Effects of lamellar α thickness on dynamic mechanical properties and sensitivity to adiabatic shear banding of TC21 alloy

The α lamellar microstructures with different thicknesses were obtained by proper heat treatments of TC21 alloy, and the dynamic mechanical properties and sensitivity to adiabatic shear banding were investigated by the Split Hopkinson Pressure Bar. The results show that the thickness of lamellar α increases from 0.57 to 6.49 μm with the decreasing of the cooling rate. Under the dynamic compression condition, the dynamic strength decreases as the thickness of lamellar α increases; while the dynamic strain exhibits an opposite trend. Under the dynamic shear condition, the sensitivity to adiabatic shear banding increases with the decreasing of the thickness of lamellar α at the same impact velocity, and the sensitivity to adiabatic shear banding increases for the same microstructure with the increasing of impact velocity.