Thermodynamic and experimental study of Ti-Ag-Cu alloys

Phase equilibria in the ternary Ti-Ag-Cu system have been studied thermodynamically and experimentally at various temperatures. The thermodynamic analysis was performed by combining the most recent data on the binary Ag-Cu, Ti-Ag and Ti-Cu systems and experimental information obtained by the diffusion couple technique. The eutectic and three noneutectic binary Ag-Cu alloys were melted and annealed in evacuated Ti ampoules at temperatures of 900, 950 and 1000 °C for various times and subsequently quenched in water. Both the calculations and the experimental results confirm that in the ternary system there is a miscibility gap, which divides the liquid phase into solutions of low and high Ti content. Furthermore, no ternary compounds were found. Several isothermal sections and the activity of titanium as a function of the copper-tosilver ratio and temperature are presented.