Deformation twins and interface characteristics of nano-Al2O3 reinforced Al0.4FeCrCo1.5NiTi0.3 high entropy alloy composites

A non-equiatomic Al0.4FeCrCo1.5NiTi0.3 high entropy alloy reinforced by nano-Al2O3 particles was produced by mechanical alloying (MA) and powder metallurgy. Alloying behavior, deformation twins and interface characteristics were investigated. During MA, the formation of a supersaturated solid solution with a single face-centered cubic (fcc) structure occurred. Moreover, deformation twinning only occurred in the fcc phase, which is confirmed by the selected area electron diffraction (SAED) pattern. The bulk high entropy alloy composites (HEACs) show excellent compressive properties. Yield stress, fracture strength, compression ratio and Vickers hardness of Al2O3p-reinforced Al0.4FeCrCo1.5NiTi0.3 HEACs is as high as 2.05 ± 0.01 GPa, 2.14 ± 0.01 GPa, 13.98 ± 0.25% and 654 ± 12Hv, respectively. A distinct characteristic of serrated yielding was presented during the later stages of the stress-strain curve.