Ti-1100 alloys with varying Yb₂O₃contents were prepared by melting-casting method.The mi-crostructural evolution of the alloys were observed by field emission scanning electron microscopy,and the mechanical properties were analyzed through isothermal compression tests conducted on an electronic uni-versal testing machine.The results indicate that the addition of Yb₂O₃can significantly reduce the grain size of Ti-1100 alloy,the spacing betweenα-lamellae in the grains is smaller,and the distribution ofαla-mellae is denser.With the increase of Yb₂O₃content,the grain size of the alloy decreases first and then in-creases,and the strength initially increases before decreasing.When the Yb₂O₃content reaches 0.45%,the alloy exhibits the minimum grain size and maximum strength.

The forged Ti₂AlNb-based alloy was taken as the research object,and the effects of solid solution time(1.5~6 h)at 950℃on the microstructure and room temperature tensile mechanical properties of the alloy were studied.The results indicate that solid solution time does not change the phase composition of the alloy.As the solid solution time increases,the average grain size of equiaxedα₂/O phase first increases and then decreases,with a more uniform distribution.The average thickness of the Rim-O phase shows an increasing trend.Under 6 h solid solution treatment,the equiaxedα₂/O phase grain shape becomes irregu-lar,and the O phase precipitates and coarsens in the B2 grain.As the solid solution time prolongs,the me-chanical properties of the alloy show a downward trend as a whole.The alloy with the solid solution time of 1.5 h has the best room temperature mechanical properties,with tensile strength of 896 MPa,yield strength of 795 MPa and elongation at break of 8.48%.

TC11 titanium alloy was selected as the test material,the effects of annealing temperature on the microstructure,crystal structure and fracture properties of TC11 titanium alloy were studied.The results show that with the increase of annealing temperature,the microstructure type of the alloy changes from bimodal structure to fine lamellarβtransformation structure,the fracture toughness increases continuous-ly,the number of dimples in the fracture morphology decreases continuously,and finally a brittle fracture morphology with rock-like characteristics is formed.When the annealing temperature is in the two-phase region,the{0001}crystal plane of the alloy shows a mixed texture of B-type and near-T-type.When the annealing temperature is in the single-phase region,the{0001}crystal plane of the alloy mainly exhibits T-type texture.With the increase of annealing temperature,the texture intensity increases continuously,but only the characteristic diffraction peaks ofαphase exist in the XRD patterns,and no diffraction peaks ofβphase or other phases are found.

日前,长沙有色冶金设计研究院有限公司(简称长沙有色院)创新研发的超深井绿色安全膏体充填新技术成功攻克多项行业核心难题,实现了超深井膏体安全自流输送和复杂环境下岩移有效控制,显著提升了深部矿山的绿色开发水平。经中国有色金属工业协会认定,该技术整体达到国际领先水平,为全球深部矿山开采树立了新的技术标杆。

To enhance the mechanical properties and electrical conductivity of Cu-Cr-Zr alloys and meet the requirements of new infrastructure for materials,this paper investigated the effects of single rare earth Ce,Y content and the mass ratio of mixed rare earth Ce/Y on the microstructure,mechanical properties,elec-trical conductivity and phase composition of Cu-0.8Cr-0.2Zr alloy.The results show that when single rare earth is added,with the increase in the content of rare earth Ce or Y,the microstructure of as-cast alloy first refines and then coarsens,and the hardness and electrical conductivity first increase and then decrease,with Y having a better effect than Ce on refining the microstructure and improving the hardness and elec-trical conductivity of the alloy.After adding mixed rare earth,the refinement effect of as-cast alloy micro-structure is better than that of adding single rare earth,but the hardness and electrical conductivity are lower than those of single rare earth alloy.The electrical conductivity of the alloy is higher when the Ce/Y mass ratio is higher,and the microstructure refinement effect and hardness of the alloy are better when the Ce/Y mass ratio is lower.Compared with as-cast alloy,rolling heat treatment further improves the micro-structure refinement,electrical conductivity and mechanical properties of the alloy.After rolling heat treat-ment,the alloy containing 0.5% Y has the best hardness and tensile strength,which are 132.38 HV and 485.33 MPa,respectively.The alloy containing 0.25% Ce and 0.25% Y has the best electrical conductivi-ty,which is 81.08% IACS.This study is beneficial for promoting the efficient and balanced utilization of Bayan Obo minerals and provides ideas for the industrial production and performance optimization of Cu-Cr-Zr alloy.

To achieve the uniform dispersion of the hard phase and the metallic binder of cemented car-bides,Co nanoparticles were uniformly coated on the surface of WC particles by the method of chemical co-precipitation followed by hydrogen reduction using CoCl₂·6H₂O and(NH₄)₂C₂O₄·H₂O as raw materi-als.The effects of chemical co-precipitation process parameters on the precipitation rate and the distribu-tion uniformity of WC-CoC₂O₄·2H₂O precursor powder were studied.WC-Co composite powders with different Co contents were pressed and sintered into cemented carbides.The effects of preparation methods of WC-Co composite powders(chemical co-precipitation-hydrogen reduction vs.manual mixing)and Co content on the metallographic microstructure and mechanical properties of cemented carbides were studied.The results show that the optimized process parameters of chemical co-precipitation are as follows:reac-tion time of 1 h,reaction temperature of 50℃,precipitant addition time of 5 min,CoCl₂solution concentra-tion of 0.038~0.15 mol/L,precipitant excess ratio of 1.8,and pH value of 6.When the Co content is≤2%,the cemented carbide prepared by chemical co-precipitation exhibits significantly reduced pores and defects in its microstructure compared to manually mixed samples,along with enhanced flexural strength and impact toughness.However,when the Co content reaches 14%,the pores and defects of the cemented carbide prepared by chemical co-precipitation increase significantly,and its flexural strength and impact toughness decrease significantly.Within the 6%~14%Co content range,the cemented carbides prepared by chemical co-precipitation demonstrates larger average WC grain sizes and higher overall relative densi-ties compared to manually mixed samples,while maintaining comparable hardness values.With the increase of Co content,the average grain size of WC in cemented carbides increases,and both the relative density and hardness show an overall decreasing trend.The WC-Co coarse-grained cemented carbide prepared by che-mical co-precipitation exhibits excellent mechanical properties.At 12%Co content,the cemented carbide achieves an average WC grain size of 4.2μm,a relative density of 99.6%,a Rockwell hardness of 86.3 HRA,a flexural strength of 2185 MPa and an impact toughness of 31 kJ/m².

