Integrated Extrusion–Shear Forming Process of the Solid-State Recycled AZ80 Magnesium Alloy via Hot Press Sintering

Abstract

The consolidation recycled AZ80 billets were successfully fabricated through the cold press and hot press sintering of the AZ80 metal chips. The consolidation recycled billets sintered at 350 °C present the comparable compressive properties and inferior tensile properties compared with the initial cast billets. The defects in the consolidation recycled billet were inclined to propagate along the bond interface between the metal chips during tension, which resulted in the inferior tensile properties of the recycled billets. The recycled billets were then subjected to the integrated extrusion–shear (ES) process. The homogeneous finer dynamic recrystallization grains with an average grain size of 6 μm can be obtained in the shear deformation zone and extrusion sizing zone through integrated ES process at 300 °C with an extrusion velocity of 0.6 mm/s. The recycled billets after integrated ES forming process present rival tensile properties compared with the initial cast billets after integrated ES forming with the same extrusion parameters, which can be ascribed to that the integrated ES forming can nearly eliminate the defects through the severe compressive and shear strain. The solid-state recycling process through hot press sintering and subsequent integrated ES process can fabricate the consolidation recycled AZ80 rod, which demonstrates the comparable tensile properties with the cast–extrusion rod.