Developing Wear Equation for AA2024 Hybrid Composites Sliding Under Dry and Lubricating Condition

Abstract

This study investigates the wear behavior of AA2024 hybrid composites reinforced with silicon carbide (SiC) and graphite (Gr) particles under both dry and lubricated conditions. Using the stir casting technique, composites with varying reinforcement percentages were fabricated and subjected to wear tests on a pin-on-disk tribometer. Parameters such as load, sliding velocity, temperature, and sliding distance were varied to evaluate their influence on wear performance. The results indicated that increasing the reinforcement percentage improves hardness and wear resistance due to enhanced load distribution and reduced thermal degradation. Under dry conditions, abrasive and adhesive wear mechanisms dominated, with mechanically mixed layers (MMLs) forming at moderate loads, reducing wear. At higher loads and sliding speeds, wear increased due to reinforcement detachment and thermal softening of the matrix. In contrast, lubrication significantly reduced wear rates by forming protective tribo-films that stabilized particle distribution and minimized friction. Scanning electron microscopy (SEM) revealed smoother surfaces and reduced wear debris under lubricated conditions, emphasizing the role of lubrication in mitigating wear. A wear equation was developed to predict wear rates under varying conditions with a strong correlation to experimental data. The findings highlight the potential of SiC and Gr reinforced AA2024 hybrid composites for applications requiring superior wear resistance under diverse operational environments.