Investigation of microstructural and mechanical behavior on cryogenically treated Aluminium 7075 alloy

¹ Department of Mechanical Engineering, St. Joseph’s College of Engineering, Chennai, Tamilnadu, India.
² Department of Mechanical Engineering, St. Joseph’s Institute of Technology, Chennai, Tamilnadu, India.

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 3 March 2026

Abstract

Aluminium (Al) 7075 alloy has been employed in defense and aerospace applications, as well as aircraft fittings. In this investigation, the Al7075 alloy was treated to cryogenic soaking treatment in the range from 2 to 6 hours, whereas the cryogenic soaking temperature was -196°C, a constant. The specimens were immersed in a liquid nitrogen storage reservoir with a controlled cooling temperature of -196°C. The cryogenically treated specimens are subjected to mechanical behaviour tests such as tensile, compression, impact, and hardness tests. Scanning Electron Microscope (SEM) revealed a comparison of the microstructure of the specimen before and after the experiment. The mechanical property of the Al7075 alloy material was enhanced because of grain enhancement through the cryogenic temperature controlled treatment. The grain refinement was the key factor for new grain boundary development in the boundary region, and this grain boundary development enhances mechanical strength in the Al7075 alloy.