Characterization of phase transformation during hot compressive deformation in a β-stabilized Ti-45Al-7Nb-0.4W-0.15B alloy

A β-stabilized Ti-45Al-7Nb-0.4W-0.15B (at.%) alloy was hot deformed by uniaxial compression and the phase evolution during the compression was characterized with X-ray diffraction, scanning electron microscopy and electron probe microanalysis. The results show that modest deformation stress during hot compression restrains the γ → α transformation and the decomposition of β phase. The restrained γ → α transformation is a result of a modified equilibrium of the γ and α phases due to the applied stress, and the restrained β decomposition is a kinetic effect due to the decelerated diffusion of β-stabilizing elements caused by the compressive stress.