Phase Equilibria in the Ni–Rich Region of the Ni–Al–Zr System

ABSTRACTAlloys from the Ni–rich corner of the Ni–Al–Zr system have potential for use in high temperature, high strength applications. Such applications require a detailed knowledge of the high temperature phase equilibria.In the case of the Ni–Al–Zr system no isothermal sections have been published although the existence of a monovariant eutectic valley between Ni3Al and Ni7Zr2 has been established. An experimental determination of the phase equilibria in this system is being carried out using quantitative electron microprobe analysis (JEOL JSM–U3), xray diffraction and optical metallography. Partial isothermal sections are being determined for 1373K (1100°C) and 1273K (1000°C) and the resulting phase equilibria compared to that in the Ni–Al–Hf system determined previously.