Structural and mechanical properties of amorphous Si3 N4 nanoparticles reinforced al matrix composites prepared by microwave sintering

Abstract

The present study focuses on the synthesis and characterization of amorphous silicon nitride (Si3 N4) reinforced aluminum matrix nanocomposites through the microwave sintering process. The effect of Si3 N4 (0, 1, 2 and 3 wt.%) nanoparticles addition to the microstructure and mechanical properties of the Al-Si3 N4 nanocomposites were investigated. The density of Al-Si3 N4 nanocomposites increased with increased Si3 N4 content, while porosity decreased. X-ray diffraction (XRD) analysis reveals the presence of Si3 N4 nanoparticles in Al matrix. Microstructural investigation of the nanocomposites shows the uniform distribution of Si3 N4 nanoparticles in the aluminum matrix. Mechanical properties of the composites were found to increase with an increasing volume fraction of amorphous Si3 N4 reinforcement particles. Al-Si3 N4 nanocomposites exhibits higher hardness, yield strength and enhanced compressive performance than the pure Al matrix. A maximum increase of approximately 72% and 37% in ultimate compressive strength and 0.2% yield strength are achieved. Among the synthesized nanocomposites, Al-3wt.% Si3 N4 nanocomposites displayed the maximum hardness (77 ± 2 Hv) and compressive strength (364 ± 2 MPa) with minimum porosity level of 1.1%.