Superplasticity and Cavitation of Recycled AZ31 Magnesium Alloy Fabricated by Solid Recycling Process

Superplastic behavior and cavitation have been investigated for the solid recycled AZ31 magnesium alloy made of machined chips. The elongation to failure of the solid recycled specimen was lower than that for the extruded specimen from a virgin block (virgin extruded specimen) at elevated temperature, although the strain rate sensitivity for the solid recycled specimen was the same as that for the virgin extruded specimen. The volume fraction of cavities and the total number of cavities for the solid recycled specimen were larger than those for the virgin extruded specimen. Moreover, cavity nucleation occurred not only at grain boundaries, but also in the grains for the solid recycled specimen. It is suggested that contamination of oxide particles at grain boundaries and in grains promotes cavity nucleation in the solid recycled specimen and adversely affects the elongation to failure.