A study of the Al-rich part of the Al–Ni–Pt alloy system

Abstract

The Al–Ni–Pt phase diagram was studied in the compositional region from 50 to 100 at.% Al. Isothermal sections were determined at 1000, 900 and 790 °C. At 1000 °C the Al 2Pt phase was found to extend up to ∼Al 53Ni 23Pt 24 composition, separating the (Al 3Pt 2) and (Al 3Ni 2) phase fields. Two ternary structures were revealed. The one forming between ∼Al 75Ni 3Pt 22 and Al 75Ni 9Pt 16 is rhombohedral isostructural to Al 28Ir 9 and the other forming between ∼Al 73Ni 8Pt 19 and Al 72.5Ni 18Pt 9.5 has an orthorhombic ɛ 6 structure typical of Al–Pd and Al–Rh.