Study of Aging Heat Treatment Parameters for 7050 and 7075 Aluminum Alloys

Abstract Among the different commercially used Aluminum (Al) alloys, the 7000 series offers some of the highest mechanical properties making them the material of choice for several critical engineering applications. These Al alloys often required to undergo a heat treatment (HT) process to enhance their mechanical and metallurgical properties to the desired levels. Currently, there is a growing need to find the optimal operational parameters for the HT process of Al 7000 series alloys. The operators have to resort to a start/stop approach, while intermittently evaluating and testing the mechanical properties until the desired level is reached. Among the various steps, aging is the final and often the longest step in the HT process. Consequently, the age soak time parameter needs to be narrowed to the smallest possible operating range for industrial applications. This study aims to experimentally optimize the age soak time of Al 7000 series alloys (7050-T74 and 7075-T73) by measuring its hardness, electrical conductivity (EC), fatigue properties. The study found that the optimal age soak times for 7050-T74 and 7075-T73 Al alloys are between 24–27 hours and 22–24 hours, respectively. The results of the study are subsequently confirmed using the grain flow and grain direction analysis. The results of this study are crucial in extending the applications of Al 7000 series alloys in several critical engineering industries.