Effect of extrusion process on the stress corrosion cracking resistance of 7N01 aluminum alloy

Abstract

In this work, the effect of extrusion process on the mechanical properties and the stress corrosion cracking (SCC) resistance of 7N01 aluminum alloys were systematically investigated by tensile testing, slow strain rate testing (SSRT), electrochemical experiment, scanning electron microscopy (SEM), electron backscattered diffraction (EBSD), and transmission electron microscope (TEM) observation, respectively. The results showed that with the increase of extrusion temperature, the SCC resistances of the alloys deteriorated, and this tendency was also proved by the electrochemical experiments including polarization curves and EIS results. The Microstructure observation results revealed that recrystallization played an important role on the SCC resistances of the alloys: the new recrystallization grain boundaries with higher grain boundary energy and wider PFZ could magnify the difference of electrochemical property between grain boundary area and the grain interior, thus raising the stress corrosion crack sensitivity of the alloys.

Keywords

• stress corrosion cracking
• extrusion process
• recrystallization
• al-zn-mg alloys