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(74) HTML(89) PDF(2.70 M)( 69)

  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(22) HTML(48) PDF(9.60 M)( 55)

  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(23) HTML(34) PDF(4.38 M)( 47)

  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(18) HTML(29) PDF(1.23 M)( 40)

  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(16) HTML(31) PDF(2.09 M)( 52)

  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

  Abstract(14) HTML(32) PDF(2.00 M)( 44)

  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(13) HTML(21) PDF(1.71 M)( 52)

  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(23) HTML(24) PDF(11.66 M)( 69)

  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(22) HTML(51) PDF(5.89 M)( 62)

  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(14) HTML(28) PDF(2.18 M)( 49)

  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(19) HTML(31) PDF(12.17 M)( 59)

  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(19) HTML(47) PDF(10.05 M)( 48)

  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(22) HTML(24) PDF(13.28 M)( 41)

  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(15) HTML(29) PDF(10.53 M)( 37)

  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(27) HTML(27) PDF(3.83 M)( 36)

  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(27) HTML(36) PDF(5.77 M)( 36)

  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(13) HTML(24) PDF(5.45 M)( 32)

  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

  Abstract(19) HTML(40) PDF(5.14 M)( 37)

  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(14) HTML(34) PDF(4.08 M)( 36)

  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(15) HTML(18) PDF(2.00 M)( 39)

  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(17) HTML(19) PDF(1.72 M)( 32)

  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(13) HTML(20) PDF(4.70 M)( 31)

  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

  Abstract(13) HTML(21) PDF(4.70 M)( 28)

  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(16) HTML(22) PDF(7.03 M)( 28)

  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(13) HTML(27) PDF(8.33 M)( 23)

  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(20) HTML(16) PDF(6.38 M)( 17)

  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(21) HTML(22) PDF(3.44 M)( 27)

  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(31) HTML(24) PDF(6.69 M)( 26)

  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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• Effect of Annealing Temperature on Microstructure and Properties of Nickel-based Powder Superalloy Formed by L-PBF

  Wang Yao, Ren Xiaona, Chen Zhipei, Ge Changchun

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240541

  Abstract(3) PDF(2.50 M)(0)

  Abstract:Different temperature annealing treatments were conducted on a laser powder bed melted FGH4096M nickel-based superalloy. The microstructure of the alloy was analyzed using SEM and EBSD, while tensile tests were performed to investigate the impact of the annealing process on the microstructural evolution and mechanical properties of the laser powder bed melted FGH4096M superalloy. The results revealed that as the annealing temperature increased, dendritic and columnar crystals gradually disappeared in the formed alloy, with a significant precipitation of γ" phase observed at an annealing temperature of 900℃. Additionally, there was a gradual increase in hardness value, along with an upward trend in both tensile strength and yield strength; however, fracture elongation rate remained low at only 5%. Analysis of grain orientation difference distribution indicated that annealing could partially eliminate residual stress. These research findings provide valuable data support for enhancing the performance of laser powder bed melted nickel-based superalloys.

• Static recrystallization kinetics of the metal beryllium

  Xu Demei, Li Meisui, Li Zhinian, Ye Shupeng, He Lijun, Li Feng

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240551

  Abstract(3) PDF(9.72 M)(0)

  Abstract:The microstructure evolution and the kinetics of static recrystallization have been investigated in beryllium during annealing at 680 ℃-880 ℃ through the implementation of the isothermal compression test and the measurement of the recrystallized fraction by hardness. The beryllium was subjected to compression on an Instron 5582 testing machine under varying strain temperatures (250 ℃-450 ℃), strain rates (10-1 s-1 to 10-4 s-1), and true strains (16%-92%). The results show that decreasing the strain temperature and increasing the strain rate promotes the progress of beryllium recrystallization. As the strain is increased, the beryllium recrystallized grains exhibit refinement, and the recrystallization rate is accelerated. However, the effect of increasing the strain on improving the recrystallization rate of beryllium diminished when the strain was increased to more than 60%. Increasing the annealing temperature, the recrystallization rate of beryllium was significantly accelerated. In particular, when the annealing temperature is elevated from 750 ℃ to 780 ℃, the recrystallization rate of beryllium enhances dramatically. At 880 ℃, the time for beryllium to complete recrystallization is reduced to approximately five minutes. The static recrystallization activation energy of beryllium is 396.56 kJ/mol at 680 ℃-750 ℃, while it is only 72.93 kJ/mol at 780 ℃-880 ℃. A static recrystallization kinetic model of beryllium with a modified Avirami component n is constructed. The calculated values of the model are in good agreement with the experimental values, indicating that the model is capable of predicting the static recrystallized fraction of beryllium deformed at low temperatures (250 ℃-450 ℃) and meets the requirements of engineering applications.

