Using microwave assisted powder metallurgy route and nano-size reinforcements to develop high strength lead-free solder composites

Abstract

In the present study, Sn-0.7Cu and Sn-3.5Ag lead-free solders used in the electronics packaging industry were reinforced with different volume percentages of nano-size alumina and tin oxide particulates, respectively, to synthesize two new sets of nanocomposites. These composites were developed using microwave assisted powder metallurgy route followed by extrusion. The effects of addition of particulates on the physical, microstructure and mechanical properties of nanocomposites were investigated. Mechanical properties (microhardness, 0.2% YS and UTS) for both composite systems increase with the presence of particulates. The best tensile strength was realized for composite solders reinforced with 1.5 vol.% alumina and 0.7 vol.% tin oxide particulates which far exceeds the strength of eutectic Sn-Pb solder. The morphology of pores was observed to be one of the most dominating factors affecting the strength of materials. © 2008 MS&T'08®.