Abstract Scope |
Phase-specific damage tolerance was investigated for AlCoCrFeNi2.1 high entropy alloy with a lamellar microstructure of L12 and B2 phases. Microcantilever bending technique was utilized with notches milled in each of the two phases as well as at the phase boundary. The L12 phase exhibited superior bending strength, strain hardening, and plastic deformation, while the B2 phase showed limited damage tolerance during bending. The B2 phase showed ~ 30% higher compressive yield strength compared to the L12 phase, as measured by micropillar compression. However, the bending strength measured by notched microcantilever for the L12 phase was ~ 40% higher (1980 MPa) compared to the B2 (1416 MPa). Post-compression fractography of the L12 phase showed signs of ductile failure, including shear lips at the notch, tearing, and activation of numerous slip planes. In contrast, the B2 phase showed quasi-cleavage fracture and decohesion, with microcracks creating high stress-triaxiality. |