Interface Evolution and Mechanical Properties of the Solid State Recycled Mg-Gd-Y-Zn-Zr Alloy During Rotary Extrusion

The Mg-7Gd-4Y-2Zn-0.4Zr scraps were solid state recycled through hot pressing sintering (HPS) and spark plasma sintering (SPS). Rotary extrusion with different parameters were conducted on the homogenized, hot-pressed sintered and spark plasma sintered alloy. The mechanical properties and microstructure evolution of the alloy fabricated by different processes were investigated. At 475 ℃ and rotational velocity of 1.2 rad/s, the homogenized alloy after rotary extrusion has the best mechanical properties. At 450 ℃ and rotational velocity of 2.4 rad/s, the hot-pressed sintered and spark plasma sintered alloy after rotary extrusion demonstrate better mechanical properties. With the increase of the extrusion temperature and rotational velocity, the mechanical properties of the alloy are improved. However, excessively high temperature and rotational velocity will cause the broken of bonding interface. The bonding interface of the alloy recycled by SPS is more stable than that of the alloy recycled by HPS, which is conducive to the improvement of mechanical properties of the recycled alloy.