Phase equilibria in Al-Ni-Zr system at 1123 K

Phase equilibria in ternary Al-Ni-Zr system have been studied using X-ray phase and electron probe microanalyses at 1123 K in the content range of 0–45 at % Al. A fragment of the isothermal section of this system has been plotted. The existence of three-phase equilibria Zr₇Ni₁₀ + Zr₈Ni₂₁ + Zr₂Ni₇, τ₂-ZrNi₂Al + NiAl + Zr₂Ni₇, NiAl + Ni₃Al + Zr₂Ni₇, Zr₇Ni₁₀ + Zr₂Ni₇ + τ₂-ZrNi₂Al at 1123 K has been established for the first time. Phase based of binary compound Zr₂Ni₇ dissolves up to 13 at % aluminum. The crystalline structure of the τ₇-Zr₅Ni₄Al phase has been determined, including structure type U₃Si₂, spatial group P4/mbm (a = 7.1852(7) Å, c = 3.3019(5) Å).