A preliminary investigation of lightweight materials reinforced with high-entropy alloy particulates

In this preliminary investigation, 0.5-kg batches of commercially pure aluminium and magnesium were selected as matrix materials for developing high-entropy alloy particulate (HEAp)-reinforced metal matrix composites. Equiatomic CoCrFeNiTi HEAp with an average particle size of 50 µm was incorporated at 1, 2, and 3 wt.% using a conventional stir-casting process. Reinforcing both matrices with CoCrFeNiTi HEAp particulates yielded substantial gains in mechanical properties under tensile loading. Specifically, the aluminium composite (A-3HEAp) achieved an ultimate tensile strength of 184 MPa (compared to 110 MPa in the base metal, an increase of 67%) and a yield strength of 129 MPa (compared to 40 MPa, an increase of 223%). This strengthening effect was even more pronounced in the magnesium series (M-3HEAp), where the ultimate tensile strength increased from 40 MPa to 124.3 MPa (an increase of 211%), accompanied by a yield strength increase from 20 MPa to 112.24 MPa (an increase of 461%). This study demonstrates the feasibility of stir casting for fabricating HEAp-reinforced aluminium and magnesium-matrix composites, providing a scalable, cost-effective platform for developing next-generation lightweight structural materials.