Consolidation behavior of Mg-10Gd-2Y-0.5Zr chips during solid-state recycling

Unlike that of sintering of fine powders, chips are consolidated by hot deformation in the solid-state recycling. In this work, conventional extrusion (CE) and cyclic extrusion compression (CEC) are used to investigate single and multi-passes shear deformation on the consolidation of chips during solid-state recycling. The results show that utilization of Mg chips with smaller specific surface area (i.e. coarser powder) contributes to easier solid-state bonding because of the decrease in specific surface area which promotes suppression of oxide contamination in the recycled specimens. Enhanced consolidation of chips is not only ascribed to the physical mechanisms caused by plastic deformation, but also to atom diffusion between chips triggered by shear plastic deformation at elevated temperatures. Multi-passes shear deformation breaks the oxide films easier into small particles which are dispersed within the grains or at grain boundaries. It is postulated that the shear deformation of chips is responsible for the better consolidation of chips by high-temperature deformation.