Improvement in extrudability and mechanical properties of AZ91 alloy through extrusion with artificial cooling

摘要: Abstract This study demonstrates that the application of artificial water cooling during extrusion effectively increases extrudability AZ91 alloy and significantly improves mechanical properties extruded alloy. The dramatically reduces actual temperature deformation zone, which results in an increase maximum exit speed at is extrudable without occurrence hot cracking from 4.5 m/min to 7.5 m/min. It also promotes dynamic recrystallization precipitation behaviors extrusion, leads a reduction grain size amount fine Mg 17 Al 12 precipitates. As result, for 1.5 m/min, tensile compressive yield strengths improve by 51 MPa 114 MPa, respectively, its tension–compression asymmetry 0.73 1.02 owing refinement cooling. In addition, 7.5 m/min with exhibits finer structure than superior slower result indicates can simultaneously alloys.