Influence of silica rich HNT/MoS₂ hybrid reinforcements on mechanical, wear and corrosion characteristics of magnesium AZ31 alloy

Abstract

This article examines the effects of combining silica-rich Halloysite Nano Tube (HNT) and Molybdenum di Sulphide (MoS2) as hybrid reinforcements, dispersed at volumes of 2, 4, and 6%, on the surface of AZ31 alloy through the application of the friction stir process (FSP). The prepared composites were analysed to evaluate their microstructure, mechanical properties, wear resistance, and corrosion characteristics. Microstructural observations indicate the occurrence of rapid recrystallization, resulting in reduced grain size and uniform dispersion. The surface composite demonstrates an increasing trend in hardness with the addition of HNT, while hardness decreases with the inclusion of MoS2. The micro tensile test results exhibits that the composite exhibits an increasing trend in strength, while the micrograph of the fractured surface of the micro tensile specimens reveals reduced ductility. The composite displays enhanced wear behaviour with the increasing volume percentages of HNT and MoS2 particles. Solid lubricant nature of the secondary reinforcement and enhanced hardness due to HNT addition and FSP leads to higher wear resistance of the developed hybrid composite. Additionally, the corrosion rate decreases with the addition of HNT, whereas higher concentrations of MoS2 lead to increased corrosion.