Investigation of microstructure, mechanical properties, and wear behavior of aluminum A380 nanocomposite reinforced with graphene nanosheets produced by spark plasma sintering technique

Abstract

The study reports the development of graphene nanosheets reinforced aluminum A380 matrix nanocomposites using powder metallurgy. Nanocomposites are fabricated by a mechanical alloying process and the bulk nanocomposites are prepared by spark plasma sintering (SPS) technique in a vacuum at 540 °C. 0.25 wt%, 0.5 wt%, 0.75 wt%, and 1 wt% of graphene nanosheets are used as a refinement for nanocomposites. Microstructural, mechanical properties, and wear behavior of the Al A380–graphene nanocomposites were investigated. Testing and analysis of fabricated composites revealed an improvement in hardness (59.96%) and wear rate (108.57%). Grain refinement action caused by graphene, high hardness, and graphene's self-lubricating nature is reasoned for these improvements. Optical microscopy and scanning electron microscopy (SEM) analysis were used to investigate microstructures of the nanoparticle distribution in the nanocomposites of the SPS samples. The wear resistance of resultant composites is reported at a higher side, decreasing friction coefficient owing to graphene's self-lubricating nature. Moreover, the incorporation of lubricant graphene nanosheets significantly reduced the wear rate and the friction coefficient in comparison with the Al A380 matrix composites. Wear morphology is characterized using SEM. In the end, the Al A380–0.5% graphene nanocomposite sample represents the greatest hardness and wear behavior, and good microstructure to compare with the other experimented samples.