Evolution of Microstructure and Mechanical Properties of ZK80 Mg Alloy during Net-Shape Pressing of Extruded Perform

The microstructure and mechanical properties of as-cast ZK80 Mg alloy during net-shape forming of tensile specimens with close-die pressing extrusion, and the effect of extrusion-forging on the fracture mechanism of ZK80 alloys were studied in the present investigation. The results indicated that Rm (σb)、Re (σs) and A(δ) of compound forming ZK80 Mg alloy had noticeable improvement. Large deformation and produce twins, lead to grain refinement and had strongly influence on mechanical property of ZK80 Mg alloy, as well as strong affected the mechanical properties of the alloy. It was found that as-cast ZK80 Mg alloy has mixed fracture characteristics including cleavage fracture, intergranular facture and ductile fracture. As-extruded perform and as-close die ZK80 Mg alloys were obvious dimples for ductile fracture pore nucleation mechanism.