Effect of deep cryogenic treatment on the microstructure and mechanical properties of Al–Cu–Mg–Ag alloy

Abstract

Effect of deep cryogenic treatment (DCT) on the aging behavior and tensile properties of Al–Cu–Mg–Ag alloy was investigated. Results show that DCT of Al–Cu–Mg–Ag alloy produces plastic deformation of about 0.2% and high-density dislocations in the α-Al matrix. These dislocations cut second-phase particles in under-aged Al–Cu–Mg–Ag alloy, resulting in a decrease in the size of Ω precipitates and an increase in the number density, thereby weakening the adverse effects of DCT on the tensile properties of the alloy.

Keywords

• Al–Cu–Mg–Ag alloy
• Deep cryogenic treatment
• Ω phase
• Dislocation