(1. 哈尔滨工业大学 先进焊接与连接国家重点实验室，哈尔滨 150001；
2. 哈尔滨工业大学 金属精密热加工国家重点实验室，哈尔滨 150001)
摘 要: 采用激光填丝钎焊方法进行1.5 mm厚65%(体积分数)Sip/4032Al复合材料对接接头的连接，研究不同工艺参数下的钎料润湿铺展行为和焊缝成形特性，以及焊缝中共晶硅的形态变化规律。结果表明：接头开V型坡口非常有利于焊缝的背面成形；光斑直径为20 mm、激光功率高于1 500 W时焊缝成形容易控制；与激光熔焊相比，激光钎焊方法更适合于连接高比分Sip/4032Al复合材料。焊接热输入对Si元素的溶解、扩散行为影响很大，因此，不同激光功率下，焊缝中硅元素可以板状、多角状、瓣状初生硅、板条状共晶硅等多种形态出现。焊缝中心由于冷却速度较慢，还形成了共晶团组织，共晶团内部为均匀分布的短棒状共晶硅。
关键字: Sip/Al复合材料；激光钎焊；硅结晶行为
（1. State Key Laboratory of Advanced Welding and Joining,
Harbin Institute of Technology, Harbin 150001, China;
2. National Key Laboratory for Precision Hot Processing of Metals,
Harbin Institute of Technology, Harbin 150001, China）
Abstract:Laser brazing method was used to join 1.5 mm thick 65% (volum fraction) Sip/4032Al composite butt joints. The wetting and spreading behavior of brazing filler metal, characteristics of weld shaping, and morphologies of eutectic silicon with different process parameters were investigated. The results show that the V-groove is favorable to the weld back shaping, the weld shaping is easy to be controlled when the spot diameter is up to 20 mm and the laser power is higher than 1 500 W. Compared with laser fusion welding, the laser brazing method is more suitable for joining high fraction Sip/4032Al composite. Weld heat input has great influence on Si dissolution and diffusion, so various silicon morphologies are found in the weld under different laser powers, including strip, polygonal，petal primary silicon and lath-shaped eutectic silicon. The eutectic cells are formed at the centre of weld because of the lower cool rate.
Key words: Sip/Al composite; laser brazing; silicon crystallization behavior
