Effect of a plastic deformation on the Guinier-Preston zones growth in Al-5at%Ag alloy

Abstract

The formation of the Guinier-Preston zones in aluminium alloys is closely linked with the excess vacancies. A plastic deformation exerts an influence on the Guinier-Preston zones precipitation. As well as in the non deformed alloy and in the deformed alloy, the growth kinetics obeys to the JMAK law of the growth controlled by the solute atoms diffusion. However, during the GP zones growth, two stages are observed. During the first one, the plastic deformation slows down the Guinier-Preston zones formation and during the second stage, the plastic deformation accelerates their formation. The plastic deformation promotes the formation of the metastable γ’ phase.

Keywords

• precipitation
• diffusion
• dislocations
• vacancies
• hardening