Effects of heat treatment on interface and mechanical properties of YAl2 reinforced Mg-14Li-3Al matrix composite

A YAl2p reinforced Mg-14Li-3Al matrix composite was prepared by stir-casting. The composite was subjected to heat treatment process at 623 K for 10 h. The effects of heat treatment on particle/matrix interface and mechanical properties were investigated by scanning electron microscopy (SEM), electron probe microanalysis (EPMA), nanoindentation and material tensile tests. The relationships among heat treatment, particle/matrix interface and mechanical properties of the composite were discussed. The results show that atom diffusion of yttrium and aluminum from the reinforcements to matrix may probably lead to the improvement of the transition interface layer between YAl2 particles and matrix, which is correlated to the increases both in tensile strength and ductility of the composite after heat treatment.