The phase equilibria in the Au–In–Ga ternary system

• The Au–In–Ga ternary phase diagram was experimentally investigated.
• XRD, DTA, SEM and EDS techniques and a CALPHAD prediction were implemented.
• A previously unknown ternary phase was identified.
• Using DTA results, a number of key reactions were identified and discussed.

The phase equilibria of the Au–In–Ga system were investigated for the first time using Differential Thermal Analysis (DTA), X-Ray Diffractometry (XRD), Energy Dispersive X-ray Spectroscopy (EDS) and Scanning Electron Microscopy (SEM). A new ternary phase (Au2InGa2) with the hexagonal structure (P63/mmc) was discovered which melts incongruently at 394 °C. From the experimental results, several invariant reactions have been identified and discussed.