Y_(2)O_(3)对AlCoCrFeNi高熵合金涂层组织及力学性能的影响  

Effects of Y_(2)O_(3) on microstructure and mechanical properties of AlCoCrFeNi high-entropy alloy coatings

作　　者：杨晓辉 易鸿 谢会起 李晓峰[2,3] 刘彬[3] YANG Xiao-hui;YI Hong;XIE Hui-qi;LI Xiao-feng;LIU Bin(School of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China;School of Materials Science and Engineering,North University of China,Taiyuan 030051,China;State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)

机构地区：[1]太原科技大学材料科学与工程学院,太原030024 [2]中北大学材料科学与工程学院,太原030051 [3]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《粉末冶金技术》2022年第6期549-554,563,共7页Powder Metallurgy Technology

基　　金：国家自然科学基金资助项目(52071299,51804280);山西省重点研发计划(国际科技合作)项目(201903D421075);山西省教育厅科技创新项目(2019L0556);山西省重点研发计划项目(202102050201009)。

摘　　要：利用激光熔覆技术在Q235钢基体表面分别制备出添加不同质量分数Y_(2)O_(3)的AlCoCrFeNi高熵合金涂层。采用X射线衍射仪、扫描电子显微镜、显微硬度计和摩擦磨损试验机对AlCoCrFeNi高熵合金涂层的微观组织、硬度及摩擦磨损性能进行了分析。结果表明:AlCoCrFeNi高熵合金涂层由面心立方结构(FCC)和体心立方结构(BCC)两相构成;随着Y_(2)O_(3)质量分数的提高,其体心立方结构相体积分数增加,而面心立方结构相的体积分数变化呈相反趋势。AlCoCrFeNi高熵合金涂层组织由等轴晶构成,加入Y_(2)O_(3)后,促进了熔池流动,使气孔逐渐消失,致密性提高,晶粒明显细化。添加质量分数5%Y_(2)O_(3)的涂层组织呈树枝晶状,形成弥散分布的YAl_(2)和Y_(2)O_(3)相;涂层的显微硬度可达HV 350,约为AlCoCrFeNi高熵合金涂层硬度的2倍,强化效果明显。Y_(2)O_(3)的添加有利于促进涂层中体心立方相的形成和YAl2相的析出,能有效提高高熵合金涂层的硬度及耐磨性能。AlCoCrFeNi high entropy alloy(HEA)coatings add by Y_(2)O_(3) in the different mass fraction were prepared on Q235 steel matrix by laser cladding technology in this study,and the microstructure,hardness,and wear resistance of the AlCoCrFeNi high entropy alloy coatings were analyzed by X-ray diffractometer,scanning electron microscope,microhardness tester,and friction and wear tester.The results show that,the phase structure of AlCoCrFeNi HEAs coatings is composed of face-centered cubes(FCC)phase and body-centered cubes(BCC)phase.The volume fraction of BCC phase increases with the increase of Y_(2)O_(3) mass fraction,while the FCC phase volume fraction shows the opposite trend.The microstructure of the AlCoCrFeNi high-entropy alloy coatings is composed of the equiaxed crystals,the addition of Y_(2)O_(3) promotes the melt pool flow,makes the pores disappear gradually,improves the denseness,and makes the grains become fine.The addition of 5%Y_(2)O_(3)(mass fraction)in the coatings results in the dendritic organization and the diffusely distributed YAl2 and Y_(2)O_(3) phases,and the coating microhardness reaches up to HV 350,which is about twice than that of the AlCoCrFeNi high-entropy alloy coatings,showing the obvious strengthening effect.The addition of Y_(2)O_(3) is beneficial to promote the formation of BCC phase and the precipitation of YAl2 phase in the coatings,which can effectively improve the hardness and wear resistance of the high entropy alloy coatings.

关 键 词：激光熔覆 高熵合金 双相结构 硬度 摩擦 磨损 

分 类 号：TG174.44[金属学及工艺—金属表面处理]