采用扫描电镜、材料试验机等研究了表面化学镀镍后增强相体积分数为55%的SiCp/6063Al复合材料与可伐合金真空钎焊接头的显微组织、剪切断口形貌以及钎焊保温时间对接头组织和性能的影响。结果表明: 表面镀镍后的SiCp/6063Al复合材料能够实现与可伐合金的真空钎焊, 在550 ℃下保温20 min能得到剪切强度为100 MPa的接头, 其断裂性质为脆性断裂;钎料中的钛元素能够与复合材料中的SiC颗粒发生化学反应, 达到钎料与基体的冶金结合;焊缝组织致密, 钎料对可伐合金和镀镍复合材料的润湿性都良好。

The microstructure and shearing fracture morphology of the vacuum brazed joint between the SiCp/6063Al composites with 55vol.% of SiC particles after nickel plating on their surface and Kovar alloys were studied by means of scanning electron microscopy and shearing testing. The effects of soaking time on the microstructure and property of the joint were also investigated. The results show that the SiCp/6063Al composites after surface nickel plating could be jointed together with Kovar alloys by means of vacuum brazing technique. The joint with shear strength of 100 MPa was achieved at the brazing temperature of 550 ℃ and soaking time of 20 min, which showed typical brittle fracture. The element Ti from the brazing filler metal reacted with SiC particles in the SiCp/6063Al composites, resulting in a metallurgical bonding between the filler metal and base material. The microstructure of weld metal was quite compact since the brazing filler metal can wet the Kovar alloy and SiCp/6063Al composites after nickel plating very well.