Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : March 17, 2018 - March 18, 2018
The purpose of this study is to investigate the effect of Bi addition to Ag-free and low Ag lead-free solder on their mechanical properties. Sn-0.7mass%Cu (SC07) and Bi (1 and 2 mass%) added to their alloys were used in this study. Tensile tests and low cycle fatigue tests for their specimens were carried out at room temperature (25°C) under 1.0× 10-3 and 1.0×10-1 s-1 strain rate. After these tests, microstructures of their specimens were observed by OM and SEM, and their elements were analyzed using EPMA. The strain rate increases with the tensile strength and elongation increase similar to SAC alloys. The addition of Bi into SC07 caused an increase in their tensile strength and fatigue strength. This is because Bi dispersed uniformly in the specimens and also dissolved in the primary Sn as a solid solution. The addition of Bi has effect on fine primary Sn grains.
