激光重熔对电火花沉积Ni基涂层组织及耐磨性能的影响  

Effects of Laser Remelting on Microstructure and Wear Properties of Ni-Based Coating Prepared by Electrospark Deposition

作　　者：高玉新[1,2] 王均波 GAO Yu-xin;WANG Jun-bo(Rizhao Polytechnic,Rizhao 276826,China;Zhejiang Provincial Key Laboratory of Measurement and Deep Processing Technology,Taizhou 318000,China)

机构地区：[1]日照职业技术学院,山东日照276826 [2]浙江省工量刃具检测与深加工技术研究重点实验室,浙江台州318000

出　　处：《材料保护》2021年第1期112-115,120,共5页Materials Protection

基　　金：台州市科技计划项目(1702gy06);日照职业技术学院校本研究重点课题(2019Z09)资助。

摘　　要：采用激光重熔工艺对电火花沉积Ni基涂层进行重熔处理,以减少或消除电火花沉积Ni基涂层中的裂纹、孔隙和夹杂等缺陷。利用SEM、XRD和摩擦磨损试验机研究了Ni基涂层在重熔前后的组织结构及力学特性的变化。结果表明:经过激光重熔处理后,电火花沉积Ni基涂层的组织由重熔前的枝晶组织细化为均匀分布的超细晶粒,重熔涂层上部出现纳米级晶粒,并且析出Cr2B、Cr7C3和FeNi3超细硬质相。激光重熔使电火花沉积涂层中的裂纹、孔隙及夹杂等缺陷明显减少。晶粒细化作用致使涂层硬度提高,其耐磨性能得到改善;涂层的磨损机理由重熔前的疲劳磨损变为重熔后的磨粒磨损。Ni-based coating by electrospark deposition was remelted by pulse laser equipment in order to remove cracks,holes and inclusion in the coating. The changes in microstructure and mechanical properties of the coating were investigated by SEM,XRD and frictional testing machine. Results showed that the dendritic structure of the coating was changed into evenly distributed superfine grains after laser remelting,and the grains in the upper of the coating reached nanometer size. Meanwhile,the precipitation of hard phases,such as Cr B,Cr7 C3 and Fe Ni3,were observed. Laser remelting reduced the cracks,pores and inclusions in the coating. The effect of grain refinement improved the hardness and wear resistance of the coating. The wear mechanism of Ni-based coating was changed from fatigue wear to abrasive wear after laser remelting treatment.

关 键 词：激光重熔 电火花沉积 NI基涂层 微观组织 耐磨性能 

分 类 号：TG406[金属学及工艺—焊接]