Effect of extrusion deformation on the microstructure and mechanical properties of Mg-4Zn-3Cu alloy
A DC casting Mg-4Zn-3Cu alloy billet was subjected to homogenization annealing at 420 ℃ for 24 hours.The effect of secondary extrusion deformation at different temperatures on the microstructure and mechanical properties of the alloy was systematically studied.The results indicate that ex-trusion processing can effectively improve the microstructure and mechanical properties of as cast Mg-4Zn-3Cu alloy.The alloy after extrusion deforma-tion has a large number of twinning,which is an important deformation mechanism in the alloy extrusion plastic deformation process.The alloy has the highest strength after secondary extrusion at 360℃,with a tensile strength of 277 MPa and a yield strength of 181 MPa.The strength of Mg-4Zn-3Cu alloy after secondary extrusion at 260℃ is lower,because the weakening effect of texture formed during low-temperature extrusion exceeds the strengthe-ning effect of grain refinement.