铸造镍基K3合金的激光熔覆开裂及工艺研究

The Study on the Laser Cladding Process and Cracking of Cast Ni-Based Superalloy K3

研究了铸造镍基Ｋ３合金的激光熔覆过程，分析了原始组织及激光熔覆工艺参数对熔覆裂纹形成的影响及作用；探讨了使用激光熔覆技术对损伤的Ｋ３合金叶片进行修复的可能性。研究结果表明，Ｋ３合金中沿晶界分布的低熔点共晶及碳化物是引起激光熔覆开裂的主要因素，采用较高的功率密度和较快的扫描速度进行激光熔覆，可减少热影响区范围，明显地抑制熔覆裂纹的产生。

Laser cladding process of cast Ni-based superalloy K3 was studied in this paper. Action and influence of original structure of K3 and laser process parameters on the cladding cracks were ana lyzed.The possibility of repairing of damaged blade by the method of laser cladding was discussed.The results show that the eutectic phase with low melting point and carbide existed in the grain boundary of K3 are the main factors causing the cladding cracks.Higher laser power density and scanning speed could ob versely reduce the cracking possibility.