Microstructural evolution of localized shear bands induced during explosion in Ti-6Al-4V alloy

Microstructures of the localized shear bands generated during explosion with a thick-walled cylinder specimen in Ti-6Al-4V alloy, were characterized by TEM and SEM. The results show that the twinning is a major mode of deformation, and the distortion-free grains in the bands with the size of 10 pm in diameter were proposed to be the re-crystallization during dynamic explosion. The further observations show that the alpha --> alpha(2) phase transformation may occur in the bands, and this kind of transformation could be confirmed by its dark field image and electron diffraction analysis. Analysis shows that there is specified orientation between the alpha and alpha(2) Phases.