Abstract:

We addressed the impact of extrusion ratio on microstructure and mechanical properties of AZ31B Magnesium alloy. We applied optical microscopy ( OM) to the observation of its microstructure, examined its mechanical properties by indoor temperature tensile and compressive test, and observed its fracture morphologies by scanning electron microscopy ( SEM) . Results show that its microstructure changes from partially dynamic recrystallization to completely dynamic recrystallization with the increase of extrusion ratio. Its tensile fracture varies from mixed fracture to obvious ductility fracture. Compressive fracture is converted from cleavage fracture to quasi-cleavage fracture. Through high extrusion ratio, we can obtain fine and homogeneous microstructure and good comprehensive mechanical properties, tensile strength of 310 MPa, yield strength of 200 MPa and elongation rate of 14%. Asymmetry of tensile and compressive strength is reduced, which is therefore benefit for secondary plastic machining of Magnesium alloy.

Key words: hot extrusion, mechanical properties, AZ31B Magnesium alloy')">AZ31B Magnesium alloy, microstructure, extrusion ratio