Investigation of the effect of aging process on the mechanical properties of AA2024 aluminum alloy

In this thesis study, the effects of aging heat treatment applied to the AA2024 aluminum alloy, which exhibits a precipitation hardening mechanism, on the mechanical properties and microstructure of the material were experimentally investigated. As part of the experimental work, AA2024 specimens were solution treated at 500 °C for 2 hours and subsequently subjected to rapid water quenching. This was followed by artificial aging at 190 °C for 5, 10, and 15 hours, respectively. At the end of each aging duration, Brinell hardness measurements and tensile tests were conducted, and microstructural characterization was performed using Scanning Electron Microscopy (SEM). The obtained results showed that with increasing aging time, both hardness and tensile strength initially increased but started to decrease after 10 hours. Notably, the highest hardness value of 109.77 HB and tensile strength of 310.04 MPa were observed at 10 hours of aging. SEM analyses supported these findings, revealing that the precipitates in the 10-hour aged samples were fine, uniformly distributed, and coherent with the matrix, while in the 15-hour aged samples, the precipitates had grown larger and lost coherence with the matrix, thereby negatively affecting mechanical performance. This study highlights the critical importance of precise aging time control for high-performance applications and presents recommended optimal heat treatment parameters for the AA2024 alloy.