Lightweight Ultra-Strength in AlFeNiTiV Complex Concentrated Alloys via Cu Microalloying-Driven Lattice Coherency...

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.