Effect of Magnesium Addition on Microstructure and Mechanical Properties of Lead-Free Zinc-Silver Solder Alloys

摘要

Replacing the lead (Pb)-containing solders with the Pb-free solders in electronic products has been a global trend due to environmental and human health concerns for Pb toxicity. Many kinds of Pb free solder alloys have been proposed to date. Zinc (Zn) based Pb-free solder can be a promising alternative of Sn-Pb solder because of its competitive price and mechanical properties. In this research, Zn based solder alloys were developed by addition of silver (Ag) and magnesium (Mg) through conventional casting method. The changes in tensile strength, microhardness microstructure associated with the addition of relatively high melting point noble metal namely Ag were investigated in this work. Furthermore, the effects Mg addition on these mechanical properties and microstructure of the promising candidate Zn-Ag based alloys were extensively reported. Chemical composition of the alloys was confirmed by XRF analysis. A significant change in microstructure, microhardness and strength were found with the change of Ag content. A more interesting point is that the addition of Mg with Zn-Ag alloy increases the microhardness and strength to a large extent as well as ternary eutectic phases in the microstructures.