Enhancement of strength-ductility trade-off in a high-entropy alloy through a heterogeneous structure. (15th February 2019)

• Record Type: Journal Article
• Authors: Wu, S.W.; Wang, G.; Wang, Q.; Jia, Y.D.; Yi, J.; Zhai, Q.J.; Liu, J.B.; Sun, B.A.; Chu, H.J.; Shen, J.; Liaw, P.K.; Liu, C.T.; Zhang, T.Y.
• Is Part Of: Acta materialia. Volume 165(2019)
• Page Start: 444
• Page End: 458
• Publication Date: 2019-02-15
• Subjects: High-entropy alloys -- Heterogeneous structure -- Strength-ductility trade-off -- Dislocation -- Twin; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2018.12.012
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: The improvement in strength is usually accompanied by ductility loss in structural materials, which is a long-standing conflict referred as the strength-ductility trade-off. Here we present a heterogeneous-structures-architecting strategy, in which we design bulk high-entropy alloys with the largely-enhanced strength-ductility trade-off, possessing a yield strength of 711 MPa, a tensile strength of 928 MPa, and a uniform elongation of 30.3%. Such an enhancement of the strength-ductility trade-off is due to the microstructure comprised with a combination of the non-recrystallized and recrystallized grains arranged in complex heterogeneous structures with a characteristic dimension spanning from the submicron scale to the coarse-sized scale. The heterogeneous structures in the high-entropy alloy are produced by cold-rolling, followed by intermediate-temperature-annealing. Our results demonstrate that heterogeneous designs can be accomplished effectively by simple thermal treatments, which offer a design strategy towards a new generation of high-strength and high-ductility high-entropy alloys. Graphical abstract: Image 1