An Assessment of the Peak Temperature in the Adiabatic Shear Band of Ti-6A1-4V Based on the Measured Shear Stress and Local Strain

The appearance of the discontinuous strain in the outer surface of a specimen does not indicate the just formation of the adiabatic shear band. The phenomenon is believed to be a result of the further development of the deformed adiabatic shear band. For calculating the peak temperature in the adiabatic shear band, the elastic shear strain should be extracted from the local shear strain because the elastic part does not contribute to the plastic work. The peak temperature in the adiabatic shear band in a Ti-6A1-4V specimen (TA-50) in dynamic torsion is calculated. It is divided into 3 parts: ambient temperature and temperatures caused by homogenous and inhomogenous shear strains, respectively. In two cases (the elastic shear strain is extracted from the local shear strain or not), the calculated temperature values are 669 degrees C and 665 degrees C, which are in the range of the thermal recovery/recrystallization temperature and do not exceed the phases transformation temperature. The calculated results in the paper are higher than the calculated result of 630 degrees C by Liao and Duffy (1998). If the relation between the shear stress and the local plastic shear strain is not completely clear, an appropriate approximation is necessary.