A Hall–Petch study of the high toughness Cr40Co30Ni30 multi-principal element alloy

Abstract

Abstract Multi-principal element alloys (MPEAs) are an emergent class of metallic materials that displays a huge range of possible properties and applications. CrCoNi MPEAs attract great interest because they show good strength–ductility combinations, especially in Cr-rich non-equiatomic compositions. In this work, the Cr 40 Co 30 Ni 30 MPEA was produced and characterized at different annealing conditions. This alloy displays a great strength–ductility balance, evidenced by the high uniform deformation (55–70%) and high estimated toughness. It also exhibits high strengthening by grain refining, given by the high Hall–Petch slope ( k = 655 MPa/μm −0.5 ). The grain growth kinetics analysis provides estimates that can aid the design and processing of this alloy for future applications. Deformed samples displayed both TWIP and TRIP effects, once mechanical twins and HCP martensitic phase, arranged in nanometric lamellae, are formed during straining, greatly increasing the number of interfaces in the microstructure and providing good mechanical properties in tension. Graphical abstract