An investigation of the strain dependence of dynamic precipitation in an Al-Zn-Mg-Cu alloy

• DOI: 10.1016/j.scriptamat.2017.04.031
• Publication Date: 2017-04-28T14:30:40Z
• Authors: L. Couturier; A. Deschamps; F. De Geuser; F. Fazeli; W.J. Poole
• Keywords: Volume fraction; Strain (injury)

Abstract The use of high strength Al-Zn-Mg-Cu alloys in automotive components is restricted by their low formability. Warm forming in the under-aged state improves formability, but induces a strain-dependent microstructure evolution due to dynamic precipitation. We present a new methodology to quantitatively evaluate the dynamic precipitation strain dependence which is applicable to strain rates relevant to forming. The plastic strain is varied using a tapered tensile sample and the precipitation state is measured in terms of size and volume fraction using spatially resolved small-angle X-ray scattering, showing its evolution during straining is dependent on the imposed strain level and rate.