等离子熔覆CoCrFeNiMo高熵合金相结构及显微组织研究  

Phase Structure and Microstructure of CoCrFeNiMo High-entropy Alloy Prepared by Plasma Cladding

作　　者：王虎 王兴阳 彭云[2] 赵琳[2] 王智慧[4] 贺定勇[4] WANG Hu;WANG Xing-yang;PENG Yun;ZHAO Lin;WANG Zhi-hui;HE Ding-yong(College of Materials Engineering,North China Institute of Aerospace Engineering,Hebei Langfang 065000,China;State Key Laboratory of Advanced Steel Processes and Products,Central Iron&Steel Research Institute,Beijing 100081,China;Panasonic Welding Systems(Tangshan)Co.,Ltd.,Hebei Tangshan 063020,China;Faculty of Materials and Manufacturing,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北华航天工业学院材料工程学院,河北廊坊065000 [2]钢铁研究总院先进钢铁流程及材料国家重点实验室,北京100081 [3]唐山松下产业机器有限公司,河北唐山063020 [4]北京工业大学材料与制造学部,北京100124

出　　处：《表面技术》2022年第12期116-121,130,共7页Surface Technology

基　　金：河北省重点研发计划(18211041);河北省高等学校科学技术研究项目(QN2020256);北华航天工业学院青年基金(KY202103);河北省大学生创新创业训练计划(CX2023093)。

摘　　要：目的在普通低碳钢表面制备含难熔金属Mo的CoCrFeNiMo高熵合金熔覆层,研究熔覆层的组织结构及性能。方法将Co、Cr、Fe、Ni、Mo金属单质粉末按等摩尔比进行配制并混合均匀,利用等离子熔覆法在Q235钢表面制备CoCrFeNiMo高熵合金熔覆层,采用X射线荧光光谱仪(XRF)、X射线衍射仪(XRD)、金相显微镜(OM)、扫描电子显微镜(SEM)、显微硬度计对熔覆层的合金成分、相结构、显微组织和硬度进行研究。结果在等离子熔覆过程中存在元素烧损现象,熔覆层的实际成分为Co_(1.17)Cr_(0.92)Ni_(1.06)Fe_(0.92)Mo_(0.92)(摩尔分数);熔覆层与基材形成了良好的冶金结合,熔覆层主要由FCC相组成,同时夹杂少量富Mo、Cr的σ相;熔覆层显微组织为树枝晶,枝晶内为固溶多种元素的FCC相,枝晶间是由FCC相和富Mo、Cr的σ相组成的共晶组织。高熵合金物相形成规律较为复杂,其相结构不能仅由热力学参数来预判,仍需要实验结果的验证。由于Mo元素的固溶强化及σ相的沉淀强化,使得熔覆层的硬度明显提高,表面硬度约为485HV。结论利用等离子熔覆法,在Q235钢表面成功制备了含难熔金属Mo的CoCrFeNiMo高熵合金熔覆层,显著提高了CoCrFeNi高熵合金的硬度。The research is intended to prepare CoCrFeNiMo high-entropy alloy containing refractory metal Mo on the low carbon steel,and do some researches about the microstructure and mechanical properties of this cladding layer,and then provide theoretical reference and the experimental example for the subsequent research of high melting point high-entropy alloy in surface engineering.Co,Cr,Fe,Ni,Mo metal powders were mixed evenly according to the equal molar ratio.And then the CoCrFeNiMo high-entropy alloy cladding layer was manufactured on Q235 steel by plasma cladding.The alloy components,crystal structure,microstructure and microhardness of this cladding layer were investigated by XRF,XRD,OM,SEM and microhardness tester.The results showed that due to the element burning phenomenon in the process of plasma cladding,the actual composition of the cladding layer was Co_(1.17)Cr_(0.92)Ni_(1.06)Fe_(0.92)Mo_(0.92).The cladding layer formed a good metallurgical bond with the substrate.The cladding layer was mainly composed of FCC phase with a small amount ofσphase.The microstructure was dendrite structure.Furthermore,the dendrite was FCC phase with a variety of elements,and the interdendrite was eutectic structure composed of FCC phase andσphase rich in Mo and Cr.In addition,the phase formation law of high-entropy alloy was very complex and its phase structure could not be predicted only by thermodynamic parameters,but still needed to be verified by experimental results.Due to the solid solution strengthening of Mo element and the precipitation strengthening ofσphase,the hardness of the cladding layer was obviously improved,and the hardness of the surface was about 485HV.Therefore,the CoCrFeNiMo high-entropy alloy cladding layer is successfully prepared on Q235 steel by plasma cladding.The hardness of CoCrFeNi high-entropy alloy is improved by adding Mo.

关 键 词：等离子熔覆 高熵合金 Mo元素 相结构 显微组织 显微硬度 

分 类 号：TG174.4[金属学及工艺—金属表面处理]