The effects of a third elements, i.e., Ag, Al, and Ga, on melting temperature, microstructures, and mechanical properties of the Sn-9Zn lead-free solders were investigated. The results indicate that Ga is uniformly distributed in the Sn-matrix, Al is detected in the grain boundaries and Zn-rich phases, and Ag combines with Zn to form an Ag-Zn compound. The adding of 0.5 wt% Ag, results in decreasing the UTS and ductility. By the addition of Al the UTS and elongation of the Sn-9Zn-0.45Al alloy can be decreased due to the Al element precipitated in the grain boundaries. The Sn-9Zn-0.5Ga alloys have very good UTS and elongation, which are better than both those of the Sn-9Zn-0.5Ag and Sn-9Zn-0.45Al alloys.
關聯:
Journal of Alloys and Compounds, Vol.416, pp.98-105
