Influence Of Hot Deformation On Properties Of AZ80 Magnesium Alloy

Magnesium alloys become the most developing potentialty of the material because of low density, high specific strength, good shock absorption of a series of outstanding features. How to improve the performance of magnesium alloy deformation becomes a research focus. AZ80 magnesium alloy shows the most excellent mechanical properties. In this paper, the deformation and heat treatment of two effective ways have combined extrusion experiment to improve the performance. Hot extrusion experiment, timing experiment and hot compression experiment have been done, the impactions of deformation and heat treatment on the properties and microstructure of AZ80 magnesium alloy have been studied by scanning electron microscopy (SEM) as well as conventional mechanical properties testing means, and the stress-strain relationship at high temperature. The main findings are as follows:Dynamic recrystallization happened in the process of hot extrusion, and formed small equiaxed grains, that refine the organization of AZ80 magnesium alloy .It plays useful role in enhancing properties of AZ80 magnesium alloy. With increasing temperature, the hardness of magnesium alloy increasing , and plastic decreasing; The tensile strength, yield strength, elongation, section contraction rate of AZ80 magnesium alloy is similar to the overall trend, with temperature increasing, mechanical properties increased first and then decreased, get to peak in the 170℃, tensile strength up to 255.51MPa, the yield strength up to132.62MPa . The analysis of the stress-strain behavior of AZ80 magnesium alloy can be drawn, AZ80 magnesium alloy The compression deformation is dynamic recrystallization, in all stress-strain curves, curve increased role soon because of the beginning stages of processing hardening, with the strain, dynamic recrystallization softening role intensified when its equilibrium and work-hardening effect, the stress reached a peak and then decreased gradually stabilized, and has entered a steady flow. In the same deformation temperature, strain rate corresponding to the higher value of greater stress, the strain rate at the same time as the increase in stress increased the peak strain moving in the same deformation rate, as the deformation temperature rises and the lower the stress value, the higher the temperature deformation, and the proliferation of atomic space for cross-slip fault, climb the driving force of the greater and therefore more prone to dynamic recrystallization. Through increased deformation temperature and lower deformation rate, magnesium alloy can quickly achieve dynamic recrystallization state, and this will benefit the grain refinement of magnesium alloy. Comprehensive analysis of the deformation of the heat treatment process can effectively improve mechanical properties of AZ80 magnesium alloy, and should be considered deformation temperature and deformation rate to determine the impact of the AZ80 magnesium alloy processing and heat treatment process.