Solidus surface of the Al–Ti–Pd system in the Al–AlPd–TiPd–Ti region

Abstract

The Al–Ti–Pd system has been studied by microstructural analysis, electron microprobe analysis, x-ray diffraction, and differential temperature analysis in the composition range 0–50 at.% Pd (Al–AlPd–TiPd–Ti partial system) at subsolidus temperatures. The solidus surface of the system is constructed for the first time. At subsolidus temperatures, there are two ternary compounds, τ1 (Al61Ti26Pd13, AuCu3 type) and τ3 (Al44Ti35Pd21, MgZn2 type), a continuous solid solution (β0 phase) between isostructural (CsCl type) high-temperature modifications of AlPd and TiPd equiatomic phases, and terminal solid solutions based on β-Ti and α-Ti and TiAl, Ti2Al5, TiAl3, and Al3Pd2 binary compounds and e phase. The above-mentioned phases participate in 11 four-phase invariant equilibria involving the liquid phase and are represented by isothermal tie-line triangles in the temperature range between 630 and 1205°C.