Mechanical properties of γ-TiAl cast alloys

Abstract

At present, much attention is being devoted to evaluation of the properties of γ-TiAl alloys in various structural states characteristic for the stage of their production (casting or powder metallurgy) and for subsequent treatment (deformation or heat treatment by various regimes). Specifically, in addition to preparing thin sheets, where the high toughness of the TiAl alloys is realized most efficiently, some works are devoted to casting articles and parts with a shape close to the final one. Therefore, it is of interest to investigate the properties of actual cast alloys in two conditions, namely, after crystallization with different cooling rates (in the initial state, with all the defects in the form of chemical inhomogeneities, micropores, different-sized grains, texture) and after complete degradation of the cast structure in the process of long-term operation at temperatures up to 1050°C. The paper concerns the properties and structures of cast and annealed γ-TiAl alloys alloyed with Hf, V, Mn, and B.