Laser cladding assisted by friction stir processing for preparation of deformed crack-free Ni-Cr-Fe coating with nanostructure-猫眼课题宝

激光熔覆搅拌摩擦加工制备变形无裂纹纳米结构Ni-Cr-Fe涂层

DOI：

10.1016/j.optlastec.2017.09.025

发表时间：

2018-02

期刊：

Optics and Laser Technology

影响因子：

通讯作者：

中科院分区：

物理与天体物理2区

文献类型：

作者：

Xie Siyao;Li Ruidi;Yuan Tiechui;Chen Chao;Zhou Kechao;Song Bo;Shi Yusheng

Although laser cladding has find its widespread application in surface hardening, this technology has been significantly limited by the solidification crack, which usually initiates along grain boundary due to the brittle precipitation in grain boundary and networks formation during the laser rapid melting/solidification process. This paper proposed a novel laser cladding technology assisted by friction stir processing (FSP) to eliminate the usual metallurgical defects by the thermomechanical coupling effect of FSP with the Ni-Cr-Fe as representative coating material. By the FSP assisted laser cladding, the crack in laser cladding Ni-Cr-Fe coating was eliminated and the coarse networks of laser cladding coating was transformed into dispersed nanoparticles. Moreover, the plastic layers with thicknesses 47–140 μm can be observed, with gradient grain refinement from substrate to the top surface in which grain size reached 300 nm and laser photocoagulation net second phase crushed in the layer. In addition, cracks closed in the plastic zone. The refinement of grain resulted the hardness increased to over 400 HV, much higher than the 300 HV of the laser cladding structure. After FSP, the friction coefficient decreased from 0.6167 to 0.5645 which promoted the wear resistance.