Phase equilibria and transformations in titanium aluminides

The phase equilibria in the binary Ti-al system are reviewed together with the transformations which occur involving aluminide phases of interest for the production of advanced high temperature materials. The difficulties enc ountered in the experimental determination of phase diagrams are highlighte d. The role of ternary alloying elements, notably oxygen and beta stabilisi ng elements, is discussed in relation to their effects on the phase equilib ria and transformations in aluminide based alloys. MST/4158.