激光熔覆TiC增强镍基熔覆层的微观组织与耐磨性研究

Microstructure and Wear Resistance of TiC Reinforced Ni-Based Coating by Laser Cladding

选择微纳尺度TiC为增强相、镍粉为基体粉,利用激光熔覆技术制备TiC增强镍基熔覆层,考察了TiC对熔覆层微观结构和耐磨性的影响。结果表明,镍基熔覆层组织以γ-Ni和TiC为主;高TiC含量时易引起熔覆层顶部TiC偏聚;随着TiC含量增加,熔覆层的硬度逐渐增大且表层硬度升高更为明显;三体磨损实验结果表明,复合熔覆层的耐磨性随着TiC含量升高而降低,表明冲击载荷下脆性增强相不利于提升熔覆层的耐磨性。

With micro-nano TiC as reinforcing phase and nickel powder as matrix powder, a TiC reinforced Ni-based coating was fabricated by laser cladding technology, and the effect of TiC on microstructure and wear resistance of the coating was investigated. The results show that Ni-based coating has its microstructure predominately composed of γ-Ni and TiC, and a high content of TiC is prone to cause TiC segregation at the top of coating. With the increase of TiC content, coating will have its hardness increase gradually, especially have an obvious improvement in the surface hardness. A three-body wear test shows that the wear resistance of this composite coating decreases as TiC content increases, indicating that the brittle reinforcement phase is not conducive to improving wear resistance of the coating under impact load.