INVESTIGATION ON TRIBOLOGICAL PROPERTIES OF AZ91 MAGNESIUM ALLOY METAL MATRIX REINFORCED WITH REDUCED GRAPHENE OXIDE (r-GO) AND HEXAGONAL BORON NITRIDE (hBN)

Metal Matrix Composites (MMCs) have emerged as vital materials across the space and transportation sectors including railways, roadways, aviation, and marine industries due to their broad range of applications in everyday human life.The greater emphasis on energy conservation, analysis, and related development has given lightweight materials global relevance. Because magnesium (Mg) and its alloys have a lower mass density, have greatly improved their prospective application in contemporary sectors. Although magnesium is a desirable light metal in the transportation sector, its use has been limited due to its poor strength and ductility. For any type of Metal Matrix composite (MMC), reducing the strengthening size allows for more favourable results, according to several highly praised reviews of the existing literature. The current investigation aims to analyze the tribological behavior of AZ91 magnesium alloy composites reinforced with hexagonal boron nitride (hBN) and reduced graphene oxide (r-GO). To evaluate the influence of these reinforcements, key tribological parameters such as Specific Wear Rate (SWR) and Coefficient of Friction (COF) are examined. The composite materials are synthesized through the stir casting process, with a focus on critical input factors including stirring speed and the weight fractions of r-GO and hBN. To optimize the tribological performance, Response Surface Methodology (RSM) is utilized to identify the best combination of input variables that results in minimal wear and friction. Tribological tests are carried out using a Pin-on-Disc setup under dry sliding conditions, following the ASTM G99-05 standard. Furthermore, Analysis of Variance (ANOVA) is employed to assess the statistical relevance of the experimental outcomes and to validate the reliability of the developed predictive models.