Shear strength of the Zn–Sn high-temperature lead-free solders

Abstract

This study examines the shear strength behavior of the high-temperature Zn–20 wt% Sn, Zn–30 wt% Sn, and Zn–40 wt% Sn solders in the temperature range of 298–425 K. The results showed that increasing the Sn content of the alloys decreases both shear yield stress (SYS) and ultimate shear strength (USS) at all test temperatures. This can be attributed to the higher volume fraction of the softer β-Sn matrix and the eutectic α-Zn + β-Sn structure, which replaces the colonies of the harder α-Zn phase in the microstructure. The high shear strength of these high temperature solder alloys makes them suitable for application in harsh environments.