Fabrication and Investigation of Mechanical and Dry Sliding Wear Characteristics of Al6061-Si3N4 Composites

ABSTRACT Aluminum based metal matrix composites (MMCs) are excellent grade engineering materials used in high-tech applications like aerospace, automotive, marine, and other applications, owing to their higher specific strength, better physical and mechanical characteristics, coupled with lower density, when compared with pure aluminum and its alloys. The present paper emphasizes experimental work that was carried out on the fabrication of Al6061 alloy reinforced with different weight percentages (wt%) of silicon nitride (Si3N4) MMCs. The vacuum-assisted stir casting technique was used to fabricate Al6061-Si3N4 composites. The wt% of Si3N4 reinforcement was varied from 0 to 6 wt% in steps of 2. The optical micrograph (OM), density, energy dispersive spectroscopy, and mechanical characteristics such as resistance to indentation, ultimate tensile strength, percentage elongation, and scanning electron micrographs of the composites before and after tensile and wear tests have been investigated. The tribological studies for the determination of wear properties of developed composites were carried out with respect to volumetric wear loss, sliding distance, and applied load, with increasing Si3N4 reinforcement content in Al6061 alloy. The density of Al6061-Si3N4 composites has improved with increased reinforcement content as compared to monolithic alloy. The OM and scanning electron micrographs reveal a uniform distribution of Si3N4 particulates in the matrix alloy. The mechanical properties along with the resistance to the wear property have improved, and there was a noteworthy loss in the ductility of Al6061-Si3N4 composites in comparison with Al6061 alloy.