Influence of Y2O3 particles on mechanical properties of magnesium and magnesium alloy (AZ91D)

Nowadays, research studies and industrial requirements are directed toward the goals of achieving environmental friendliness, energy savings, and reduced weight. Magnesium and magnesium alloys are well suited for structural and automotive applications owing to their lightweight. However, the reduced hardness and strength of these alloys do pose problems in exploiting their usage. These impediments of lightweight metal matrix can be alleviated by reinforcing hard-phase particles. Different volume percentages of Y2O3 particles (average grain size 5 mu m) were added as reinforcements in pure magnesium and magnesium alloy (AZ91D) and the composites were processed through the two-step stir-casting technique. Mechanical and metallurgical characterization studies were carried out on the stir-cast composites under as-cast and heat-treated conditions. Uniform distribution of yttria particles in magnesium and magnesium alloy matrix was observed through scanning electron micrographs. Macro and microhardness tests revealed the increased hardness with the increased amount of yttria reinforcement.