Exploring the Influence of Dry Sliding Wear Test Parameters on the Wear Mechanisms of Structural Eco-Composites Along With Microstructural Analysis

Abstract

This research aims to assess the enhancements in tribological performance of a stir-cast aluminum hybrid composite (AA6082-T6 with 4 wt% fly ash and 3 wt% alumina). The wear properties of the composite were evaluated as functions of load, sliding speed, and duration under dry sliding conditions at room temperature using a pin-on-disk tribometer. A combined optimization of specific wear-rate (SWR) and coefficient of friction (COF) was carried out using the response surface methodology with a desirability approach, alongside regression models for individual responses. The accuracy of these models was verified through confirmatory testing. The developed mathematical models offer deeper insights into the complex interactions between the wear performance of the composite materials and the variables influencing the two-body wear system. The wear behavior of the composites under dry sliding conditions was examined through the development of wear maps that analyzed the regions of wear mechanisms as they progressed with varying loads and sliding speeds. A linear increase in the SWR and COF was observed over time up to a transition point, where a tribolayer formed between the mating parts. Higher loads led to the disintegration of the tribolayer, resulting in increased COF and SWR, with adhesion and delamination identified as the primary wear types. The analysis of the worn surfaces using optical microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy revealed features such as cavities, wear debris, cracks, grooves, craters, and pits.