High-Temperature Mechanical Properties of Zn-Based High-Temperature Lead-Free Solders

摘要

The effect of a minor addition of Ti on the mechanical behavior of Zn-25Sn-xTi (x=0wt.%, 0.02wt.% and 0.04wt.%) solder alloy at high temperatures of 80 degrees C, 100 degrees C, and 120 degrees C was investigated. The investigation revealed that Ti acted as nucleating agent. The grain size of the Zn-25Sn alloy was significantly refined with the addition of 0.02%Ti. The Zn-25Sn-0.02Ti exhibited the greatest elongation at all test temperatures. An excess addition of Ti (more than 0.04%) was found to cause the formation of ternary TiSn4Zn5 compounds, which is correlated with the degradation of elongation. The fractographs of the solders at high temperature revealed the presence of the TiSn4Zn5 compound in the dimple bottom, indicating that voids nucleated at the particles.