• Dynamic Recrystallization Behavior and Microstructure Evolution of GH4710 Alloy Prepared by Ingot Extrusion

  Chen Youhong, Lan Bo, Lin Yingying

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240555

  Abstract(4) PDF(4.82 M)(0)

  Abstract:The dynamic recrystallization (DRX) behavior and microstructure evolution of the as-extruded GH4710 alloy were investigated through isothermal compression experiments and quantitative metallographic analysis. The study was conducted at temperatures ranging from 1050 to 1120 °C and strain rates ranging from 0.01 to 5 s_^-1. True stress-strain curves, average grain size, and DRX volume fraction data were obtained under various deformation conditions. Model for the DRX volume fraction and grain size of the as-extruded GH4710 alloy have been established using a statistical regression method. The developed model was implemented in the Derform-3D software, and isothermal compression simulations were conducted using the finite element method (FEM). The simulation results of the isothermal compression experiments have verified the accuracy of the model. Subsequently, a simulation of a turbine disk forging was conducted using the model to determine the optimal process parameters by analyzing the results of the simulation. The comparison revealed a strong correlation between the simulated results and the actual microstructure of the turbine disk forged with the optimal process parameters. Therefore, the established DRX model serves as a fundamental reference for understanding the microstructure evolution during the as-extruded GH4710 alloy hot-deformation process.

• Study of ultra-precision polishing of outer surface of tube using a magnetic compound fluid wheel

  Wang Youliang, Jiang Zhe, Zhang Wenjuan, Yin Xincheng, Liang Bo

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240558

  Abstract(1) PDF(3.46 M)(0)

  Abstract:The stainless steel tube are widely used in aviation, medical treatment due to the corrosion resistance properties. In this study, a novel method employing a magnetic compound fluid (MCF) wheel was proposed for polishing the outer surface of stainless steel tube. Firstly, a polishing apparatus was constructed, in addition, the distribution of magnetic field of MCF wheel on the workpiece surface was explored by Maxwell software and Tesla meters, and the relationship between magnetic field distribution and material removal on the workpiece surface was investigated. Then, a material removal (MR) model was established and proved by the experimental results under the given conditions. Finally, The influence laws of carbonyl iron powder particle size d_CIP, abrasive particle size d_AP, magnet speed n_m, workpiece speed n_c and supply of MCF V on surface roughness Ra and reduction rate Ra% were investigated through experiments, and the mechanism of different parameters on surface quality was explored. The results show that the magnetic induction intensity during polishing is positively correlated with the polished profile of the workpiece. The trend of MR simulation is consistent with the experimental value, which prove the MR model is accurate. The smoothest surface of stainless steel tube can be achieved wherein the revolution speed of the magnet and workpiece (n_m = 200 rpm, n_c = 5000 rpm), amount of MCF slurry(V = 2 mL) were given using MCF containing carbonyl iron powder (15 μm) 50 wt. %, abrasive particle (7 μm) 12 wt. %, α-fiber 3 wt. %, magnetic fluid 35 wt. %. The final surface roughness decreased from 0.411μm to 0.007μm after 100 min polishing, the reduction rate is 98.297%, which demonstrated that this novel method is appropriate for polishing outer surface of tube.

