无镀镍铜/铝低温钎焊工艺优化

Process Optimization of Low Temperature Brazing Technology of Copper and Aluminum with No Nickel Plating

先在铝板表面用刮擦钎焊法搭配M51钎料进行涂层处理,再将铜板与铝板使用焊锡进行钎焊连接。研究了涂层温度对涂层金属与铝基体结合效果的影响,确定了最佳的涂层温度;采用正交试验研究了铜/铝板的分层钎焊,将焊接件的剪切强度作为试验指标,以极差法为分析手段,确定了焊接参数的影响程度以及最佳焊接参数,同时对最优焊接参数下焊接件的微观形貌及界面元素扩散行为进行了研究。结果表明:当涂层温度为350℃时,涂层与铝基体结合效果最佳;焊接电流对铝铜焊接接头的拉伸力影响最显著,当焊接电流为100 A、焊接温度为210℃,焊接压力为0.3 kN时,铜铝板实现了有效连接,剪切强度为24.6 MPa;铝铜接头结合面平整,并且界面处存在一定厚度的扩散层,铝铜焊接接头的连接主要依靠元素扩散实现。

The surface of aluminium sheet was coated with M51 solder by scratch brazing, and then the copper sheet and aluminium sheet were brazed with soldering tin. The effect of coating temperature on the bonding effect of coating metal with aluminum substrate was studied, and the optimum coating temperature was determined. The layered brazing of copper/aluminum plate was studied by orthogonal test, and the shear strength of the welded part was taken as the test index.The influence degree of welding parameters and the optimum welding parameters were determined by means of range method.At the same time, the micro-morphology and interface element diffusion behavior of the welded parts under the optimal welding parameters were studied. The results show that when the coating temperature is 350 ℃, the bonding effect between the coating and the aluminum substrate is the best. The welding current has the most significant effect on the tensile force of the Al-Cu welded joint. When the welding current is 100 A, the welding temperature is 210 ℃, the welding pressure is 0.3 kN,the effective connection is realized, and the shear strength is 24.6 MPa. The bonding surface of Al-Cu joint is flat and there is a certain thickness of diffusion layer at the interface. The connection of Al-Cu welded joint is mainly realized by element diffusion.