为了研究Ti对Co基合金涂层组织及性能的影响,采用5 kW CO2激光器在低碳钢表面熔覆Co基合金涂层及Ti/Co基合金复合涂层,对比研究两种涂层的组织、显微硬度以及滑动磨损性能。结果表明,Co基合金涂层主要组成相为γ-Co,ε-Co,Cr23C6等;Ti/Co基合金复合涂层组成γ-Co,ε-Co,Cr23C6,TiC等。Co基合金涂层由发达的γ-Co枝晶和其间共晶组织所组成,Ti/Co基合金涂层典型组织为等轴固溶体以及细小的共晶组织;研究发现原位生成的TiC对熔覆层的组织有显著的改善作用,促使其由树枝晶向等轴晶转化,从而细化组织。

In order to study the effect of Ti on microstructure and properties of Co-based alloy coating,Co-based alloy and Ti/Co-based alloy composite coatings are obtained on low carbon steel surface by 5 kW CO2 laser. Microstructure,microhardness,and sliding wear resistance of the coatings are studied. The results show that Co-based alloy coating consists of γ-Co,ε-Co,Cr23C6 and Ti/Co-based alloy composite coating consists of γ-Co,ε-Co,Cr23C6,TiC and so on. The Co-based alloy coating is made up of flourishing γ-Co dendrite and eutectic structure. Equiaxed solid solution and fine eutectic structure are observed in the Ti/Co-based alloy composite coating. The influence of in-situ synthesis TiC particles on microstructure of coating is prominent. And the microstructure is refined by changing it from dendrited to equiaxed grain by TiC.