超音速等离子喷涂WC-12Co涂层的结合机理

Bonding mechanism of WC-12Co coatings prepared by supersonic plasma spraying on 45 steel

利用超音速等离子喷涂在经过磨抛处理的45钢基体光滑表面制备WC-12Co涂层,通过扫描电镜观察,对扁平粒子和涂层的微观结构以及结合机理等进行了探讨研究。涂层内部的结合以机械结合为主;涂层与基体的结合是以机械结合为主,还伴有部分冶金结合、物理结合和扩散。高速的未完全熔化的喷涂粒子射流在撞击基体时,硬质相WC能够嵌入到基体内部,与基体互相咬合,物理结合作用增强,从而提高了涂层与基体的结合强度。

WC-12Co coatings were prepared on polished 45 steel substrate by supersonic plasma spraying. The microstructure and the bond mechanism of flattening particles formed during the plasma spraying and coatings were observed and analyzed by SEM. Bonding of WC-12Co particles in coatings mainly belongs to mechanical bonding. Bonding between coatings and substrate mainly belongs to mechanical bonding, and partial metallurgy bonding, physical bonding and diffusion occurs. WC can be embeded in the substrate when high-speed incompletely melting particles impact onto the substrate, consequently physical bonding is strengthened and the bonding strength between coatings and substrate is improved.