Determination of the phase diagram of the molybdenum-nickel system using diffusion couples and equilibrated alloys

The phase diagram of the Mo-Ni system at 800-1295 Deg was studied by microscopy and electron-probe microanal. Equilibrated 2-phase Mo-Ni alloys contg. 7.9-83.0 at. % Ni and diffusion couples consisting of pure metals or their alloys were used to compare both methods. In both cases identical phase diagrams were found, which differ in details from those given by R. E. W. Casselton and W. Hume-Rothery (1964). The homogeneity range of the d-MoNi phase extends from 47.8-51.8 at. % Ni. The soly. limit of Mo in Ni is 28 at. % Mo at 1318 Deg and decreases with temp. by 2.3 at. %/100 Deg. The homogeneity region of the g-MoNi3 phase exists at compns. >75 at. % Ni. Exact boundary concns. are absent also for the b-MoNi4 phase. The soly. of Ni in Mo is .apprx.2 at. % Ni at 1295 Deg. [on SciFinder (R)]