Thermodynamic assessment of the Cr–Ti and first assessment of the Al–Cr–Ti systems

Abstract

A re-assessment of the thermodynamic parameters of the binary Cr–Ti system and a first assessment of the ternary Al–Cr–Ti system were performed. The new Cr–Ti description contains all three modifications of the Laves phases ( α-TiCr 2, β-TiCr 2, γ-TiCr 2) and the calculated binary phase diagram is in very good agreement with the experimental data. For a first assessment of the Al–Cr–Ti system, the present Cr–Ti description was used as the constituent binary and the thermodynamic parameters of the α 2–Ti 3Al, β, τ and Laves phases were optimized. Calculations using the new thermodynamic description for the ternary system are in good agreement with experimental work showing the ternary extension of the γ-Ti(Al,Cr) 2 phase at 33 at.%Ti, the solidification of the τ phase, and the order disorder transition of the β phase.