Research On Bending-flattening Compound Deformation Of AZ31 Magnesium Alloy

Magnesium alloy has low density and high specific strength,and has wide application prospects in automobile coverings,aircraft and aeronautical equipment shells.However,magnesium alloys have the characteristics of close-packed hexagonal crystals,which lead to fewer sliding systems that can be operated at room temperature and difficult plastic deformation,which limits the application of magnesium alloy sheet.Therefore,how to improve the plastic forming properties of magnesium alloys at room temperature is the key prerequisite for expanding the scope of application of magnesium alloys.In this paper,the numerical simulation and experimental study of the bending-flattening composite deformation of AZ31 magnesium alloy sheet were performed,and the following results were obtained:(1)Deform-3D software was used to simulate the bending-flattening composite deformation process of AZ31 magnesium alloy.The stress field,temperature field and load of AZ31 magnesium alloy sheet after different composite deformation conditions are analyzed.(2)Developed a bending-flattening composite deformation mold and experimentally studied the composite deformation of AZ31 magnesium alloy.Studies have shown that the grain refining effect of magnesium alloy materials is the most obvious at a tooth pitch of 20 mm and a deformation temperature of 300℃,and the degree of refinement can reach 45.3%.(3)The mechanical properties of the magnesium alloy sheet after the bendingflattening composite deformation were tested.The mechanical properties of the plate were analyzed when the composite deformation condition was 30 mm tooth spacing and deformation temperature 420℃.Yield strength,tensile strength and elongation are improved compared to the original sheet.(4)Analysis of the texture evolution law after compound deformation,The results show that after the composite deformation,the texture strength on the {0001} crystal plane weakens.When the tooth spacing is 20 mm and the deformation temperature is 380℃,the texture weakening degree on the {0001} crystal plane is the largest,reaching 56.1%.