Effect of High-Entropy Alloy Amount on Microstructural and Mechanical Properties of Metal Matrix Composites Fabricated via Friction Stir Processing

Metal matrix composites (MMCs) produced by using high-entropy alloy (HEA) powders as reinforcements exhibit superior mechanical properties. In this study, the microstructure, mechanical properties, wear, and corrosive behavior of Al7075/HEA MMCs produced by friction stir processing (FSP) using HEA powders at various ratios (5% and 10%) are systematically investigated. The effect of FSP and HEA powders leads to a grain size reduction of about 23%. The hardness of the MMC structure shows a significant improvement, increasing by 129% compared to the base material. The tensile strength increases by about 46%. Compared to the base material, MMCs containing 10% HEA have a corrosion resistance about 82% higher. While wear resistance is adversely affected by FSP alone, the addition of HEA powders alleviates this disadvantage. Compared to specimens exposed to FSP alone, HEA reinforcement improves the wear performance. Despite the improvements in strength and hardness, elongation values decrease in MMCs. The findings indicate that HEA-reinforced Al7075 MMCs with an ideal combination of strength, hardness, and corrosion resistance make them promising candidates for structural applications requiring superior mechanical properties.