Microstructure, Mechanical and Wear Resistance Properties of AlCoCrFeNi2.1-xNi3Al Eutectic High-Entropy Alloy Matrix Composites

AlCoCrFeNi2.1-xNi(3)Al (x = 0, 5.0, 7.5, and 10 wt%, denoted as Ni(3)Al0, Ni(3)Al5.0, Ni(3)Al7.5, and Ni(3)Al10) eutectic high-entropy alloy (EHEA) matrix composites were fabricated by mechanical alloying and spark plasma sintering methods. The effects of Ni3Al content on the microstructures, mechanical and wear properties of AlCoCrFeNi2.1 EHEA were investigated. The results indicate that the AlCoCrFeNi2.1-xNi(3)Al composites present cellular grid morphologies composing of FCC/Ll(2) and B2 phases, and a small amount of Al2O3 and Cr7C3 phases. The addition of Ni3Al significantly enhanced the compressive yield strength, compressive fracture strength, compressive strain and wear properties of the AlCoCrFeNi2.1 composites. In particular, the Ni(3)Al10 composite exhibits excellent comprehensive mechanical properties. The compressive yield strength, compressive fracture strength and compressive strain of the Ni(3)Al10 composite, are 1845 MPa, 2301 MPa and 10.1%, respectively. The friction coefficient, wear width and depth, and mass loss of the Ni(3)Al10 composite were 0.40, 0.9 mm, 20.5 mm, 0.016 g, respectively. Moreover, the wear mechanism of the Ni(3)Al10 composite is major abrasive wear with a small amount of adhesive wear.