Investigation of the effect of interrupted aging process on mechanical properties of AA2024 and AA7075 aluminum alloys

Alloying has an essential place in the development of new-generation aluminum alloys. However, all the intended requirements, especially high specific strength (strength/density), cannot be achieved with alloying alone. For this reason, aging heat treatment, which is of great importance for aluminum alloys, is applied. High hardness and strength values can be obtained with the conventional T6 aging process. However, in some applications, values such as ductility and toughness are desired to stay the same with higher strength values. In this respect, high specific strength/toughness optimization of industries such as aviation, automotive, and defense can be achieved with interrupted aging, a new generation heat treatment process developed in recent years. In this thesis study, Conventional T6 heat treatment and new generation T6I4 and T6I6 interrupted aging processes were applied to AA2024 and AA7075 aluminum alloys with different parameters, and their effects on the mechanical and morphological properties of the alloys were investigated. After the aging processes were carried out in the determined heat treatment parameters, tensile, bending, wear tests, hardness and surface roughness measurements were applied to the samples. SEM, EDS, XRD and DSC analyses were performed to characterize the relationship between mechanical properties and microstructure. As a result of the study, it was determined that the new generation interrupted aging process gave the alloys remarkably high specific strength and formability (ductility) properties compared to the conventional T6 heat treatment.