针对铝合金激光熔注(LMI)工艺过程中对激光反射率高、表面存在氧化膜且导热率高等主要问题,开发了激光钨极氩弧(TIG)复合熔注工艺。研究了激光-TIG复合方式,送粉方式,送粉载气流,TIG保护气流,激光功率,TIG电流等工艺参数的影响。研究发现,为实现有效的熔注强化效果,应选择后送粉方式;熔注层深度随TIG电流增加单调增加,随激光功率增加熔注层深度呈先增后降。送粉载气和TIG保护气相互匹配,是影响熔注工艺的关键因素。通过工艺参数匹配和优化,成功制备了WCp/Al表面复合材料层。熔注层厚度为0.5-4.3 mm,深度可根据需要通过合理调节工艺参数来控制。

In order to overcome the difficulties of laser melt injection (LMI) on aluminium alloys,including high reflection of laser,oxide film and high heat conductivity,laser-tungsten inert gas (TIG) hybrid melt injection was exploited. The influence of process parameters,including the mode of hybrid laser-TIG,feeding powder type,the carrier gas flow,the shield gas flow of TIG,laser power and TIG current,were investigated. The results show that,in order to achieve appropriate surface enhancement effect,the powder should be fed from back side of laser beam. With the increase of TIG current,the depth of LMI layer increases monotonously. With the increase of laser power,the depth of LMI layer increases firstly and then decreases. The carrier gas flow and gas flow of TIG are the key factors which influence the LMI process,and should be matched and selected. Through optimization of process parameters,WCp/Al layer was prepared successfully on the surface of aluminium and the LMI layer with different thickness ranging from 0.5 to 4.3 mm can be achieved.