A methanesulfonic acid-bismuth methanesulfonate solution,characterized by its high stability and bismuth salt solubility,was employed as the electrolyte to systematically study bismuth membrane electrodeposition.The effects of current density,electrode distance,electrodeposition temperature,methanesulfonic acid concentration,bismuth concentration,and iron ion concentration on the bismuth electrodeposition process in the methanesulfonic acid system were investigated.The experimental results indicate a wide optimization window for bismuth electrodeposition from an iron-free methanesulfonic acid-bismuth methanesulfonate solution:current density of 150~200 A/m²,electrode distance of 5 cm,electrodeposition temperature of 40℃,methanesulfonic acid concentration of 50~80 g/L,and bismuth concentration of≥50 g/L.Under these optimized conditions,the cathode current efficiency for bismuth electrodeposition exceeds 99%,the DC power consumption per ton of bismuth is below 950 kW·h/t,and the deposited cathode bismuth metal exhibits a compact and smooth surface.In iron-containing(0~30 g/L)methanesulfonic acidbismuth methanesulfonate solution,the cathode current efficiency for bismuth electrodeposition could reach over 99%,with DC power consumption per ton of bismuth below 900 kW·h/t and cathode bismuth purity exceeding 99.90%.However,the bismuth surface is rough,which could be mitigated by methods such as adding surfactants.The methanesulfonic acid-based membrane electrodeposition process for bismuth proposed in this study is suitable for treating iron-rich bismuth-containing electrolyte.

近日,国家工业和信息化部正式发布2025年度重点产品、工艺“一条龙”应用计划方向清单。长沙有色院参与联合申报的“无氨氮钼冶金产业化技术”成功入选,标志着我国钼冶金行业向绿色化、高端化转型迈出关键一步。作为该项目的重要参与单位,长沙有色院依托有色金属冶炼工艺研发、工程转化与标准制定方面的综合优势,与牵头单位全渠钼业及各合作方协同推进该技术产业化落地与推广。在为期三年的“一条龙”应用计划中,项目团队将聚焦我国钼产业长期面临的4N高纯钼原料进口依赖度高、相关产品标准体系不健全、钼冶炼过程中氨氮污染治理难度大、无氨氮冶金技术工业化成熟度不足四大核心问题,通过系统化协作与分工攻关,力争实现四大目标,即完成关键技术知识产权布局、构建高纯钼原料产品标准体系、实现绿色低成本制造、打造全流程示范生产线,为我国钼冶金产业高质量发展提供坚实支撑。

近日,湖南省科学技术厅公布了“2025年创新联合体建设试点企业名单”,长沙有色冶金设计研究院有限公司(简称长沙有色院)成功获批湖南省深地矿产资源绿色智能开发产业创新联合体。这一重要成果标志着长沙有色院在深地矿产资源开发领域的技术实力和创新能力得到了高度认可,为推动我国深地资源开发技术的突破和产业升级奠定了坚实基础。

《稀有金属与硬质合金》创刊于1973年,是中文核心期刊,致力于稀有金属冶金与材料领域的科研创新与产业应用。本刊坚持“传播先进科技成果,引领创新,贴近科研与生产”的办刊宗旨,为科研人员及工程技术人员提供高水平的学术交流平台。为提升学术成果传播效率,缩短出版周期,本刊已于2025年7月1日起正式开通中国知网(CNKI)网络首发服务,录用定稿将优先在线发布,与印刷版具有同等学术效力。

《稀有金属与硬质合金》由长沙有色冶金设计研究院有限公司和中国有色金属学会联合主办,长沙有色冶金设计研究院有限公司负责编辑出版,为2023版北大中文核心期刊、中国科学引文数据库来源期刊,入编《中国学术期刊(光盘版)》和《中国科技期刊数据库》等数字化网络。

