Investigation of the effect of severe plastic deformation and aging processes on the microstructure, mechanical and tribologicial properties of Al 2024 alloy

In this study, different processes consisting of equal channel angular pressing (ECAP) and aging heat treatments were applied to Al 2024 alloy. In this context, the optimum processes that can be applied to Al 2024 alloy were determined. The new microstructure of the alloy as a result of grain refinement and precipitate formation as well as its mechanical and tribological properties were systematically investigated. Within the scope of the study, it was determined that the ECAP process carried out at a temperature of 200 °C refines the grain size of the alloy to approximately 5 µm. In addition, after ECAP, the strength and hardness values of the alloy increased from 365 MPa and 164 Hv to 540 MPa and 220 Hv, respectively. On the other hand, the ductility value decreased from 16% to 5%. It was determined that the appropriate artificial aging temperature after ECAP was 100 °C and at this temperature, the alloy could maintain its hardness value for 850 hours. Friction and wear tests were carried out in dry environment for all processes. Although the lowest wear resistance was found in the ECAP condition, the wear resistance of the alloy was found to increase with aging treatments. Although the dominant wear mechanism was determined as adhesion on the wear surfaces, abrasion, delamination and oxidation effects were also observed on the surfaces.