Effect of Al on Zn-Al Filler Metal Wettability on Pure Aluminum Surface

Abstract

Zn-Al filler metal wettability tests were performed on pure aluminum surface. The test results show the spreading area of Zn-Al filler metal gets large on pure aluminum surface gradually with the increase of Al content in Zn-Al filler metal under the match of CsF-AlF3 flux. When Al content in the Zn-Al filler metal is 15 wt.%, the spreading area of 85Zn-15Al filler metal is biggest on pure aluminum surface. Accordingly, the dendritic eutectoid structure size is smaller near the interface between the Zn-Al filler metal and the pure aluminum base metal by metallographic analysis. When Al content in the Zn-Al filler metal exceeds 15wt.%, the spreading area of filler metal begins to become small. At the same time, the eutectoid structure presents circle shape near the interface between the Zn-Al filler metal and the pure aluminum base metal.