To enhance the surface properties of H13 steel,a WC/AlCoCrFeNi_2.1 high-entropy alloy composite coating was prepared on the surface of H13 steel using laser cladding technology.The effect of laser power on the microstructure,phase composition,hardness and friction and wear performance of the WC/AlCoCrFeNi_2.1 composite coating was studied.The results show that the laser power does not affect the phase composition of the coating.Due to the combined effect of high mixing entropy and cooling rate during laser cladding,the composite coating is composed of body-centered cubic and face-centered cubic solid solutions.The cladding layer has a typical eutectic high-entropy alloy dendritic structure.With the increase of laser power,the microstructure becomes finer first and then coarser.When the laser power is 2000 W,the WC particles melt and decompose into small-sized particles under the action of the high-energy laser beam.Due to the combined effect of fine grain strengthening and solid solution strengthening,the hardness of the composite coating reaches its maximum at this time,increased by approximately 1 times compared to the substrate.The two-phase solid solution structure of the WC/AlCoCrFeNi_2.1 composite coating refines the grooves on the friction surface,thereby improving the wear resistance of H13 steel.The friction coefficients of the coating at room temperature and 400℃under 2000 W laser power are about 1/3 of those of the substrate.The main wear mechanisms of the coating are abrasive wear and oxidative wear at room-temperature,while oxidative wear intensifies at 400℃.

Due to the insufficient understanding of the mechanism behind rare earth synergistic strengthening in cermets,this study systematically investigated the coupled effects of La₂O₃ and Y₂O₃ co-doping on the microstructure and mechanical properties of Fe/FeAl₂O₄ cermets using X-ray diffraction(XRD),field emission scanning electron microscopy(FESEM)and electron probe microanalysis(EPMA).The results indicate that La³⁺preferentially forms a solid solution in the FeAl₂O₄ lattice,while Y³⁺mainly enriches at grain boundaries to form a glass network structure.When the mass fractions of La₂O₃ and Y₂O₃ reach 0.2%and 0.5%,respectively,the average grain size of the FeAl₂O₄ phase decreases from 28.56 nm to 27.03 nm,compared with that without rare earth doping.At this point,the material exhibits optimal comprehensive properties:relative density is 99.96%,Vickers hardness is 3766 HV,and bending strength reaches 138.9 MPa,representing improvements of 4.1%,12.3%and 18.6%,respectively,compared with the sample without rare earth doping.Mechanism analysis indicates that the synergistic effect of dual rare earths promotes the in situ formation of La-Y-Si-O composite silicates,and the rod-shaped microcrystals of the La-Y-Si-O phase suppress grain coarsening through pinning effects and increase the relative density,thereby enhancing the mechanical properties.This study provides a new design strategy for rare earthmodified cermets.

Given the low room-temperature hardness and poor wear resistance of CoCrNi alloys,and that rare earth elements possess large atomic size and high chemical reactivity(even trace addition significantly enhances alloy properties),this study designed and prepared(CoCrNi)_100-xY_x(x=0,1,2,4,6,8,mass fraction,%)medium-entropy alloys via non-consumable vacuum arc melting.The influence of rare earth Y content on the microstructure and hardness of CoCrNi-based medium-entropy alloys was investigated,and their friction and wear properties and mechanisms in an ambient dry environment and a simulated seawater with 3.5%NaCl were analyzed.The results indicate that after Y addition,the morphology of CoCrNi alloy transforms from columnar grains to dendritic grains,accompanied by significant phase structural changes.On the basis of the FCC single phase,Ni-and Y-rich HCP phases(x=1,2,4,6,8)and Cr-rich BCC phases(x=4,6,8)precipitate,and the grains of the alloy are obviously refined.The hardness of the alloy increases from 154 HV without Y addition to 351 HV with 6%Y addition,due to the combined effects of secondphase strengthening and grain refinement strengthening.In an ambient dry environment,the wear mechanism of(CoCrNi)_100-xY_x transforms from oxidative/adhesive wear to abrasive/adhesive wear with increasing Y content.The(CoCrNi)₉₄Y₆ alloy demonstrates the optimal wear resistance,with an average friction coefficient as low as 0.36 and a volume wear rate of 1.42×10^-4mm³/(N·m).In a simulated seawater with 3.5%NaCl,the wear mechanism of(CoCrNi)_100-xY_x involves the synergistic effects of abrasive wear,oxidative wear and corrosive wear.The(CoCrNi)₉₄Y₆ alloy exhibits superior wear resistance,with an average friction coefficient of 0.33 and a volume wear rate of 1.65×10^-5 mm³/(N·m).The lubricating effect of the corrosive medium(3.5%NaCl solution)results in a reduction of the alloy's volume wear rate in the 3.5%NaCl simulated seawater by an order of magnitude compared to the ambient dry environment.