Capturing of the propagating processes of adiabatic shear band in Ti–6Al–4V alloys under dynamic compression

Abstract

In the present investigation, the dynamic compression properties and the sensitivity of the formation of adiabatic shear band in the Ti–6Al–4V alloyshaving equiaxed and bimodalmicrostructures were studied. The stop-ring technology traditionally used on the hat-shaped specimen was introduced to the compression experiments to control the engineering strain of the cylindrical specimen. The loading time (ti), the critical strain (εi) and the localization energy (Uloc) at which adiabatic shear band initiates were differentiated. The loading time (ti), the critical strain (εi) and the localization energy (Uloc) analyzed were found to be useful points in decoupling the homogenous plastic deformation and the adiabatic shear banding behavior in the dynamic deformation and fracture behavior of the investigated Ti–6Al–4V alloys. The loading time (ti), the critical strain (εi) and the localization energy (Uloc) were also chosen to quantitatively evaluate the sensitivity of the formation of adiabatic shear band in Ti–6Al–4V alloys having bimodal microstructures with identical primary equiaxed α and similar volume fraction of the transformed β matrix. The bimodal microstructure BA with the thickest α lamellar in the transformed β matrix demonstrated the lowest possibility of the formation of adiabatic shear band.