激光熔覆成形Ni基合金层的研究

Research on Ni-base Alloy Coating Formed by Laser Cladding Process

采用同轴送粉式激光熔覆工艺对Ni基合金粉末进行单道单层、单道多层及多道多层熔覆成形实验。结果表明:所形成的熔覆层与基体为冶金结合;内部组织由大量的枝晶和等轴晶构成且组织均匀、致密;熔覆层硬度最高达771HV0.2,为基体材料硬度的3～4倍,耐磨性显著提高;熔覆层内部无气孔出现,局部存在少量微观裂纹。

The laser cladding process with coaxial powder feeding was used to proceed the experiments of forming Ni-based alloy coating by the way of single-track single-layer, single-track multi-layer and multi-track multi-layer methods. The experimental results indicate that the formed coating is metallurgically bonded with substrate; the interior structure is composed of lots of dendritic and equiax crystal which is uniform and densifieation; the highest hardness of cladding layer is 771HV0.2, which is the 3 -4 times more than substrate and the wear resistance is improved obviously; and the gas cavity can not found in cladding layer but micro-crack can found a little.