The Role of Nano-SiC on Characteristics of Mg-Al-Sr/Nano-SiC Composites Produced by Stir Casting Route

Magnesium composite with Mg-Al-Sr matrix reinforced by nano-SiC has successfully fabricated by stir casting process. Addition of nano-SiC into magnesium matrix varies by 0.05; 0.10; 0.15; 0.20; and 0.25 in percent of volume fraction (Vf-%). The optimum mechanical properties are found in composition of 0.15 Vf-% nano-SiC. The number of hardness, impact toughness, and wear rate of this composition are 68.4 BHN, 0.065 Joule/mm², 1.03310⁻⁵mm³/mm respectively. Addition of 0.15 Vf-% nano-SiC enhances the hardness by 26%, impact toughness by 23.57%, and wear resistance by 38.40% respectively. Furthermore, the existence of nano-SiC in Mg-Al-Sr matrix modify the microstructure of composite by dispersing the intermetallic compounds. However, it is observed that higher nano-SiC content tends to agglomerate thus the strengthen mechanism cannot effectively occur. Microstructure analysis using OM and SEM reveals that the addition of nano-SiC transforms the dendritic matrix to globular equiaxed. EDX result predicts the phases formed are α-Mg, Al₄Sr, Mg₁₇Al₁₂, MgAlSr, and XRD analysis finds the existence of SiC, SiO₂. (paper)