Wetting characteristics of Sn-Ag-Cu solder on Pd-based metallic glass

A feasibility study has been conducted to determine whether soldering process can be used for the joining of metallic glasses. The mechanical properties of metallic glasses are extremely attractive compared with conventional crystalline materials. In order to adopt bulk metallic glasses in a broader range of engineering applications, it is very important to establish appropriate joining processes of metallic glasses. During the joint of metallic glass, the most serious issue is the reformation of glassy phase at the high temperature area. Therefore, to avoid the recrystallization of glassy phase, the soldering process has been investigated to join metallic glasses. In this study, the spread test was mainly performed at 523 K for 60 s. Results showed that the Sn-3.0 mass%Ag-0.5 mass%Cu solder deposited on Pd-based metallic glass had better wetting characteristics than the Sn-57 mass%Bi and Sn-51 mass%In solders. The microstructure at the interface between Sn-3.0Ag-0.5Cu solder and Pd-based metallic glass was analyzed by scanning electron microscopy. It was clear that the intermetallic compound, PdSn₄ phase, was formed at the interface.