6063铝合金低温无铅钎焊

Low temperature lead-free soldering of 6063 aluminum alloy

添加质量分数为1%,2%,3%和4%的Bi元素和1%的Ga元素到Sn-9Zn二元合金中制备新型低温无铅钎料,对热浸镀锌的6063铝合金进行钎焊连接。采用激光共聚焦显微镜、电子扫描显微镜、X射线衍射和维氏硬度计等进行钎焊接头显微组织观察、物相分析、显微硬度分析,通过与3种传统含铅钎料钎焊接头进行对比,研究Bi和Ga元素对接头界面组织及其形成机理的影响。研究结果表明,450℃的温度下浸沾10 s时镀锌情况良好,锌液和6063铝合金相互扩散。Bi,Ga元素的添加,改善了钎料的润湿性,Sn-9Zn-x Bi-Ga/镀锌层/6063铝合金钎焊接头区存在Al0.71Zn0.29化合物颗粒;Sn87Zn9Bi3Ga钎料的钎焊接头显微硬度最高达到38.4 HV0.2,接头冶金结合最紧密,是比较适合6063铝合金低温钎焊的钎料。

A new low temperature lead-free solder was prepared by adding mass fraction 1%,2%,3%and 4%Bi with 1%Ga to Sn-9Zn binary alloy,by which the hot dip galvanized 6063 aluminum alloy was soldered.Laser confocal microscope,scanning electron microscope,X-ray diffractometer and Vickers were carried out on the soldered joint to observe microstructure,analyze phase,element distribution and microhardness,respectively.Effects of Bi and Ga element on the interface microstructure and formation mechanism of the soldered joint were studied through comparing with three kinds of traditional lead-containing soldered joints.The results showed that the galvanizing was good at the temperature of 450℃for 10 s,the zinc liquid and 6063 aluminum alloy diffused with each other.The addition of Bi and Ga elements improved the wettability of the solder.Al0.71Zn0.29 compound particles existed in the soldered joint of Sn-9Zn-x Bi-Ga/galvanized layer/6063 aluminum alloy.The maximum microhardness of Sn87Zn9Bi3Ga soldered joint was 38.4 HV0.2 and the soldered joint had the closest metallurgical bond,which was suitable for low temperature soldering of 6063 aluminum alloy.