火焰喷焊和等离子堆焊制备Ni60及Ni60-WC涂层的组织与性能

Microstructure and Properties of Ni60 and Ni60-WC Coatings by Flame Spraying and Plasma Arc Surfacing

采用火焰喷焊与等离子堆焊工艺分别制备了Ni60与Ni60-WC涂层,对比研究了两种涂层的显微组织、物相组成、硬度和耐磨性能。结果表明:Ni60与Ni60-WC喷焊层比相应堆焊层的内部缺陷多、孔隙率高;喷焊层硬度曲线波动大,堆焊层硬度分布均匀;喷焊层磨损表面粗糙,划痕较多,而堆焊层磨损表面平滑;WC颗粒的添加提高了喷焊层与堆焊层的硬度和耐磨性;火焰喷焊工艺下,WC颗粒的添加使得涂层孔隙率增大,WC颗粒发生一定的脱碳,而等离子堆焊工艺下WC颗粒的添加对涂层孔隙率影响不大,WC颗粒能较完整地保存在涂层内。

The Ni60 and Ni60-WC coatings were prepared by flame spray welding and plasma arc surfacing,respectively.The microstructure,phase composition,hardness and wear resistance of the two coatings were studied and compared.The results show that the flame spray welded Ni60 and Ni60-WC coatings had more internal defects and a higher porosity than the plasma arc surfaced coatings.The hardness curves of the spray-welded coatings fluctuated greatly while the hardness of the surfaced coatings distributed evenly.The wear surface of the spraywelded coating was rough and had relatively more scratches,while that of the surfaced coating was smooth.The addition of WC particles improved the hardness and wear resistance of the spray-welded and surfaced coatings.By the flame spray welding,the addition of WC particles increased the porosities of the coatings and resulted in a certain decarbonization of WC particles,while the WC particles had little influence on the porosities of the coatings by the plasma arc surfacing and the WC particles were relatively complete in the coatings.