Ballistic targets made of Ti6Al4V, which had undergone various heat treatments, were impacted by 7.62 mm armour piercing bullets, thus being subjected to strain rates of about 3 × 105s-1. The adiabatic shear bands formed thereby were examined using optical and transmission electron microscopy. The high temperatures generated at the shear band can cause transformation from the α phase to the β phase and may lead to melting in some cases. The rapid cooling of the highly deformed shear bands was of the order of 107°C s-1. This extremely high rate produced a very fine transformed structure. Bands that melted on heating differed from those whose temperature rose only to the β region. In the former all previous features have disappeared; in the latter the primary β lamellae were preserved and they served to indicate the direction and extent of the shear at any point within the band. In both cases the transformation products are harder than the base material.
ASJC Scopus subject areas
- Engineering (all)