Ab initio assisted design of quinary dual-phase high-entropy alloys with transformation-induced plasticity. (1st September 2017)

• Record Type: Journal Article
• Authors: Li, Zhiming; Körmann, Fritz; Grabowski, Blazej; Neugebauer, Jörg; Raabe, Dierk
• Is Part Of: Acta materialia. Volume 136(2017)
• Page Start: 262
• Page End: 270
• Publication Date: 2017-09-01
• Subjects: High-entropy alloys -- Ab initio calculation -- Phase transformations -- Dual-phase -- Mechanical properties; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2017.07.023
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: We introduce a new class of high-entropy alloys (HEAs), i.e., quinary (five-component) dual-phase (DP) HEAs revealing transformation-induced plasticity (TRIP), designed by using a quantum mechanically based and experimentally validated approach. Ab initio simulations of thermodynamic phase stabilities of Co20 Cr20 Fe40-x Mn20 Nix (x = 0–20 at. %) HEAs were performed to screen for promising compositions showing the TRIP-DP effect. The theoretical predictions reveal several promising alloys, which have been cast and systematically characterized with respect to their room temperature phase constituents, microstructures, element distributions and compositional homogeneity, tensile properties and deformation mechanisms. The study demonstrates the strength of ab initio calculations to predict the behavior of multi-component HEAs on the macroscopic scale from the atomistic level. As a prototype example a non-equiatomic Co20 Cr20 Fe34 Mn20 Ni6 HEA, selected based on our ab initio simulations, reveals the TRIP-DP effect and hence exhibits higher tensile strength and strain-hardening ability compared to the corresponding equiatomic CoCrFeMnNi alloy. Graphical abstract: