Constitutive Model for Molybdenum-Niobium Alloy During Hot Deformation

Isothermal compression of the molybdenum-niobium alloy was conducted on a Gleeble-3800 thermal simulator at the deformation temperature range of 1100-1300 degrees C with strain rates ranging from 0.001 to 10 s(-1) and height reduction of 50%. The results show that the deformation temperature and strain rate affected the flow stress during the thermal deformation of molybdenum-niobium alloy significantly. The true stress-strain curves exhibit a peak flow stress, flow softening and steady flow behavior. The activation energy (Q) and stress exponent (n) of molybdenum-niobium alloy, are calculated. The constitutive equation is established based on a hyperbolic-sine equations of Arrhenius type.