Microstructure and flow behavior of 2A14 aluminum alloy during hot deformation

The flow stress behavior of 2A14 alloy during hot compression deformation was investigated by thermal simulation experiment at the temperature range of 350-480 ℃ and the strain rate range of 0.001-10 s-1 with Gleeble-3500 thermal simulation machine. The deformation microstructures were observed by optical microscopy(OM) and transmission electron microscopy(TEM). The results show that the elongated grains coarsen with decreasing strain rate and increasing temperature. The partial recrystallization takes place in the alloys deformed at high temperature or low strain rate. The main soften mechanism of the alloy transforms from dynamic recovery to dynamic recrystallization. The flow stress reduces with the increasing deformation temperature and decreasing strain rate. The flow stress of the alloy during hot compression deformation can be described by constitutive equation in hyperbolic sine function and can also be described by Zener-Hollomon parameters, and the hot deformation activation energy is 173.375 kJ/mol.