Effect of reinforcing phase inherited from another composite on the mechanical properties of cast magnesium base composite

摘要

Cast magnesium-base composite reinforced by in-sku Al_3 Ti and A1_2O_3 has been synthesised by inheriting the reinforcing phases from cast aluminium-base composite, which has been processed by dispersing TiO_2 particles into the molten aluminium. The effects of reinforcing phases and processing temperature on microstructure and mechanical properties of the resulting composites have been investigated separately. Brinell hardness has increased with increased volume fraction of reinforcing intermetallics, Al_3Ti, and ceramic particle content. But, it has decreased gradually with increased processing temperature. The ultimate tensile strength has increased with increased processing temperature, but the percentage elongation has decreased slightly with increased processing temperature. The tensile properties, ultimate tensile strength and percentage elongation, in the composites have decreased with increased porosity. Ultimate tensile strength and percentage elongation in the composites, extrapolated to zero porosity, have decreased with increased particle content.