Engineering transformation pathways in an Al<sub>0.3</sub>CoFeNi complex concentrated alloy leads to excellent strength–ductility combination
Sriswaroop Dasari, Abhinav Jagetia, Vishal Soni, Bharat Gwalani, Stéphane Gorsse, Rajarshi Banerjee
Abstract
Guided by thermodynamic modeling, engineering phase transformation pathways via thermo-mechanical processing, in a complex concentrated alloy/high entropy alloy (HEA) of composition Al0.3CoFeNi, lead to a novel multi-scale microstructure consisting of fine-scale FCC + L12 grains mixed with B2 + BCC grains. The two-step pathway comprises initial decomposition of the parent single-phase FCC to form a fine-grained FCC + B2 microstructure, which further decomposes in the second step into the complex four-phase mixture, exhibiting an excellent combination of tensile yield stress of ∼1490 MPa, ultimate tensile strength of ∼1663 MPa, with a good ductility of ∼12% at room temperature.