碳化硅颗粒增强铝基复合材料SiC(P)/LD2的钎焊机理

Brazing of Silicon Carbide Particle Reiforced LD2 Aluminum Composites

就ＳｉＣ颗粒增强铝基复合材料ＳｉＣ（Ｐ）／ＬＤ２的钎焊过程及钎焊机理进行探索研究，在惰性气体保护的钎焊条件下获得了良好的焊接质量，焊后对钎缝作剪切强度试验及金相分析，发现钎缝被分成四个截然不同的组织区域。借助于扫描电镜及能谱射线成分分析，对钎料与母材的润湿及相互扩散机理进行了全面深入的分析研究，对钎缝四区的形成过程，不同钎焊条件下的钎缝强度及断裂特征作出了合理的分析解释。

The brazing of LD2 aluminum alloy reinforced with 10 volume percent SIC particles was studied in this paper. Each joint was made in an inert gas atmosphere furnace with a pressure of 5kPa on the faying surfaces. Mechanical shear test and metallography were performed on each joint, which showed that the bonded joint can be classified tnto four distinct areas:1 Al-Si eutectic area at the center of the joint; 2. the α-Al solid solution area next to the Al-Si eutectic area resulted from the decrease of silicon concentration in the filler metal due to the interdiffusing with base meatl; 3.SiC particles concentrated area next to the α-Al solid solution area;4. α-Al solid solution area deficient in SiC particles near the base metal. EDX unit which accompanies the SEM was also used to study the wetting and dissolution characteristics of the joining systems. Connecting it with the join structure, we give a reasonable explain to the forming of four distinct areas and the different strength and fracture feature of the joints with different temperature and time.