用Co基新合金粉为梯度涂层原材料, 在结晶器用Cu-Cr合金表面利用激光诱导原位制备陶瓷相增强Co基合金梯度涂层。对实验制备样品涂层的组织结构与性能进行了研究。结果表明, 激光制备Co基梯度涂层的工艺参数为：激光平均功率50 W, 频率15 Hz, 脉宽3 ms, 扫描速度4.0 mm/s, 搭接率20%～25%。实验制备出了3层具有不同成分和结构的梯度涂层, 梯度涂层的主要组织是α-CoCr2(Ni, O)4合金相, 而Fe-Ni, Cu-Ni以固溶相的形式存在其中, 梯度涂层的各个分层中原位生成的碳化物陶瓷颗粒的数量、密度都呈现由内层到外层逐渐增大的趋势。梯度涂层的平均显微硬度由铜合金基体的94 HV呈梯度递增加到了最外层的432 HV, 摩擦实验表明梯度涂层的最少磨耗量为0.008 g, 表明激光原位制备的梯度涂层具有良好的耐磨性能。

The newly developed Co-based alloy powders is taken to prepare a ceramic particles, with reinforcing Co-based alloy gradient coating on surface of Cu-Cr alloy for crystallizer through pulse laser induced reaction in-situ. The microstructure and property of the gradient coating is studied experimentally by means of analysis techniques. The result shows that large-area Co-based gradient coating has synthesized with the laser processing parameters: average power of 50 W, frequency of 15 Hz, pulse width of 3 ms, scanning speed of 4.0 mm/min, and overlapping rate of 20%-25%. There are three different elements and structure layers consisting a gradient coating on the surface of Cu-Cr alloy. The main structure of the coating is α-CoCr2(Ni, O)4 alloy phase, with Fe-Ni, Cu-Ni as the solid solution phase enwrapped in it. The number and density of carbide ceramic particles synthesized in-situ increases gradually from inside layer to outside layer in the gradient coating. Hardness of the Co alloy gradient coating increases obviously, from 94 HV (substrate) to 432 HV (the out layer of coating), and the least wear lost is 0.008 g. It can prove that the wear resistant of the Co alloy gradient coating prepared by laser induced reaction in-situ is excellent.