中文摘要：

采用5 k W横流CO2激光器在45钢基体上熔覆自制的镍基金属陶瓷涂层,对熔覆涂层的成型性、物相组成、组织形貌、显微硬度及摩擦磨损性能进行研究。结果表明：激光熔覆层成型良好,组织细密均匀,主要为Ni-Fe固溶体中分布Fe2B,WC,M7C3型及M23C6型碳化物。熔覆层靠近基材的组织为发达树枝晶,中上部为基体组织上分布着大量长条状及少量零散分布的菊花状物质,但上部晶粒分布的方向性减弱,晶粒更加细小致密。熔覆层搭接时,搭接界面存在着生长方向多与结合面相垂直的树枝晶组织过渡区。熔覆层的显微硬度约600 HV0.2,沿搭接方向没有明显波动,其摩擦系数、磨损失重及磨损程度较基体45钢明显降低,耐磨性显著提高。

英文摘要：

Laser cladding of self-made Ni-based ceramic layer was prepared on a 45 steel surface by transverse flow CO2 laser. The morphology,phase composition,microstructure,micro-hardness and wear properties of the layer were investigated.Results show that the formability of cladding layer is excellent. There are Ni-Fe solid-solution,Fe2 B,WC,M7C3 and M23C6carbides in the coating. Dentrite is highly developed on the bottom of the cladding layer. In the microstructures of the central and top zone there are plenty of grains with long strip shape,and a few chrysanthemum-like grains are distributed on the substrate,but the grains of the top zone are finer and denser. There is an interface transition region,where coarser dendrites grow in the direction vertical to the bonding interface. The micro-hardness of cladding layer is about 600 HV0. 2,and it has no significant fluctuations along the horizontal direction. The friction coefficient,the wear weight loss and the wear degree are significantly reduced compared with 45 steel,and the anti-wear characteristic is remarkably improved.