attrition treatment (SMAT) and thermo-hydrogen processing (THP) and finally summarized and prospected their applications in low-temperature diffusion bonding of Zr alloys.

• Effect of Oxygen/Ar Flow Rate Ratio on the Properties of Amorphous Ga₂O₃ Thin Films on Flexible and Rigid Substrates

  Yuanjie Li, Yuqing Zhao, Chenyu Liang

  Available online:April 03, 2025  DOI: 10.12442/j.issn.1002-185X.20240726

  Abstract(3) PDF(1.70 M)(0)

  Abstract:In the present work, amorphous Ga₂O₃ (a-Ga₂O₃) thin films have been developed on both flexible polyimide(PI), rigid quartz glass and Si substrates via using radio frequency magnetron sputtering at room temperature. The effect of oxygen/Ar flow rate ratio on the structural, optical, surface morphology as well as chemical bonding properties of the a-Ga₂O₃ films was systematically investigated and elucidated. The average optical transmittance of the a-Ga₂O₃ films is over 80% from 300 to 2000 nm. The extracted optical band gap of the a-Ga₂O₃ films increases from 4.97 to 5.13 eV with increasing O₂/Ar flow rate ratio from 0 to 0.25, resulting from a suppression of oxygen vacancy defects as increasing O₂ partial pressure during growth. Furthermore, the optical refractive index and surface roughness of the a-Ga₂O₃ films have been optimized while the O₂/Ar

• Optimization Basis and Control of the Vacuum Induction Melting Process for Monel K-500 Alloy.

  Sun Panhe, Li Shu, Jiang He, Dong Jianxin

  Available online:April 03, 2025  DOI: 10.12442/j.issn.1002-185X.20240733

  Abstract(4) PDF(938.04 K)(0)

  Abstract:During the vacuum induction melting (VIM) casting process of Monel K-500 alloy, a large number of shrinkage defects are likely to occur in the upper part of the ingot, resulting in low yield and poor quality. To address this issue, this paper investigates the thermal and physical properties and solidification process of Monel K-500 alloy through thermodynamic calculations using JMat-Pro. The experimental results show that the solidification range of Monel K-500 alloy is between 1250°C and 1350°C; the solidification path is: L→L+γ→L+γ+MC→γ+MC+M7C3→γ"+γ+MC+M7C3; During the solidification process, as the percentage of the residual liquid phase decreases, Ni exhibits negative segregation, while Cu exhibits positive segregation. Combining the thermodynamic calculation results with a finite element (FEM) model, a simulation of the industrial vacuum induction melting casting process for 6 tons of Monel K-500 alloy was conducted. The simulated results were compared with the actual shape and size of the shrinkage defects in the upper part of the induction ingot to verify the reliability of the casting model. In addition, this paper explores the effects of different pouring parameters on shrinkage defects in the vacuum induction ingot based on the model. The results show that the addition of a riser has the most significant improvement on the shrinkage defects in the vacuum induction ingot. As the riser volume ratio increases, the volume of shrinkage defects in the ingot body decreases significantly, with no shrinkage defects present in the ingot body at a riser volume ratio of 20%. When the pouring speed is in the range of 2.5 kg/s-17.5 kg/s, the volume of shrinkage defects in the vacuum induction ingot decreases as the pouring speed decreases; however, below 7.5 kg/s, the shrinkage defects move inward within the ingot body.es; however, below 7.5 kg/s, the shrinkage defects move inward within the ingot body.

• Microstructure Evolution Characteristics and mechanical properties of a novel nitrogenous nickel-based deposited metal from gas metal arc welding to Heat Treatment

  Yingdi Wang, Guiqing Zhang, Taisen Yang, Xuewei Liang, Yunhai Su

  Available online:April 03, 2025  DOI: 10.12442/j.issn.1002-185X.20240744

  Abstract(5) PDF(1.49 M)(0)

  Abstract:Nitrogenous nickel-based deposited metal was prepared by gas metal arc welding. Subsequently, solid solution treatment as well as solution and aging treatments were carried out to study the evolution of microstructure and tensile properties in different states. The results show that the high temperature tensile strength of the deposited metal exhibits good performance with the addition of W and N. The grain size of the alloy is large and petal-like Laves phase appears at the grain boundaries. After solid solution treatment, the grain size decreased and the Laves phase disappeared. However, the yield strength and elongation of the deposited metal decreased. The grain size of the solid solution and aging treated samples was more uniform. Nanoscale M(C,N) phases precipitated within the crystals and M₂₃C₆ phase formed at grain boundaries. The yield strength and ultimate tensile strength were higher than the other samples, but the plasticity was the lowest. The main deformation mechanism is the unit dislocation a/2<110> cutting precipitation phase.

