Fretting Fatigue Behavior of Magnesium Metal Matrix Composite Fabricated Through Friction Stir Processing Using Nickel Reinforced Particles

Abstract

In this research work, pure elemental Ni powder as reinforcement and AZ31 magnesium alloy as matrix were used to fabricate Magnesium metal matrix composite (MMC) by friction stir processing. The fretting fatigue test was carried out using 3-point bending setup to understand the material behavior under fretted condition. The plain fatigue test was also carried out for comparison. The volume fraction of the reinforcement was varied to fabricate the MMCs to get a homogeneous particle distribution. The microstructural features were observed using optical and scanning electron microscope which confirmed a proper bonding of reinforcement with the matrix and a homogeneous distribution of Ni particulates in the processed region at optimized parameters. The hardness and tensile strength of the alloy were improved using Ni reinforced particles into the matrix and helped to retain significant ductility. From the results, it is confirmed that the fretting fatigue life was significantly improved in case of MMCs produced at various volume fraction as compared to the as-received AZ31 magnesium alloy. Hence, the fatigue life can be enhanced by introducing Ni-reinforced particulates into the matrix. Fracture surfaces and fretted scars were also examined using SEM equipped with EDS to identify the failure mechanism. © 2022, ASM International.