激光熔覆在AlN陶瓷表面制备铜基金属覆层缺陷分析及控制

通过脉冲式YAG激光器在AlN陶瓷表面制备铜基金属覆层，分析熔覆层的缺陷，并研究如何能控制熔覆层缺陷的发生，熔覆试样的缺陷主要表现为陶瓷基板炸裂、熔覆层成形不完整、熔覆层微观裂纹和气孔.结果表明，通过调节激光熔覆的热输入可以保证陶瓷基板的完整性并且熔覆层成形良好；通过焊前预热和焊后缓冷的工艺可以降低熔覆层微观裂纹和气孔的形成几率.通过优化激光熔覆工艺参数和工艺方法，可以形成良好的熔覆层，并且AlN陶瓷基板和铜基金属覆层之间形成过渡层，形成良好的冶金结合.

Analysis and control of defects in preparing copper-based metal coatings on AlN ceramic surface by laser cladding

Copper-based metal coatings were prepared on the surface of AlN ceramics by pulsed YAG lasers. The defects of the cladding layers were analyzed. It was also studied how to control the occurrence of defects in the cladding layers. The defects of the cladding samples were mainly the cracking of the ceramic substrate. Cladding formation incomplete, micro-cracks cracks and pores. The results show that by adjusting the heat input of the laser cladding, the integrity of the ceramic substrate can be ensured and the cladding layer can be well formed. The pre-heating before welding and slow cooling after welding can reduce the micro cracks and the formation probability of the pores. By optimizing the laser cladding process parameters and process methods, a good cladding layer can be formed, and a transition layer is formed between the AlN ceramic substrate and the copper-based metal cladding to form a good metallurgical bond.