送粉激光熔覆WC陶瓷层的高温组织与性能

The high temperature microstructure and property of WC ceramic layer produced by powder feeding laser cladding

实验研究了Co基自熔合金、Ni基自熔合金+WC、Co基自熔合金+WC激光熔覆层在不同温度下的显微组织和各种化合物的硬度,结果表明三种材料在相同激光熔覆工艺参数下获得的熔覆层的高温显微组织、性能存在很大的差异,Ni基自熔合金+WC在700℃时硬度开始显著降低且显微组织发生很大变化,而Co基自熔合金和Co基自熔合金+WC在700℃时才开始发生变化且变化幅度较小。同时证明WC在加热过程中硬度没有显著降低。实验结果对获得具有抗高温粘着磨损的激光熔覆层有重要的理论和实际意义。

Three kinds of coating were prepared by powder feeding type laser cladding using powders consist of self-smelting Co-base alloy with without WC, and self- smelting Ni-base alloy plus WC. Microstructure and hardness at different temperatures of the samples were studied experimentally. The results show that the three samples differ significantly in structure and property under the same laser processing parameters. For the Ni-type alloy, its hardness decreases markedly at 700℃ with an obvious structural changes while for the Co-type alloys, the occurrence of changes starts only at 700℃ .and the extent of the changes with temperatures are smaller. Also, it has been proved that no prodigious change in the hardness of WC can be observed with the rise of temperature. These conclusions provide important reference for the designing of ami- adhesive wear parts.