Taylor-Quinney Coefficient of TA2 Pure Titanium Under Dynamic Tension
Metal plastic heat dissipation is still an unsolved problem.For example,the experimental results of the work-heat conversion coefficient and its strain and strain rate correlations are not consistent in the existing literatures.The heat dissipation characteristics of commercial purity titanium TA2 during tensile process were studied at 0.1-100 s-1 strain rate.Digital image correlation(DIC)and infrared temperature measurement synchronous test system were used to analyze the deformation and temperature field evolution of plate tensile specimens.The results show that when the strain rate is greater than 1 s-1,the sample is approximately adiabatic before tensile necking.The Taylor-Quinney coefficient β of TA2 is not sensitive to the strain rate effect,which is not a constant and evolves with strain.In the initial stage of loading,β increases with the increase in strain,and reaches the maximum value of 0.92 when the tensile strain is about 0.08.Then,β decreases gradually with the increase in strain,and it decreases to about 0.8 at strain of 0.3.The EBSD microscopic analysis of the specimens at different deformation stages indicates that the variation of Taylor-Quinney coefficient is related to the twinning and microstructure evolution during the deformation process.