# Synergistic Effects of Pre-Stretching and Aging Temperature on Precipitation Behavior and Damage Tolerance of an Al-Cu-Li Alloy

## TL;DR

This study shows how pre-stretching and aging temperature together affect the strength and durability of an aluminum alloy.

## Contribution

The paper reveals a synergistic optimization method for enhancing strength and damage tolerance in Al-Cu-Li alloys.

## Key findings

- Pre-stretching refines T1 and θ′ phases, improving fracture toughness and fatigue resistance.
- Higher aging temperatures coarsen T1 and grain boundary precipitates, reducing damage tolerance.
- Combining 3.5~4.5% pre-stretching with 145~155 °C aging optimizes strength and damage tolerance.

## Abstract

This study systematically investigates the synergistic effects of the pre-stretching deformation and aging temperature on the precipitation behavior and mechanical properties of an Al-Cu-Li alloy. The results indicate that increasing the pre-stretching deformation significantly refines and increases the number density of T1 and θ′ phases while optimizing the grain boundary precipitate morphology, thereby enhancing the fracture toughness and fatigue resistance without compromising the high strength. In contrast, elevating the aging temperature promotes the coarsening of the T1 phase, inhibits θ′ precipitation, and coarsens the grain boundary precipitates, leading to a deteriorated damage tolerance. By matching 3.5~4.5% pre-stretching with 145~155 °C aging, a synergistic optimization of ultra-high strength and damage tolerance can be achieved.