A multidisciplinary approach to study precipitation kinetics and hardening in an Al-4Cu (wt. %) alloy

TL;DR

This paper integrates multiple experimental and computational techniques to comprehensively analyze precipitation kinetics, interfacial energies, and strengthening mechanisms in an Al-4Cu alloy, providing new insights into the complex transformations during aging.

Contribution

It introduces a multidisciplinary methodology combining thermal analysis, dilatometry, electron microscopy, and density functional calculations to study precipitation and hardening in aluminum-copper alloys.

Findings

First data on coherent and semi-coherent { heta}''/Al interfaces.

Detailed characterization of precipitation kinetics during aging.

Insights into the contributions of second phase precipitates to mechanical strength.

Abstract

A multidisciplinary approach is presented to analyse the precipitation process in a model Al-Cu alloy. Although this topic has been extensively studied in the past, most of the investigations are focussed either on transmission electron microscopy or on thermal analysis of the processes. The information obtained from these techniques cannot, however, provide a coherent picture of all the complex transformations that take place during decomposition of supersaturated solid solution. Thermal analysis, high resolution dilatometry, (high resolution) transmission electron microscopy and density functional calculations are combined to study precipitation kinetics, interfacial energies, and the effect of second phase precipitates on the mechanical strength of the alloy. Data on both the coherent and semi-coherent orientations of the {\theta}"/Al interface are reported for the first time. The combination of the different characterization and modelling techniques provides a detailed picture of the precipitation phenomena that take place during aging and of the different contributions to the strength of the alloy. This strategy can be used to analyse and design more complex alloys.