Microstructure and Mechanical Properties of AlCoCrFeNi High-Entropy Alloy-Reinforced Ti-Al Metallic-Intermetallic Composites

In this study, a novel high-entropy alloy-reinforced Ti-Al metallic-intermetallic laminated (HEA-MIL) composite was fabricated using vacuum hot pressing sintering. The microstructure characteristics of the HEA-MIL composite interface were examined through X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and electron backscattered diffraction. The analysis revealed the presence of Al 3 Ti, a newly formed phase in the HEA-MIL composite, resulting from the Ti-Al reaction and forming a homogeneous intermetallic compound layer. Furthermore, the HEA layer exhibited a body-centered cubic structure with a uniform stress distribution. Additionally, the mechanical properties of HEA-MIL composites were evaluated through compression tests conducted at quasi-static strain rates. The results revealed that the average compressive strengths of the HEA-MIL composite were 1359.61 MPa (load perpendicular to layers) and 1258.47 MPa (load parallel to layers), with corresponding failure strains of 41.53% and 17.84%, respectively. Fracture analysis demonstrated a mixed fracture mechanism, with both ductile and brittle fractures observed in both perpendicular and parallel directions.