PHASE EQUILIBRIA IN THE ALUMINUM CORNER OF THE Al–Ti–Pt SYSTEM

Abstract

A series of physicochemical analysis techniques are employed to study the phase equilibria in the aluminum corner of the Al–Ti–Pt system at subsolidus temperatures and in alloy crystallization. It has been established for the first time that a ternary τ₁ phase (AuCu₃ structural type) forms by peritectic reaction L + <Ti₂Al₅> + <TiAl> ⇄ τ₁ at 1405 °С. On the solidus surface in the studied composition range at 1405, 1310, 1275, 1060, 925, 820, and 660 °С, there are seven isothermal planes that participate in invariant four-phase equilibria involving the liquid phase, three of them being peritectic and the others transitional.