• Study on erosion resistance and damage evolution of Ti-doped Ta₂O₅ high transmittance coatings

  Ye Borui, Chao Rui

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240563

  Abstract(10) PDF(1.86 M)(0)

  Abstract:In order to verify the wear resistance and erosion resistance of Ti-doped Ta₂O₅ coating (TTO), a series of TTO coatings were prepared by magnetron sputtering technology by controlling the power of Ti target. The growth structure, microstructure and tribological properties of TTO coatings with Ti target power were studied. After the erosion test, the variation of erosion damage behavior of TTO coatings with mechanical properties under different erosion conditions was further studied. The results show that the TTO coatings eliminates the roughness, voids and defects in the material due to the mobility of the adsorbed atoms during the growth process, and a flat and dense smooth surface is obtained. Tribological tests show that the TTO coatings is mainly characterized by plastic deformation and micro-crack wear mechanism. Higher Ti target power can improve the wear resistance of TTO coatings. The results of the erosion test show that the impact crater, furrow, micro-cutting, brittle spalling and crack formation are the main wear mechanisms of the TTO coatings samples under erosion.

• Investigation on the heterogeneous deformation behavior and strain rate sensitivity of the metastable β-Ti-1023 alloy

  wangxueli, lifuguo, jiapenglai, zhangzhimin, wangqiang

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240576

  Abstract(9) PDF(13.09 M)(13)

  Abstract:The digital image correlation (DIC) technology has been used to track promptly the strain distribution and local strain evolution under different strain rates in this paper, and the propagation behavior of strain distribution and its strain rate sensitivity have been investigated. And the electron backscatter diffraction (EBSD) has been selected to analyze the microstructure evolution, the distribution of stress induced α" martensite transformation (SIMT) and martensite twinning after deformation. Besides, the scanning electron microscope (SEM) has been adopted to observe the fracture morphology of the material. The following conclusions can be drawn: (1) The strain distribution evolved from an approximate uniform distribution to a non-uniform distribution, then showing a phenomenon of strain concentration, and ultimately occurring fracture in the strain concentration area, and the significanted necking phenomenon has been displayed at the low strain rates. (2) A clear double yield phenomenon has been exhibited in the stress-strain curves with producing higher strain hardening rates at the low strain rates, it means that the materials show a negative strain rate sensitivity effect. (3) The content of α" martensite increased significantly, the grain size refined obviously, and the average values of KAM (Kernel average misorientation) and GNDs (Geometrically necessary dislocations) increased dramatically with the strain rate decreasing, it indicates that the SIMT increase can contribute to the accumulation of dislocation density in the deformed sample and be more conducive to the coupling effect of multiple plastic deformation mechanisms. (4) The fracture morphology mainly occur tensile fracture by the aggregation of ductile dimples and voids. The stress on the dimples rapidly develops from unidirectional tension to triaxial tension resulting in sufficient growth of the dimples during the deformation process. Therefore, the ductile fracture characteristics dominated in the low strain rates deformation with promoting the occurrence of this phenomenon.

• Application Research of Nanofibrous LSCF@GDC Composite Cathode in Reversible Solid Oxide Fuel Cells

  Sun Xu, Zhang Bingqi, Zhao Jingqi, Sun Yue, Liu Xin, Zhou Hongyang

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240581

  Abstract(9) PDF(1.74 M)(0)

  Abstract:Reversible solid oxide cells (RSOCs) can theoretically achieve a relatively high energy conversion efficiency. The key to its widespread application is to further enhance the current density so as to increase hydrogen production and output current. However, insufficient catalytic activity of the oxygen electrodes has become an obstacle to the application of reversible solid oxide cells. The paper successfully fabricates composite LSCF@GDC nanofibers with reversible oxygen evolution and reduction electrocatalytic activity by employing electrospinning technology. Compared with the oxygen electrodes materials synthesized by the traditional sol-gel method, the three-dimensional nanofiber structure oxygen electrodes described greatly reduces the battery polarization impedance, increases the discharge power density and electrolytic current density, and shows better reversibility and stability in long-term tests. The research confirms the advantage of electrode morphology engineering control in expanding the catalytic interface and reaction sites.