• Effect of charging temperature on hydrogen damage behavior of TA15 alloy

  Wu Chaomei, Wang Tiantai, Liu Jiaxin, Zhao Mingjiu

  Available online:April 03, 2025  DOI: 10.12442/j.issn.1002-185X.20240748

  Abstract(4) PDF(1.96 M)(0)

  Abstract:In this paper, the effect of charging temperature on the hydrogen damage behavior of TA15 alloy was studied. The results show that the strength of the alloy increases first and then decreases with the increase of charging temperature under the condition of 800K ~ 900K, 10MPa and 1h hydrogen charging, but the elongation decreases continuously. When the charging temperature is 800 K, the tensile strength of the alloy increases by 9 % compared with the as-received samples, while the elongation decreases by 12 %. When the charging temperature is 900 K, the tensile strength of the alloy decreases by 85 %, and the alloy is completely brittle fracture ( the embrittlement index reaches 100 % ). The microanalysis demonstrates that as the hydrogen charging temperature increases from 800 K to 900 K, the hydrides in the alloy undergo a transformation, shifting from precipitating predominantly along the α/β phase boundary to precipitating within the α and β phases. The sizes and quantities of these hydrides increased significantly, resulting in a change in the nature of the hydrogen cracking of the alloy. Rather than occurring along the α/β phase boundary, as previously observed, the cracking now occurs along the hydrides within the α and β phases or along the hydride/matrix interfaces.

• Shape topology optimization method for strain uniformity control of large disk forgings of superalloy

  Menghan Wang, Xin Li, Yuanyuan Zheng, Menglong Du, Songlin Li, Haicheng Zhang

  Available online:April 03, 2025  DOI: 10.12442/j.issn.1002-185X.20240756

  Abstract(5) PDF(1.10 M)(0)

  Abstract:Strain uniformity is an important index to evaluate the performance of large disk forgings in aerospace. Taking turbine disc as the research object, this paper explores the reasons for the formation of low strain zone of turbine disc forgings, and proposes a topological optimization design method suitable for large disc forgings based on the addition and removal rule of "number of subunits - volume - number of subunits". The method adopts the allocation of appropriate volume for each column element, and adapts the relative height of each region by stacking and adjusting modules. Obtain the shape of the preforging with low complexity of the target shape. In order to verify the effectiveness of the optimization method, the paper takes deformation uniformity as the goal to automatically optimize the shape of large turbine disc preforging. After optimization, the deformation uniformity of the forging is increased by 45%, and there is no strain dead zone. The results of numerical simulation and production test show the reliability of the method proposed in this paper.

• Effect of Sandblasting on Recrystallization Defects of Directional Solidification 4777DS Superalloys

  ZhangQiongYuan, ZhangZiYue, YangATao, YaoZhiHao, HeQunGong, WangHaiYang, DongJianXin

  Available online:April 03, 2025  DOI: 10.12442/j.issn.1002-185X.20240757

  Abstract(5) PDF(1.49 M)(1)

  Abstract:Nickel based superalloy 4777DS is used in turbine blades and other engine components due to its creep strength and oxidation resistance at high temperatures. Surface recrystallization can have adverse effects on the mechanical properties of alloys. The effects of different sand-blasting processes on recrystallization defects and the occurrence of recrystallization in 4777DS alloy were studied using optical microscopy and scanning electron microscopy. The analysis of the recrystallization structure on the alloy surface after sandblasting shows that the depth of recrystallization on the alloy surface increases with the increase of sandblasting intensity, time, gravel diameter, and the decrease of sandblasting distance. After sandblasting, the deformed sample showed that the γ "phase near the sandblasted surface changed from a butterfly shape to a long strip shape, and some of the deformed γ" phase surrounded the areas with greater deformation. At the same time, TEM observed a large number of dislocations distributed in the γ matrix channels and γ "phase. The different gamma "phases between dendrites affect the growth of recrystallization, resulting in the formation of wavy grain boundaries. No inhibitory effect of eutectic or carbide on recrystallization has been found. Due to the small size of surface recrystallized grains and the presence of residual stress, a new layer of recrystallized grains will form in the subsurface.

