改善激光熔覆镍基合金和陶瓷硬质相复合涂层性能的研究

Study of Improvement of Properties of Laser Cladding Ni Superalloy and WC Composite Layers

激光熔覆镍基合金和陶瓷硬质相（WC）复合涂层过程中存在的问题是容易形成缺陷和开裂。通过调整WC的比例和分布，合理的工艺参数，增设韧性良好的过渡层，并加入微量混合稀土氧化物，对发生马氏体相变硬化的热影响区进行激光回火处理等，以获得无裂纹缺陷，金相组织均匀，并具有硬度平滑过渡的优质熔覆层。

In order to reduce the cracks and porosity, which always appear in the laser cladding composites of Ni superalloy and WC hard-phase, some methods were introduced in this paper: 1. uniform distribution of WC; 2. reasonable processing parametersi 3.application of a tough transition layer; 4. application of 0. 1 wt-% mixed rare earth cerium; 5.laser tempering the heat-affected zone in order to obtain a tough structure. The experimental results indicate that the laser cladding coating has a uniform microscopicstructure and is free of cracks. Due to the transition layer, the micro-hardness curve of cladding is smmother than that without the soft layer.