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

Abstract

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