Characterization of Hot Deformation Behavior for Pure Aluminum Using 3D Processing Maps

The hot compressive deformation behavior of pure aluminum has been investigated at different conditions of strain rate range of 0.005-10 s^-1 and temperature range of 523-823 K. Based on dynamic materials model Malas criterion, processing maps were constructed to evaluate the efficiency of energy dissipation and flow instability regions. The optimized condition was around strain rate of 0.005-0.01 s^-1 and temperature of 773-823 K with peak energy dissipation efficiency of 42%. Meanwhile, the rule of strain hardening exponent, strain rate sensitivity exponent and temperature sensitivity exponent have been studied, then 3D processing maps considering the strain variable was developed, and the energy dissipation maps and the dynamic instability maps were changed with the strain increasing. Results showed that region at strain rate of 10s^-1 and the region at temperature of 823 K, strain rate of 0.005s^-1 showed high-energy dissipation rate. The 3D dynamic instability maps showed instability region of different parameters, the proper process parameters was ought to be kept away from this region. The conditions of the cracking microstructure occurred proving that the region was determined by the 3D instability maps.