正挤压-弯曲剪切变形对AQ80镁合金组织及性能影响

The AQ80 magnesium alloy sheet was prepared by a new process of direct extrusion and bending-shear deformation. The microstructure, grain size and second phase in the extrusion process were analyzed by optical microscopy (OM) and scanning electron microscopy (SEM). The test methods such as X-ray diffractometry (XRD) and universal tensile testing machine were used to study the texture and mechanical properties of AQ80 magnesium alloy. The results show that complete dynamic recrystallization of AQ80 magnesium alloy occurs in direct extrusion and bending-shear deformation, the uniform fine-grained structure with an average grain size of about 2.5 μm is finally formed. The precipitated phase in AQ80 magnesium alloy promotes the occurrence of dynamic recrystallization and inhibits the grain growth with the precipitation strengthening effect. The base texture is weakened and the comprehensive mechanical properties of AQ80 magnesium alloy are excellent after extrusion. The yield strength and the tensile strength are up to 359 and 370 MPa, respectively, compared with those before extrusion, the tensile strength is increased by 13.8% and the elongation is increased to 18%.