Abstract In the present work, the influence of the heating rate on the precipitation kinetics of an Al–Zn–Mg–Cu alloy (AA7075) and its subsequent effect on mechanical properties was investigated. Microhardness and tensile tests were used to examine the hardening and plastic characteristics of the alloy. Transmission and scanning electron microscopy were used to analyze the alloy’s microstructural development. The Al–Zn–Mg–Cu alloy showed notable alterations in microstructure and mechanical behavior during different aging phases. High ductility was a characteristic of the microstructure upon quenching. A high-volume fraction of fine precipitates is visible in the alloy after it has aged at 140 °C, which is the maximum hardness value. The volume fraction of these fine precipitates was quantitatively estimated to be approximately ~ 8–10%. The minimum hardening is recorded after aging at 350 °C. The radical change in the microstructure of the alloy influences its mechanical behavior, especially in hardening and plasticity. By reducing the heating rate, the yield strength is further increased, and the elongation is almost the same. Moreover, a sufficient nucleation of η ′ can be achieved as the heating rate decreases, and as a result, the improvement in mechanical properties is also very significant.
Khitouni et al. (Thu,) studied this question.