6061铝合金中温钎焊接头组织与性能

采用自行研制的AlZnSi中温钎料,对6061铝合金进行了火焰钎焊试验,并对其接头组织及性能进行了研究.结果表明,改进的无腐蚀KCsAlF4钎剂能很好的去除铝合金表面的氧化膜,促进钎料在铝材表面铺展.Si元素在钎料中以片状或者针状相存在,在钎缝中也呈现这两种状态,并且当Si元素含量较高时,针状相明显.钎料中Si元素含量及Al元素含量较高时,钎缝中形成的针状相受力时会产生应力集中;而较高的Si元素含量及Al元素含量同时也有利于钎缝中晶粒细化.6061铝合金火焰钎焊对接接头气密性及强度均满足要求,并且两种钎料的焊接接头断口都呈现出明显的沿晶断裂特征.

Microstructure and mechanical properties of 6061 Al joints brazed with a low-melting point filler

Two self-designed AlZnSi alloys were utilized to braze 6061Al alloy,the microstructures and mechanical properties of the joints were also studied.The results showed that the improved non-corrosive flux KCsAlF4 could effectively remove the oxide film on 6061 Al surface.Element Si exists as the plate type and needle type in both the filler metal and brazing seams.The needle type phase is much more obvious when the Si content is high,and the brittle phase could induce the stress concentration.However,the higher content of Si and Al is helpful to refine the grain size in the brazing seam.Both of the strength and gas tightness properties of 6061Al brazed joints are satisfactory,and the fracture shows intergranular fracture characterizes.