• Corrosion resistance enhancement of GH3625 alloy tube in high-temperature KCl-MgCl₂ molten salt environment via Microstructure tailoring

  Gao Yubi, Wang Xin, Zhen Bing, Xu Jiayu, Ding Yutian

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240588

  Abstract(1) PDF(9.52 M)(1)

  Abstract:The influence of microstructure with different ratios of twin boundaries on the corrosion behavior of GH3625 alloy pipes in high-temperature (600 ℃~800 ℃) KCl-MgCl₂ molten salt was studied using EBSD, XRD, SEM, and EDS methods. The results showed that with the increase of annealing temperature, the proportion of annealing twin boundaries in the equiaxed grains of GH3625 alloy tube increased, and the higher the proportion of twin boundaries in the alloy at the same corrosion temperature, the better its high-temperature resistance to KCl-MgCl₂ molten salt corrosion. Meanwhile, as the corrosion temperature increases, the high-temperature resistance of the same group of samples to KCl-MgCl₂ molten salt corrosion decreases. In addition, under the same grain size conditions, the higher the proportion of annealing twin boundaries in GH3625 alloy tubes, the better their high-temperature resistance to KCl-MgCl₂ molten salt corrosion. This is mainly attributed to the high-density stable annealing twin boundaries themselves have excellent corrosion resistance, and the triple junction containing twin boundaries breaks the connectivity of the original high angle grain boundary network, suppressing the corrosion of the grain boundaries.

• Anisotropy Control of Titanium Alloy Porous Materials Based on the Modified Gibson-Ashby Model

  Ding Chao, Xie Tenglong, Xu Shenghang, Huang Minghao, Zhang Zhaoyang, Yang Xin, Tang Huiping, Zhao Yang

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240596

  Abstract(12) PDF(1.91 M)(0)

  Abstract:According to the varying load in different directions, the anisotropy control of porous materials can significantly enhance the load-bearing efficiency of materials, thus better addressing the need for lightweight designs. In this paper, a modified G-A model for srtut-based porous materials accounting for the geometric parameters was established by taking G7 and BCCZ types of TC4 porous materials as examples. This model could serve as a guide for the precise control of anisotropy for strut-based porous materials. By adjusting the geometric parameters of common unit cells, a range of anisotropic porous materials with similar configurations but distinct properties were created. The influence of cellular geometric parameters on the anisotropic mechanical properties and failure modes of these materials was investigated through both vertical and lateral compressive tests, which also validated the efficacy of our modified model. The research results indicated that the mechanical properties of strut-based porous materials were primarily determined by the aspect ratio and the inclination angle of their struts. By fine-tuning the inclination angle of these struts, the anisotropic mechanical properties of the porous materials can be effectively modulated. At identical density levels, it could result in a substantial increase in the vertical compressive strength of G7 and BCCZ types of TC4 porous materials by 105% and 45%, respectively, with only a minor reduction in lateral compressive strength of 16% and 13%, by increasing the inclination angle of the diagonal struts from 35° to 55°.

• Study on hot cracking sensitivity of Wrought superalloy GH4975 with high alloying

  ZHU Xing, JIANG He, DONG Jianxin, WAN Zhipeng

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240603

  Abstract(2) PDF(7.66 M)(0)

  Abstract:In order to study the hot cracking sensitivity of high alloying refractory superalloy GH4975, the crack morphology and microstructure characteristics of the ingot of GH4975 were observed, and the causes of hot cracking were analyzed by means of solidification behavior and thermodynamic calculation. The results show that the crack spreads along grain boundaries and dendrites, and the equiaxed crystal region has a greater tendency to crack than the columnar crystal region. Shrinkage holes are easy to appear in the center of the ingot. The formation of continuous shrinkage holes leads to insufficient overlap between dendrites, which is easy to be pulled apart under the action of stress to form a crack source. At the same time, the segregation of Al, Ti and Nb elements between dendrites is serious, and complex precipitates, especially a large number of (γ+γ ") eutectic phases, promote the nucleation and propagation of cracks. JMatPro"s calculation shows that GH4975 alloy has a large shrinkage rate in the solid-liquid two-phase zone and a wide range of non-complementary temperature, which is easy to form a shrinkage hole and become a crack source. Meanwhile, the linear expansion coefficient of the alloy changes greatly in the non-complementary temperature range, and the crack is easy to expand.

