Phase equilibria in Ni-rich region of Ni–Cr–Hf system

Abstract

Phase equilibria in the Ni-rich region of the Ni–Cr–Hf system have been investigated at 1473 and 1273 K using electron microprobe and X-ray diffraction analysis. The phases involved are: Ni-rich solid solution (γ), Cr-rich solid solution (α), Ni₅Hf, Ni₇Hf₂, and Ni₃Hf. Ni₇Hf₂ shows a considerable solubility for Cr at 1473 K although this is reduced at 1273 K. Solid state phase equilibria were not in complete agreement with those previously thermodynamically calculated, but the form of the liquidus plan was confirmed.