Microstructural and mechanical characterisation of WE54–SiC composites

Microstructural and mechanical characterisation of WE54 alloy reinforced with SiC particles of two sizes is studied. All the materials are produced by powder metallurgy. The composite microstructure is characterised by ultrafine magnesium grains with SiC and β particles located at the grain boundaries. The composites show better mechanical strength than the unreinforced alloy. The greater yield stress of the composites is due mainly to grain refinement and an increase in the dislocation density as a result of CTE mismatch between matrix and ceramic particles. The high-temperature mechanical strength of the composites is controlled by deformation of the matrix.