Constitutive Equation and Thermal Processing Map of TA18 Titanium Alloy under Induction Heating for Hot Compression
The research object is TA18 titanium alloy rod processed by forging.Using the Gleeble-3800 thermal simulation testing machine and simulating the process of induction heating,hot compression experiments were conducted at deformation temperatures of 820-900℃,strain rates of 0.1-10 s-1,and deformation amount of 80%to investigate their high-temperature mechanical behavior.An Arrhenius-type constitutive equation and Z parameter were used to establish a peak stress model for the high-temperature of TA18 titanium alloy.A dynamic material model was used to plot the thermal processing map,and a plastic instability map was constructed based on the Prasad instability criterion.The results indicate that,at a constant strain rate,the flow stress of TA18 titanium alloy decreases with increasing deformation temperature.Besides,TA18 titanium alloy shows positive strain rate sensitivity at a constant deformation temperature.When the strain rate is above or equal to 1 s-1,TA18 titanium alloy exhibits significant dynamic recrystallization behavior.The Arrhenius equation can effectively predict the variation of peak stress under different process parameters for TA18 titanium alloy.TA18 titanium alloy exhibits good hot workability within the deformation temperature range of 860-880℃and the strain rate range of 3-10 s-1.
NETL
NSTL
万方数据
