B对FeCoCrNiSiB_x高熵合金激光熔覆层组织和硬度的影响  

Effect of B on microstructure and hardness of FeCoCrNiSiBx high entropy alloy laser clad coating

作　　者：赵龙志 喻世豪 赵明娟 唐延川 焦海涛 李劲 宋立军 Zhao Longzhi;Yu Shihao;Zhao Mingjuan;Tang Yanchuan;Jiao Haitao;Li Jin;Song Lijun(School of Materials Science and Engineering,East China Jiaotong University,Nanchang Jiangxi 330013,China;Tongda Industry and Trade Co.,Ltd.,Nanchang Railway Administration,Nanchang Jiangxi 330013 China;College of Mechanical and Vehicle Engineering,Hunan University,Changsha Hunan 410082,China)

机构地区：[1]华东交通大学材料科学与工程学院,江西南昌330013 [2]南昌铁路局通达工贸有限责任公司,江西南昌330013 [3]湖南大学机械与运载工程学院,湖南长沙410082

出　　处：《金属热处理》2020年第10期187-190,共4页Heat Treatment of Metals

基　　金：国家自然科学基金(51761012,51965022);江西省科技厅科技项目(20153BCB23005,20192BAB206028);华东交通大学科研启动基金(2003419036)。

摘　　要：采用激光熔覆制备了FeCoCrNiSiB_x高熵合金熔覆层,利用光学显微镜、扫描电镜、X射线衍射仪和显微硬度计研究微量硼元素(摩尔比x=0、0.02、0.04、0.06、0.08)对FeCoCrNiSiB_x高熵合金熔覆层组织和硬度的影响。结果表明:无B高熵合金涂层组织主要为胞状晶。B的添加会促进枝晶的生成,逐渐形成鱼骨状树枝晶,但过量的B会破坏枝晶完整性,形成蠕虫状晶。此外,高熵合金熔覆层组织为FCC和BCC双相结构,B元素的添加会形成大量0.1~2.6μm的Cr_2B第二相,有助于提高熔覆层硬度,其中x=0.06时激光熔覆层的硬度最高,约为537 HV0.2。FeCoCrNiSiBx high-entropy alloy coating was prepared by laser cladding.The influence of trace boron element(molar ratio x=0,0.02,0.04,0.06,0.08)on the structure and hardness of FeCoCrNiSiBx high-entropy alloy coating was study by using optical microscope,scanning electron microscopy,X-ray diffractometer and microhardness tester.The results indicate that the microstructure of FeCoCrNiSi high-entropy alloy coating can be mainly characterized by cellular.The addition of B promoted the formation of dendrites,resulting in fish-bone dendrites.However,the excessive content of B destroies the integrity of dendrites,leading to worm-like dendrite.In addition,the microstructure of the coating is composed of FCC and BCC phases.The addition of B element promotes the precipitation of Cr2B particles of size 0.1-2.6μm,which contributes the improvement of hardness of the clad coating.When the molar ratio of B is 0.06,the value of microhardness of the clad coating is highest as about 537 HV0.2.

关 键 词：高熵合金熔覆层 激光熔覆 B元素 微观组织 硬度 

分 类 号：TG174[金属学及工艺—金属表面处理]