Role of Tungsten Disulfide Particles on the Microstructure, Mechanical, and Tribological Behaviors of Friction Stir-Processed Magnesium-Based Composite

Abstract

Influence of tungsten disulfide particles (WS2) on the friction and wear behavior of Mg-AZ91 forms the objective of this work. Friction stir processing (FSP) has been used to fabricate FSP AZ91/WS2 composite with various FSP passess. The microstructures were studied using a scanning optical microscope (OM), Electron Backscatter Diffraction (EBSD), and electron microscope (SEM). Hardness is measured using Vickers's microhardness tester. The impact of WS2 on the friction and wear resistance of Mg-AZ91 were evaluated using a pin on disc apparatus under dry sliding conditions. The microstructure showed the grain refinement of FSP AZ91/WS2 composite, due to severe plastic deformation and dynamic recrystallization. An increase in the FSP passess has transformed the grain size from micron to nano level. The hardness of FSP AZ91/WS2 composite is increased to 122 HV, from 62.2 HV0.3 of Mg-AZ91. The improvement in the hardness is due to reinforcement of WS2 and grain refinement. A significant improvement in the friction and wear resistance was achieved for Mg-AZ91 composites in contrast to FSP AZ91 and AZ91. SEM micro images showed the transfer of wear mechanism from severe adhesive wear to mild adhesive wear.

Microstructural Analysis & Tribology Characteristics of Magnesium Alloy AZ31B and Its Composites Using Machine Learning Modeling

“…Figure 11 shows SEM pictures of a low-wear surface and the debris that was produced under the conditions mentioned above. In general, the wear mechanisms that the composites are exposed to include abrasion, delamination, adhesion, and oxidation [36,37]. Numerous groves and scratches on the weathered surface were seen in Figs.…”