Hot Compression Mechanism and Comparative Study on Constitutive Models of Mo-3 vol%Al2O3 Alloys

The hot compression tests for Mo-3 vol.%Al2O3 alloys were conducted on a Gleeble-1500D thermo-mechanical simulator in the temperatures range of 1000-1300 degrees C and strain rates range of 0.005-1 s(-1). The hot deformation behavior, mechanism associated with microstructure evolution of Mo-3 vol.%Al2O3 alloys was investigated by electron backscattering diffraction analysis. Three types of stress-strain curves were analyzed by quantifying the work hardening rate. The deformation mechanism at 1000-1300 degrees C mainly included the plastic deformation of Mo-3 vol.%Al2O3 alloy, as well as the dynamic recovery and recrystallization of Mo matrix. The modified Arrhenius, Modified Johnson-Cook and modified Zerilli-Armstrong constitutive equations were established and evaluated by the correlation coefficient (R-c) and average absolute relative error ((e) over bar). The flow stress of Mo-3 vol.%Al2O3 alloys could be well predicted by those three constitutive models, but modified Arrhenius constitutive model had a higher predicated accuracy