Fracture toughness and fracture micromechanism in a cast AlCoCrCuFeNi high entropy alloy system

This investigation is aimed to understand crack initiation resistance and mechanism of cracking in a high entropy alloy, Al23Co15Cr23Cu8Fe15Ni15 (at%). The fracture toughness of the alloy consisting of primarily Fe-Cr rich disordered and Al-Ni rich ordered BCC phases is found to be 5.4±0.2 MPa m1/2. Lower magnitude of fracture toughness has been attributed to nanosized microstructural constituents, in which cracking is governed by formation of shear bands, cleavage facets and herringbone type features.