Microstructure, Mechanical and Ignition Characteristics of Si3N4 Reinforced Magnesium Matrix Nanocomposites

Lightweight magnesium-based materials have received attention in the automobile sector as a solution to minimize fuel consumption and greenhouse gas emissions. Magnesium has great weight-reduction potential in the aerospace sector, but its low ignition temperature limits its utilization. Improving magnesium’s ignition resistance is critical for aerospace applications. The present study developed Mg/Si3N4 nanocomposites to improve the ignition resistance to address this limitation. The nanocomposites were prepared by ultrasonically-assisted stir casting with 0.5, 1, and 1.5 vol% Si3N4 nanoparticles. The effect of Si3N4 nanoparticles on the ignition and compression characteristics was examined. SEM micrographs showed the homogeneous dispersion of Si3N4 nanoparticles with negligible clustering. Notably, the nanocomposites’ ignition resistance was increased by increasing the vol% of the Si3N4 nanoparticles. Adding 1.5 vol% Si3N4 nanoparticles resulted in the highest ignition temperature of 614 °C, 34 °C higher than pure magnesium. Similarly, the compressive properties were enhanced with the progressive addition of Si3N4 nanoparticles. The inclusion of 1.5 vol% Si3N4 nanoparticles resulted in a maximum compressive yield strength of 118 MPa and ultimate compressive strength of 323 MPa.