• Effect of Temperature on the Interface Microstructure andMechanical Properties of AZ31/Al/Ta Composites Prepared by Vacuum Hot Compression Bonding

  Yu Zhilei, Li Jingli, Han Xiuzhu, Li Bairui, Xue Zhiyong

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240604

  Abstract(8) PDF(1.80 M)(0)

  Abstract:The Mg/Ta composite material exhibits both exceptional resistance to high-energy particle irradiation and lightweight characteristics, enabling it to more effectively address the requirements of future deep-space exploration. However, joining these two dissimilar metals is challenging due to their significant differences in properties. In this work, AZ31/Al/Ta composites were successfully prepared using the vacuum hot compression bonding (VHCB) method. The effect of hot compressing temperature on the interface microstructure evolution, phase constitution, and shear strength at the interface was investigated. Moreover, the interface bonding mechanisms of the AZ31/Al/Ta composites under the VHCB process conditions were explored. The results demonstrated that as the VHCB temperature increased, the phase composition of the interface between Mg and Al changed from the Mg-Al brittle IMCs (Al12Mg17, Al3Mg2) to the Al-Mg solid solution. Meanwhile, the width of the Al/Ta interface diffusion layer increased to 450℃ compared to that at 400℃. The shear strengths were 24 MPa and 46 MPa at 400℃ and 450℃, respectively. The interfacial bonding mechanism of AZ31/Al/Ta composites involves the coexistence of diffusion and mechanical meshing. Avoiding the formation of brittle phases at the interface can significantly improve interfacial bonding strength.

• Study of Electric Parameters to regulate Corrosion Resistance of MAO Coating on TC4

  Wang Sheng, Zhang Yali, Liu Haoming, Liu Yuchang, Wang Haoxu, Ma Ying, Li Yuandong

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240609

  Abstract(8) PDF(1.33 M)(0)

  Abstract:This paper investigates the effects of voltage, pulse frequency, duty cycle and processing time on the corrosion resistance of micro-arc oxidised TC4 titanium alloy coatings using polar analysis of variance (ANOVA), with a subsequent objective of exploring the significance relationship and the optimum combination of the factor levels of the electrical parameters. Concurrently, an investigation was conducted into the mechanisms through which electrical parameters influence the corrosion resistance of the film layer, with a particular focus on its morphology and physical composition. A regression equation is established to facilitate regulation of the corrosion resistance properties of micro-arc oxidized films through manipulation of electrical parameters. The findings indicate that the duty cycle exerts the most significant influence on the electrochemical corrosion resistance of the membrane layer, the next most influential factors are pulse frequency and voltage, processing time was observed to have a comparatively lesser effect. The duty cycle and pulse frequency influence both structure and performance characteristics of the film layer by altering arc ignition discharge duration as well as arc quenching cooling times. An increase in voltage, duty cycle, processing time, or a decrease in pulse frequency can result in an enhanced power output from the power supply, this leads to an increase in film thickness along with larger pore sizes within microporous structures while reducing densification. Additionally, it promotes more efficient generation of Al2TiO5 within the film layer, however, this ultimately results in diminished electrochemical corrosion resistance. The results of the correlation coefficient testing demonstrate a strong relationship between the dependent and independent variables within the established regression equation. This finding provides theoretical support for predicting methods aimed at regulating performance characteristics in titanium alloy micro-arc oxidation films.

