Influence of Sliding-Friction Induced Strain Hardening on the Tribological Behavior of Friction Stir Processed AA2219 Alloy

In this work, the viability of Friction Stir Processing (FSP) was explored as a potential method to enhance the tribological properties of aerospace alloy AA2219-T87. The dry sliding wear properties of FSP, and as-received AA2219 alloy in mild and severe wear regimes were studied using a vertical- interaction tribometer by varying contact pressures and sliding speeds. The results show that, FSP samples exhibited an enhanced wear resistance in the severe wear regime and can be attributed to the propensity of FSP aluminium alloy to undergo friction-induced strain hardening in-situ during dry sliding. This recurrent ‘sliding-friction induced strain hardening’ facilitated for an increased hardness towards the sliding-interface, thereby enhancing the wear resistance and this was confirmed through cross sectional nano-indentation studies.