High throughput evaluation of the effect of Mg concentration on natural ageing of Al-Cu-Li-(Mg) alloys

TL;DR

This study investigates how varying magnesium levels influence the natural ageing process of Al-Cu-Li alloys, revealing Mg's role in cluster and precipitate formation through advanced characterization techniques.

Contribution

It introduces a high throughput method to analyze Mg effects on natural ageing in Al-Cu-Li alloys using compositionally graded materials and X-ray scattering.

Findings

Mg content affects Cu-rich cluster characteristics

Larger precipitates form above 0.1 at.% Mg

Natural ageing involves formation of Cu-rich clusters

Abstract

The effect of Mg content on the natural ageing of Al-Cu-Li-(Mg) alloys has been investigated on a compositionally graded material made by linear friction welding, allowing to probe Mg contents between 0 and 0.4 at.%. High throughput time-and space-resolved characterization of natural ageing kinetics has been achieved using small-angle X-ray scattering, supplemented by differential scanning calorimetry. Natural ageing results mainly in the formation of Cu-rich clusters whose characteristics strongly depend on the presence of Mg. Larger precipitates of 2 nm size also form to a lesser extent above a Mg concentration of 0.1 at.%.