Ga2O3对CsF-RbF-AlF3钎剂在铝、钢表面润湿铺展性能的影响

本文研究了添加微量Ga2O3的CsF-RbF-AlF3钎剂和Zn-Al钎料在6063铝合金和Q235低碳钢上的润湿、铺展性能的反应规律。试验结果表明，添加极微量的Ga2O3即能够显著促进Zn-Al钎料在6063铝合金和Q235低碳钢上的润湿、铺展，其最佳添加量应控制在0.001~0.003wt.%范围。对钎剂残渣的XRD分析结果和化学反应热力学计算表明，微量Ga2O3的添加，一方面能够促进CsF-RbF-AlF3钎剂溶解、反应去除6063铝合金和Q235低碳钢表面的氧化膜；另一方面，在钎焊过程中，由于Ga2O3被还原成金属Ga，Ga元素具有“集肤效应”，富集于钎料和母材的界面，大大降低了钎料与母材间的界面张力，从而促进了钎料在母材上的润湿、铺展。

Effect of Ga2O3 on the wettability and spreadability of CsF-AlF3 flux on the aluminum and steel

Effect of trace amount of Ga2O3 addition on the changes of the wettability and spreadability of CsF-RbF-AlF3 flux and Zn-Al filler metal were investigated on 6063 aluminum alloy and Q235 low-carbon steel. The experimental results indicated that trace amount of Ga2O3 addition in the flux could obviously promote the Zn-Al filler metal to wet and spread on the surface of 6063 aluminum alloy and Q235 low-carbon steel, in which the optimum range of Ga2O3 was 0.001~0.003wt.%. According to the XRD results of the flux residua and the thermodynamic calculation, it could be concluded that the trace amount of Ga2O3 addition could enhance the solubility and reactivity of CsF-RbF-AlF3 flux to the surface oxides on 6063 aluminum alloy and Q235 low-carbon steel. On the other hand, Ga2O3 could also be reduced to Ga. Because of its skin effect, Ga could enrich on the interface of filler metal and base metal and effectively decreased its interfacial tension, which could improve the wettability and spreadability of the filler metal.