Microstructure and mechanical properties of SiC particles reinforced Mg-8Al-1Sn magnesium matrix composites fabricated by powder metallurgy

The new type of Mg-8Al-1Sn (AT81) magnesium matrix composites reinforced with different volume fractions (5, 10, 15, 20, 25 and 30 vol.-%) of SiC particles (average size of 10 mu m) was fabricated by powder metallurgy. With the increasing volume fraction of SiC particles (SiCp), the particles gradually show more homogeneous distribution. Compared with the AT81 alloy, the yield strength (YS) and ultimate compressive strength of the SiCp/AT81 composites are improved simultaneously. With the increasing SiCp from 0 to 30 vol.-%, the YS and ultimate compressive strength increase from 69 to 239 MPa and 286 to 385 MPa respectively, while the corresponding fracture strain (epsilon) decreases from 19.3 to 4.8%. The improvement of the YS and ultimate compressive strength of the SiCp/AT81 composites benefits from the more homogeneous microstructure due to the increase in the SiC particles.