• Hot Deformation Behavior of New Heat-Resistant Alloy SP2215

  Liang Kai, Yao Zhihao, Fu Yingying, Wang Hongying, Zhang Longyao, Cheng Jian, Dai Weixing, Dong Jianxin

  Available online:April 03, 2025  DOI: 10.12442/j.issn.1002-185X.20240768

  Abstract(8) PDF(3.99 M)(0)

  Abstract:The SP2215 heat resistant alloy has been successfully utilized in the production of superheater/reheater pipes for ultra-supercritical thermal power units operating at temperatures ranging from 620 to 650℃, owing to its exceptional high temperature durability and corrosion resistance. However, there is still a lack of research on the hot deformation behavior of this alloy, which plays a crucial role in determining the subsequent deformation process and final quality of the steel pipe. In this study, a series of hot compression tests were conducted on the alloy using a Gleeble 3500 thermal simulation testing machine at temperatures ranging from 1100 to 1250℃ and deformation rates ranging from 0.01 to 10 s^-1 with a deformation amount of 50%. The influence of different deformation temperatures and rates on the rheological curve and deformation structure of the alloy was investigated. Furthermore, by modifying the rheological curve based on friction and temperature effects, we established thermal deformation Arrhenius constitutive model, Avrami dynamic recrystallization model, and Yada dynamic recrystallization average grain size model for SP22215 alloy. Additionally, Prasad-Murty-Malas hot working maps were constructed for alloys based on various rheological instability criteria. Our findings indicate that as the deformation temperature increases, the degree of work hardening decreases while dynamic recrystallization becomes more likely in SP2215 alloy. Moreover, higher strain rates result in increased flow stress and work hardening rate for this alloy. The lowest degree of recrystallization occurs at a strain rate of 1 s^-1; however, if not properly selected under certain conditions, mixed crystal phenomenon may occur easily in this alloy. Under experimental conditions considered here, the optimal thermal deformation window for SP2215 alloy is found to be between 1200 and 1250℃ with strain rates ranging from 5 to10 s^-1.

• Synthesis of Nickel powders by Hydrazine Hydrate Reduction of Nickel Hydroxide

  Zhang QianKun, Deng LiuKe, Zhao XinYue, Su KeXin, Cao DongCheng, Bai YouZhang, Wu Lian, Xiao YiFeng, Qian JingWen, HuangFu Ying

  Available online:April 03, 2025  DOI: 10.12442/j.issn.1002-185X.20240777

  Abstract(10) PDF(1.43 M)(0)

  Abstract:Fine nickel powders with a narrow particle size distribution was prepared by reducing nickel hydroxide in an aqueous solution. The study analyzed nickel powder formation and reduction pathways, discussing the effects of the molar ratio of hydrazine hydrate to nickel hydroxide, hydrazine concentration, and the amount of surfactant PEG6000 on particle size, surface morphology, and dispersion. X-ray diffraction (XRD), scanning electron microscopy (SEM), and laser particle size analysis revealed that nickel particle nucleation occurred on the nickel hydroxide surface, which gradually dissolved during the reaction. Increasing the molar ratio of hydrazine to nickel hydroxide initially decreased and then increased the nickel particle size. Higher hydrazine concentrations reduced particle size. A small amount of PEG6000 improved dispersion, while higher amounts preserved the morphology of nickel hydroxide. Adjusting the surfactant amount allowed control of the average particle size between 1-2μm.

• Study on the Performance of diesel particulate filter under Different catalyst loading

  Zhang Yunhua, Xu Yaoxin, Lou Diming, Fang Liang

  Available online:April 03, 2025  DOI: 10.12442/j.issn.1002-185X.20240778

  Abstract(2) PDF(702.79 K)(0)

  Abstract:Diesel particulate filter is an effective technology to reduce diesel particulate emissions, and its performance is closely related to catalyst loading. Based on the platform test system of heavy diesel engine, the influence of catalyst amount on the pressure drop, gas state and particulate emission reduction performance of diesel CDPF regeneration was studied. The results show that the exhaust back pressure of catalyst increases linearly with the increase of catalyst loading. When catalyst loading increases from 0 g/ft3 to 5, 10 and 20 g/ft3, the average exhaust back pressure increases from 2.94 kPa to 3.44,3.96 and 4.51 kPa, respectively. The higher the amount of catalyst, the better the emission reduction effect of the catalytic converter on CO and THC. When catalyst loading increases from 0 g/ft3 to 5, 10 and 20 g/ft3, CO emission decreases from 78.94×10-6 to 71.39×10-6, 68.12×10-6 and 63.30×10-6, and THC emission concentration decreases from 57.34×10-6 to 48.31×10-6, 46.93×10-6 and 44.51×10-6, respectively. The amount of catalyst had a significant effect on NO oxidation, but not on NOx emission concentration. CDPF can achieve a reduction rate of more than 95% for PM and PN. Increasing catalyst loading improves the particulate emission reduction effect of CDPF, with a more significant improvement in the reduction effect of nucleation particles. The results of this study have important reference value for the design of high-performance CDPF.

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  Effect of grain refinement on grain boundary diffusion process and magnetic properties of sintered NdFeB magnets