• Ammonium tungstate evaporation crystallization purification based on single factor combined with Box-Behnken method

  Xiao Lairong, Li Shaohao, Zhao Xiaojun, Wang Xinyue, Wang Zihao, Cai Zhenyang, Lu ekang, Liu Sainan, Li Qingkui

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240615

  Abstract(2) PDF(1.31 M)(0)

  Abstract:The single factor + Box-Behnken response surface method was used to optimize the impurity removal process of ammonium tungstate solution evaporation crystallization method to prepare higher purity ammonium paratungstate (APT). Firstly, in order to reduce the total content of four impurities (Na, K, S, Mo elements) in APT, the preferred range of crystallization temperature, stirring speed and initial concentration of ammonium tungstate solution was preliminarily determined by single factor method. Secondly, the evaporation crystallization impurity removal process of APT was further optimized by Box-Behnken response surface method, and the mutual influence of three factors on the total amount of four impurities in APT was studied. The results show that the order of influence of three factors on the total amount of four impurities is : initial concentration of ammonium tungstate solution > evaporation temperature > stirring speed ; the optimum process conditions were as follows : evaporation temperature 94 °C, stirring speed 1.25 m/s, initial concentration of ammonium tungstate solution 73 g/L. Under the experimental conditions, the total content of the four impurities in the prepared APT was reduced to 39.351 ppm, and the relative error with the optimal prediction value of the response surface method model was only 4.110 %, and the purity of APT reached 4N. The generated APT crystal is a columnar cuboid morphology with a small amount of broken crystals. The layered structure is obvious, the particle size distribution is uniform, and the grain refinement is obvious.

• New opportunities in refractory niobium alloys via additive manufacturing：A review

  Lan Hang, Lu Kaiju, Tong Yonggang, Wang Jie, Qiao jinjin, Chen Yongxiong, Hu Zhenfeng, Liang Xiubing

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240617

  Abstract(2) PDF(2.96 M)(0)

  Abstract:Due to their low density, good room-temperature plasticity, and excellent high-temperature toughness, refractory niobium alloys have been used in hot-end components in the aerospace field. However, niobium alloys prepared by traditional casting methods are difficult to process parts with complex geometries, and met problems like long processing period, expensive price and high buy-to-fly ratio. The rapid development of additive manufacturing technology in recent years not only reduces the production period and cost, but also obtains superior mechanical properties, which brings new opportunities for the further application of niobium alloys. To this end, this paper reviews the current state-of-art research on additively manufactured niobium alloys, focusing on the laser and electron-beam additive manufacturing of two generations of typical niobium alloys, namely C-103 and Nb521, in particular with regard to the modulation of their mechanical properties and microstructure. In addition, common types of niobium alloys and additive manufacturing methods are briefly introduced. Finally, the future direction of additively manufactured niobium alloys and the problems that still need to be solved are proposed. By reviewing the field of additively manufactured niobium alloys, this paper provides a reference for the further application of niobium alloys in the aerospace field for hot-end components of complex structures.

• Fracture Behavior of High Cycle Fatigue of Nickel-based Single Crystal Superalloys at 850 ℃

  zhangjingang, liuxinling, chenxing, lizhen, liujiabin, tengpeng, liuchangkui

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240631

  Abstract(4) PDF(3.32 M)(0)

  Abstract:Study on the high cycle fatigue fracture characteristics and damage mechanism of nickel based single crystal superalloys at 850 °C. The results indicate that high cycle fatigue cracks in single crystal superalloys generally originate from defect locations on the subsurface or interior of the specimen at 850 °C. Under the condition of stress ratio R=0.05, as the fatigue load decreases, the high cycle fatigue life gradually increases. The high cycle fatigue fracture is mainly characterized by octahedral slip mechanism. At high stress and low life, the fracture exhibits single or multiple slip surface features. Some fractures originate along a vertical small plane and then propagate along the {111} slip surface; At low stress and high lifespan, the fracture surface is prone to alternate and expand along multiple slip planes after originating from subsurface or internal sources, exhibiting characteristics of multiple slip planes. Through electron backscatter diffraction analysis and transmission electron microscopy analysis, it is known that there is oxidation behavior on the surface of the high cycle fatigue fracture, and the fracture section is composed of polycrystalline layer, distortion layer, and matrix layer from the outside to the inside. Among them, the main components of the polycrystalline layer are Ni and Co oxides; The distortion layer is mainly distributed in the form of elongated or short rod-shaped Al, Ta, and W oxides; The substrate layer is a single crystal layer.

