Effect of Annealing Treatment on Solid State Recycled Magnesium Alloy AZ91 D

A practical and important idea regarding solid state recycling of magnesium alloys is explored. Chips of AZ91D have been put in hot air environment for accelerated oxidation to simulate the to-be-recycled state of Mg alloy scraps. These chips materials received extrusion process and subsequent annealing treatment. Tensile tests showed that the extruded plate had higher strength than that of ordinary die cast counterpart. Micro-structure investigation indicated it was probably due to finer grains of the Mg matrix as a result of extrusion. Further annealing did not seem to alter this fine structure, yet it could diminish some un-favored form of Mg17A1, 2 compound. Thus, post-annealed solid state recycled AZ91D showed impressive strengths and elongations.