Microstructure and twinning behavior of b.c.c tantalum under dynamic plastic deformation

In this paper, dynamic plastic deformation (DPD) of tantalum (Ta) was achieved by split Hopkinson pressure bar and a variety of DPD conditions were set to systematically investigate the microstructure of the deformed samples, focusing on the twinning behavior. Results showed that the deformation conditions have a significant effect on the number and distribution of {112}<111>twins. Compared with {100} and {111} grains, {110} grains are more prone to twinning due to the fewer slip systems. As the strain rate increases or the deformation temperature decreases, the number of twins increases dramatically. In addition, the texture of Ta samples gradually changes from {110} to mixed {100} and {111} textures with the increasing deformation, and the number of twins first increases and then decreases. After calculation, it is found that the selection of twin variants in Ta under DPD not only follows Schmid law but is also influenced by strain coordination. The research in this paper deepens the understanding of tantalum as a material for armour-piercing projectile.

Automated summary

Dynamic plastic deformation (DPD) of tantalum was investigated using split Hopkinson pressure bar, and the microstructure of deformed samples, especially the twinning behavior, was systematically studied under various DPD conditions. It was observed that the number and distribution of {112}<111> twins were significantly affected by the deformation conditions. {110} grains were found to be more prone to twinning compared to {100} and {111} grains due to the fewer slip systems. The number of twins increased dramatically with increasing strain rate or decreasing deformation temperature. The texture of the deformed tantalum samples changed gradually from {110} to mixed {100} and {111} textures, and the number of twins initially increased and then decreased. The selection of twin variants in tantalum under DPD was found to follow Schmid law and be influenced by strain coordination. The findings of this research deepen the understanding of tantalum as a material for armor-piercing projectiles.