# Lightweight Ultra‐Strength in AlFeNiTiV Complex Concentrated Alloys via Cu Microalloying‐Driven Lattice Coherency Tuning

## TL;DR

A lightweight, high-strength alloy is developed using Cu microalloying to improve performance at high temperatures.

## Contribution

A new Cu microalloying strategy is introduced to achieve ultra-strength and stability in lightweight alloys.

## Key findings

- The alloy achieves ultra-high compressive strength over 3.3 GPa with a density of 6.83 g/cm³.
- It maintains 1311.6 MPa yield strength at 600°C due to low lattice misfit and stable L21 structure.

## Abstract

Next‐generation high‐performance structural materials are required for lightweight design strategies and advanced energy applications. In this work, a custom AlFeNiTiV complex concentrated alloy (CCA) with a combination of ultra‐high compressive strength, over 3.3 GPa, and lightweight, 6.83 g cm−3, is developed via Cu microalloying‐driven lattice coherency tuning. The strengthening of the CCA is based on minimal lattice mismatch to achieve maximum coherency strengthening. Maximum precipitation dispersion and alleviating stress concentration at the interface allow the alloy to maintain a macro compressive strain of 11.8%. Meanwhile, it can still maintain excellent yield strength at 600 °C for the low lattice misfit, extremely stable L21 structure, achieving 1311.6 MPa. These findings provide insights into developing lightweight, high‐temperature CCAs through a phase interface modulation strategy.

This study develops a lightweight AlFeNiTiV complex concentrated alloy (density: 6.83 g cm−
3) through Cu microalloying and lattice coherency tuning. The alloy exhibits ultrahigh compressive strength exceeding 3.3 GPa, 11.8% strain, and retains a yield strength of 1311.6 MPa at 600 °C, demonstrating a phase interface strategy for high‐temperature structural materials.