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

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 (t_i), the critical strain (ε_i) and the localization energy (U_loc) at which adiabatic shear band initiates were differentiated. The loading time (t_i), the critical strain (ε_i) and the localization energy (U_loc) 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 (t_i), the critical strain (ε_i) and the localization energy (U_loc) 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 B_A with the thickest α lamellar in the transformed β matrix demonstrated the lowest possibility of the formation of adiabatic shear band.