• Study on the creep fracture mechanism of a new nickel-based single crystal superalloy

  Xiangfeng Liang, Jili Wu, Xizhou Kai, Yong Dai, Shi Cangkun, Yutao Zhao

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240632

  Abstract(11) PDF(3.06 M)(0)

  Abstract:In this paper, through the creep performance test, microstructure morphology observation and composition analysis of a new type of nickel-based single-crystal superalloy under the condition of 1100°C/140 MPa, the variation characteristics of the creep rate and the evolution characteristics of the microstructure before and after creep during the creep fracture process of the alloy were investigated, and the creep fracture mechanism of the new nickel-based single-crystal superalloy was revealed. The results indicate that the creep life of the alloy is 104.5 h, the strain can reach 33.58%, the creep rate decreases first and then increases, and finally tends to be stable until fracture. At the initial stage of creep, the creep rate shows a phenomenon of decreasing first, then rising and then decreasing again with time. Furthermore, the creep fracture microstructure is composed of dimples and tearing edges, without obvious slip planes. Oxides and recrystallized structures exist inside the fracture surface, and the voids inside the fracture are elongated and perpendicular to the stress axis, showing a fracture mechanism of microcrack accumulation.

• Microstructure and properties of ZrC nanoparticles strengthened WNiFe alloys

  Yang Run, Wang Hui, Liu Rui, Wu Xuebang, Wang Xianping, Fang Qianfeng, Liu Changsong

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240635

  Abstract(3) PDF(4.74 M)(0)

  Abstract:Tungsten (W) is one of the most promising plasma-facing materials in nuclear fusion devices and candidate target materials for spallation neutron source, however its applications are greatly hindered by its room-temperature brittleness and irradiation-induced embrittlement. W heavy alloys with room temperature ductility and low cost were considered as alternative materials. In this work, 93W-4.9Ni-2.1Fe alloys strengthened by nanoscale ZrC particles were fabricated by spark-plasma-sintering (SPS) and hot rotary swaging, respectively. The addition of a small amount of ZrC nanoparticles can refine grain size and increase the hardness of the WNiFe alloys, but hinder the formation of the γ-(Ni, Fe) phase during SPS. The SPS WNiFe and WNiFe-ZrC alloys are brittle at room temperature, while the swaged WNiFe and WNiFe-0.5 wt% ZrC alloys are ductile at room temperature. At 400 °C, the swaged WNiFe-0.5 wt% ZrC alloy exhibits both higher tensile strength and better ductility than the swaged WNiFe. The nanoscale particles distributed in the W grains and γ-(Ni,Fe) phase provided a good pinning effect and enhanced the strength. The thermal conductivity of swaged WNiFe-0.5 wt%ZrC is 71 Wm-1K-1 at room temperature, but it increases to about 100 Wm-1K-1 at 800 °C, which is close to that of pure W (121 Wm-1K-1). These results show the potential of WNiFe alloys as candidate materials for fusion applications.

• Research on BJ3DP and sintering densification of AlTiCrNiCu low-density high entropy alloy prepared by mechanical alloying

  Zhu Dezhi, Chen Haipeng, Cai Liangfu

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240636

  Abstract(3) PDF(2.11 M)(0)

  Abstract:The binder jetting 3D printing (BJ3DP) process is currently a research hotspot. Generally, the powder bed printing process requires spherical powders, which limits the preparation and printing of some HEA powders with large melting point differences. This study mainly focuses on the BJ3DP printing-sintering behavior of non-spherical particles. The results showed that the near-spherical AlTiCrNiCu low-density HEA powder with BCC structure was prepared by mechanical alloying, with a particle size ranged from 6.72 to 67.52 μm and an average particle size of 21.17 μm, which met the requirements of the BJ3DP printing process. The results of the orthogonal experiment indicate that when the binder saturation is 60%, the layer thickness is 120 μm, and the powder feeding speed is 15 pps, the green density of BJ3DP printing is the highest (about 44.7%). After sintering at 1190℃ for 4 hours, the density of the green body reaches 91.6%. The AlTiCrNiCu low-density HEA has a multiphase structure, with the B2 phase as the matrix, including BCC, FCC, and a small amount of L2₁ phase. The AlTiCrNiCu low-density HEA has high compressive properties, with a yield strength and compressive strength of approximately 840 MPa and 960 MPa, respectively. The research results provide ideas and reference for the BJ3DP printing and sintering of non-spherical metal powders, further expanding the application scope of metal powder BJ3DP printing and forming.

