Microstructure evolution of recycled 7075 aluminum alloy and its mechanical and corrosion properties.

This paper takes the recycled 7075 aluminum alloy as the object to study its smelting, extrusion and heat treatment processes. The composition, microstructure, mechanical properties and corrosion properties of recycled 7075 aluminum alloys were characterized by spectrometer, optical metallographic microscope, universal tensile testing machine, scanning electron microscope (SEM) and transmission electron microscopy (TEM). The results showed that the composition distribution of recycled 7075 aluminum alloy ingots was more uniform and the microstructure was more optimized. The tensile strength, yield strength and elongation of recycled 7075 aluminum alloy plates were higher than American Society of Testing Materials (ASTM) standard. The recycled 7075-T6 aluminum alloy plates had good corrosion resistance to salt spray. This paper aims to provide guidance for the smelting, extrusion and heat treatment processes of scrap aircraft aluminum alloy regeneration process, and to lay the foundation of the recovery and reutilization of scrap aircraft aluminum alloys. • We obtain the recycled 7075 aluminum alloy using scrap aircraft aluminum alloys. • A method is proposed to prepare the recycled 7075 aluminum alloy ingot. • The level-maintained reuse of scrap aircraft aluminum alloys is realized. • The extruded plates are obtained with one-step extrusion. • The mechanical properties of the extruded plates are better than ASTM standard. [ABSTRACT FROM AUTHOR]