Ti(C,N)-based steel-bonded cemented carbides were prepared by powder metallurgy method using Fe-Co-Ni as the binder phase.The effects of sintering temperature on the microstructure,phase com-position,thermodynamic properties,mechanical properties and fracture mechanism of the alloys were in-vestigated by scanning electron microscope with an attached energy-dispersive spectrometer(SEM-EDS),X-ray diffractometer(XRD),conbined with thermodynamic analysis and mechanical property testing.The results show that the main phases in the alloy are Ti(C_0.5,N_0.5)and Fe-Co-Ni solid solution.When the sin-tering temperature is lower than 1350℃,Fe₃C brittle phase still exists in the alloy.The density,trans-verse rupture strength and Vickers hardness of the alloy show a trend of increasing first and then decrea-sing with the increase of sintering temperature,while the average grain size shows a trend of decreasing first and then increasing.When the sintering temperature is 1370℃,the microstructure of the alloy is dense and the distribution of the binder phase is uniform.At the same time,the relative density,Vickers hardness and transverse rupture strength of the alloy reach the maximum values of 98.68%,1053.9 HV30 and 2280 MPa,respectively.

In this study,a self-supporting CoMoO₄@MnMoO₄ composite electrode material on a nickel foam substrate was prepared through a two-step hydrothermal method followed by annealing and calcina-tion treatments.The phase composition and microstructure of the electrode material were investigated using X-ray diffractometer(XRD)and scanning electron microscope(SEM).The electrochemical perfor-mance of the electrode material was evaluated using an electrochemical workstation.The results reveal that the CoMoO₄@MnMoO₄ electrode material possesses a dense nanosheet structure with numerous nanopar-ticles attached on the surface.The abundant nanosheet interlayer pores significantly facilitate ion transport and provide ample active sites,thereby promoting Faradaic redox reactions between the active materials and electrolyte.The electrode demonstrates an charge/discharge duration of 1500 s and achieves an exceptional specific capacitance of 726.6 C/g at a current density of 1 A/g.Furthermore,the CoMoO₄@MnMoO₄ com-posite electrode material shows significantly better rate performance than the individual CoMoO₄ and MnMoO₄ electrodes.The CoMoO₄@MnMoO₄ composite electrode material exhibits superior electrochemi-cal performance compared to its individual-components.

With the rapid development of the new energy vehicle industry,the resource and environmental challenges caused by large-scale retirement of power batteries have become increasingly severe.Developing green and efficient battery regeneration technologies has become an urgent industry demand.This study achieved electrochemical in-situ direct regeneration by introducing anti-fluorite type iron-based lithium-rich lithium compensation agent Li₅FeO₄(LFO)into retired lithium iron phosphate powders.The experimental results de-monstrate that in half-cell systems,LFO exhibits excellent lithium compensation effects on LiFePO₄ cathode materials with health states(SOH)of 90%,80%and 70%,increasing their charge spe-cific capacities by 63.2 mA·h/g,48.0 mA·h/g and 26.2 mA·h/g,respectively.Notably,the lithium compensation effect of LFO occurs exclusively during the first cycle stage,and its decomposition products exhibit high electrochemical stability,ensuring excellent cycling performance of regenerated batteries.Besides,full-cell tests further verify the lithium compensation capability of LFO.The discharge specific capacities of LFO-regenerated LiFePO₄ full batteries reach 141.0 mA·h/g(SOH 90%),140.6 mA·h/g(SOH 80%)and 141.1 mA·h/g(SOH 70%),respectively,comparable to that of the LiFePO₄ full battery with SOH of 100%.These results conclusively demonstrate the remarkable lithium compensation effect of LFO on LiFePO₄ cathode materials with varying SOH,providing a novel technical pathway for efficient recycling of retired power batteries.

近日,长沙有色冶金设计研究院有限公司(简称长沙有色院)在铜冶炼技术领域取得重大突破,其创新研发的超大型双熔池连续炼铜成套技术及装备成功攻克多项行业核心难题,显著提升了原生铜冶炼的低碳清洁生产水平,为全球铜冶炼行业节能减碳提供了全新的技术解决方案。随着铜冶炼行业原料来源日趋复杂、加工成本压力增大,以及环保要求日益严格,行业亟需规模化、高效低碳、低成本的冶炼技术。富氧侧顶吹双熔池冶炼工艺虽具备低碳、高效的优势,但曾受限于核心装备的大型化瓶颈,难以在超大型铜冶炼项目中推广应用。