The Al-rich region of the Al-Mn-Ni alloy system. Part II. Phase equilibria at 620-1000 °C

Phase equilibria in the Al-rich region of the Al-Mn-Ni alloy system were studied at 1000, 950, 850, 750, 700, 645 and 620 °C. Three ternary thermodynamically stable intermetallics, the φ-phase (Al₅Co₂-type, hP26, P6₃/mmc; a = 0.76632(16), c = 0.78296(15) nm), the κ-phase (κ-Al_14.4Cr_3.4Ni_l.1-type, hP227, P6₃/m; a = 1.7625(10), c = 1.2516(10) nm), and the O-phase (O-Al₇₇Cr₁₄Pd₉-type, Pmmn, oP650,: a = 2.3316(16), b = 1.2424(15), c = 3.2648(14) nm), as well as three ternary metastable phases, the decagonal D₃-phase with periodicity about 1.25 nm, the Al₉(Mn,Ni)₂-phase (Al₉Co₂-type, P112₁/a, mP22; a = 0.8585(16), b = 0.6269(9), c = 0.6205(11) nm, β = 95.34(10)°) and the O₁-phase (base-centered orthorhombic, a ≈ 23.8, b ≈ 12.4, c ≈ 32.2 nm) were revealed. Their physicochemical behaviour in the Al-Mn-Ni alloy system was studied.