Effects of Ti on the Brazability of Zn-22Al-xTi Filler Metals as Well as Properties of Cu/Al Brazing Joints

设计并采用Zn-Al-Ti系列钎料对Cu和Al异种金属实施了钎焊，并对Zn-22Al-xTi/Cu界面处的相组成和金属间化合物形貌进行了分析。结果表明：在Zn-22Al中添加0.01%至0.05%的Ti可以显著细化钎料组织，而且Zn-22Al-0.03Ti在Cu基板上的铺展面积比Zn-22Al高出60.4%，但Ti的添加会提高Zn-22Al钎料的熔点和熔化区间。另外，在钎料中添加微量的Ti可以优化Cu/Al接头中Cu侧界面化合物的组织并减小其厚度。相比Zn-22Al钎料，Zn-22Al-0.03Ti钎焊所得Cu/Al接头强度要高出13.4%，而且接头断裂位置由化合物层转移至钎料内部。X射线衍射结果显示，钎焊过程中有CuAl2，Cu9Al4，CuZn 3种化合物产生于钎料与Cu基板界面处

Effects of Ti on the Brazability of Zn-22Al-xTi Filler Metals as Well as Properties of Cu/Al Brazing Joints

Noval Zn-Al-Ti filler metals have been designed and used to braze Cu and Al dissimilar metals. The phase constitutions and morphologies of intermetallic compounds at the Zn-22Al-xTi/Cu interfaces were studied in this paper. The results indicate that, with Ti addition from 0.01 wt% to 0.05 wt%, the microstructure of the Zn-22Al alloy are refined significantly. The spreading area of Zn-22Al-0.03Ti on Cu substrates increases by 60.4% compared with that of ZA. However, the melting range and melting point of the Zn-22Al-xTi alloys also increase with the addition of Ti. In particular, the addition of trace Ti into the Zn-22Al filler metal can refine the microstructures and decrease the thickness of the intermetallic compounds layer produced in the Cu/Al brazing. The shear strength of Cu/Al joint brazed with Zn-22Al-0.03Ti is 13.4% higher than that of the Zn-22Al filler metal, and the fracture position changes from the interface layer to the matrix of the filler metals. The X-ray diffraction result indicates that the CuAl2, CuZn, and Cu9Al4 phases are produced at the filler metal/Cu substrate interface