• Non-uniform Microstructure and High Temperature Coordinated Deformation Behavior of 2A97 / 5A06 Dissimilar Aluminum Alloy Friction Stir Butt Welded Plate

  Qin Zhonghuan, Wu Aiping, Yin Hongliang, Li Baoyong, Liu Qi, Wu Yong

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240637

  Abstract(4) PDF(2.83 M)(0)

  Abstract:In this paper, the non-uniform microstructure and high temperature coordinated deformation behavior of 2A97 / 5A06 dissimilar aluminum alloy friction stir welded plate were studied. The microstructure of each area of the welded joint was observed, and the high temperature mechanical properties of each area and the whole joint was studied. It was found that the grains in the weld nugget zone of 2A97 and 5A06 were fine. The grain size of each region on the 2A97 side was small and basically close, and the grain size of each region on the 5A06 side was slightly larger and the difference was obvious. Under the process parameter of 430 °C and 10_-3 s_-1^{, the} high temperature properties of 2A97 and 5A06 base metals are better, and the elongations are 278.8 % and 118.6 %, respectively. The strength and elongation of the nugget zone of the joint are 18.4 MPa and 176.1 %, respectively, which are between 2A97 and 5A06. The strength is about 2 times that of the 2A97 base metal, and the elongation is about 1.5 times that of the 5A06 base metal. The overall performance shows an obvious superposition principle. The deformation resistance of each region is different. The vertical weld specimen fractured after concentrated deformation in the 2A97 thermo-mechanically affected zone. After correction, the flow stress was slightly higher than that of the base metal and the elongation was close to that of the base metal. The grain size and flow stress of each region after welding meet the creep equation. The smaller the grain size, the lower the flow stress.

• An effective mechanical constitutive model for the fission gas bubbles in irradiated U-10Mo fuels

  Li yong, Yan feng, Zhang jing, Zang li ye, Ding shu rong

  Available online:April 10, 2025  DOI: 10.12442/j.issn.1002-185X.20240640

  Abstract(1) PDF(1.28 M)(0)

  Abstract:The bubble pressure of the fission gas bubbles (FGBs) in irradiated nuclear fuels causes mechanical interaction between the FGBs and the surrounding fuel skeleton. To calculate the micromechanical stress fields of the irradiated nuclear fuels with pressured FGBs, an effective mechanical constitutive model for the FGBs is deduced and verified based on the modified Van der Waals equation and the effect of the surface tension. Based on the established model, the micromechanical fields of irradiated U-10Mo fuels with randomly distributed FGBs during the uniaxial tensile test are calculated by finite element (FE) method. The macroscopic elastic constants of the irradiated U-10Mo fuels are obtained according to the homogenization theory, and the effects of bubble pressure, bubble size, and porosity on the macroscopic elastic constants are investigated. The conclusions can be drawn that: (1) The bubble pressure of the FGBs is balanced by the constraint stress of the surface tension and the surrounding fuel skeleton. The constraint stress of the surrounding fuel skeleton is determined by its deformation states, not equal to the hydrostatic pressure of the surrounding fuel skeleton or that of the macroscopic material points of fuel elements; (2) Adjacent FGBs exist stress interference and are prone to result in stress concentration in the surrounding fuel skeleton; (3) The macroscopic elastic constants of irradiated U-10Mo fuels decrease with macroscopic porosity according with the Mori-Tanaka model, while bubble pressure and size have insignificant effects on the macroscopic elastic constants of irradiated U-10Mo fuels.

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