Compression properties of Ti-Al-X alloys in relation to site occupancies of alloying elements in TiAl and Ti3Al

Room temperature compression properties of Ti-51Al-(1 similar to 2)X and Ti -26Al-(1 similar to 2)X alloys (X=V, Cr, Mn, Fe, Co, Ni, Zr, Nh, Mo, Ta, Ga or Sn) were measured in order to examine how the compression deformability correlates with the site occupancies of the alloying elements in gamma-TiA l and alpha(2)-Ti3Al. The results showed that, for the gamma phase, the com pression ratio is not related to the site preference of the alloying elemen ts in a simple way. For the alpha(2) phase, the following correlation was o bserved between the compression ratio and the site occupancies of the inves tigated elements, those which occupy Al sites decrease the deformability, w hile those occupying Ti sites (except V) improve the deformability of the a lpha(2) phase. Compression properties of dual-phase TiAl alloys based on Ti -46Al-(1, 3, 5)X were also measured at room temperature to test a hypotheti cal mechanism of ductilization based on mechanical compatibility at phase i nterface. It was concluded that no simple relationship exists between the d eformability of the dual-phase alloys and the properties of their constitue nt phases.