CoCrFeMnNi high entropy alloy matrix nanocomposite with addition of Al2O3

High Entropy Alloy Matrix nano-Composite (HEAMnC) based on CoCrFeMnNi with 5% additions of α-Al2O3 nano-particles was produced by mechanical alloying and consolidation in Hot Isostatic Press (HIP). Its microstructure consisted of spherical grains with average size 30-150 nm, among which 5-35 nm nano-particles of Al2O3 were identified. X-ray analysis and transmission electron microscopy studies with micro-analysis confirmed predominant presence of face-centered cubic solid solution with alpha aluminum oxide and small amount of M23C6 carbides. In comparison with CoCrFeMnNi HEA without additions, composite hardness increased up to 545 ± 13 HV, while yield strength grew from 1180 MPa to 1600 MPa, accompanied by decrease in plasticity and compressive strength.