激光熔覆制备WCp/Ni-Si-Ti复合涂层

在Ni基高温合金表面预置3种不同WC含量的Ni78Si13Ti9(at%)粉末,采用激光熔覆制备了WC和原位自生TiC复相陶瓷增强Ni3(Si,Ti)基复合涂层.利用扫描电镜、能谱分析仪和X射线衍射仪对熔覆层组织进行分析,并测量了其显微硬度.结果表明,熔覆层与基体呈冶金结合,熔覆层组织主要由Ni(Si)固溶体、Ni3(Si,Ti)金属间化合物和WC-TiC复相陶瓷组成.随WC添加量增加,涂层中复相陶瓷含量增多;孔隙率增大;碳化物形态演变历程为不规则状、花瓣状以及不规则状和花瓣状共存.

Laser Clad WCp/Ni-Si-Ti Composite Coatings

Using laser cladding technique,Ni3(Si,Ti) matrix composite coatings reinforced by WC and in-situ synthesis TiC multi-ceramics were fabricated by preplacing Ni78Si13Ti9(at%) powders containing three different WC contents on the nickel-matrix superalloy substrate.By means of SEM,EDS and XRD,microstructures of the coatings were investigated,and micro-hardness were measured.The results showed that excellent metallurgical bonding between the coatings and the substrates was obtained.Phases of the coatings are mainly composed of gamma Ni(Si) solid solution,Ni3(Si,Ti),WC-TiC multiceramics.With increasing WC percentage,content of carbides formed in the coatings increases,but porosity is also enhanced.The main morphologies of ceramics evolve from irregular polygonal shape to petal like shape,then irregular polygonal shape coexisting with petal like shape.