Hybrid HEA–CeO2 reinforced surface composites on Al5083 via friction stir processing

This study investigates the development of hybrid surface composites on Al5083 aluminum alloy using friction stir processing (FSP), addressing the limited understanding of how combined metallic and ceramic reinforcements can simultaneously enhance mechanical, wear, and corrosion behavior in aluminum alloys. To fill this gap, mechanically alloyed FeCuMnNiW high entropy alloy (HEA) powder and nano-sized CeO 2 particles were incorporated as a novel hybrid reinforcement system. Three FSP passes ensured uniform dispersion of the reinforcements within the processed zone. The addition of HEA significantly increased hardness (47%), yield strength (55%), and tensile strength (49%), while CeO 2 markedly improved corrosion resistance, reducing the corrosion current density from 14.03 μA/cm 2 for the base alloy to 0.743 μA/cm 2 for the 100CeO 2 composite (≈95% reduction). Wear testing further revealed lower material loss in the reinforced composites compared with both the base alloy and the alloy processed without reinforcements. The hybrid composite containing 75% HEA and 25% CeO 2 exhibited the most balanced performance, demonstrating a synergistic enhancement of properties. These findings highlight the novelty and effectiveness of combining HEA and CeO 2 particles to create high-performance Al5083 surface composites suitable for demanding industrial applications. • Al5083 surface composites reinforced with HEA and CeO 2 fabricated via Friction Stir Processing. • FSP caused significant microstructural refinement and grain size reduction. • HEA addition enhanced hardness (+47%), yield strength (+55%), and tensile strength (+49%). • CeO 2 reinforcement offered the best corrosion resistance. • The hybrid (75% HEA, 25% CeO 2 ) composite showed optimal strength, wear, and corrosion performance.