The effect of Cr and Zr on the structure and phase composition of TNM gamma titanium aluminide alloy

摘要: Abstract Quantitative analysis of the zirconium and chromium cooperative effect on structure phase composition, after solidification heat treatment, TNM type alloy, was performed using both experimental techniques thermodynamic calculations. It is shown that joint alloying by up to 1 at.% does not change sequence transformations during subsequent cooling alloy. Rather, it significantly decreases α2-phase amount increases β-phase amount. Increasing associated with a high beta-stabilizing chromium, whose partition coefficients k(β/γ) k(β/α) are higher than 1 (ranging from 1.67 3.8). Zirconium distributed quite uniformly close 1. HIP treatment alloy at 170 MPa 1250 °C leads significant reduction α(γ/α2)-phase fraction, γ-globular in comparison vacuum annealing 1250 °C. The content softest decrease hardness 365 HV 333 HV, total elongation 0.5% 0.8% room temperature substantially ultimate tensile strength 750 MPa 715 MPa.