title: A fracture-resistant high-entropy alloy for cryogenic applications.
abstract: High-entropy alloys are equiatomic, multi-element systems that can crystallize as a single phase, despite containing multiple elements with different crystal structures. A rationale for this is that the configurational entropy contribution to the total free energy in alloys with five or more major elements may stabilize the solid-solution state relative to multiphase microstructures. We examined a five-element high-entropy alloy, CrMnFeCoNi, which forms a single-phase face-centered cubic solid solution, and found it to have exceptional damage tolerance with tensile strengths above 1 GPa and fracture toughness values exceeding 200 MPa·m(1/2). Furthermore, its mechanical properties actually improve at cryogenic temperatures; we attribute this to a transition from planar-slip dislocation activity at room temperature to deformation by mechanical nanotwinning with decreasing temperature, which results in continuous steady strain hardening.
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
authors.forename: Bernd
authors.initials: B
authors.lastname: Gludovatz
authors.affiliation: Department of Materials Physics, Montanuniversität Leoben and Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Leoben 8700, Austria.
authors.forename: Anton
authors.initials: A
authors.lastname: Hohenwarter
authors.affiliation: Materials Sciences and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
authors.forename: Dhiraj
authors.initials: D
authors.lastname: Catoor
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
authors.forename: Edwin H
authors.initials: EH
authors.lastname: Chang
authors.affiliation: Materials Sciences and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA. Materials Sciences and Engineering Department, University of Tennessee, Knoxville, TN 37996, USA. georgeep@ornl.gov roritchie@lbl.gov.
authors.forename: Easo P
authors.initials: EP
authors.lastname: George
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. Department of Materials Science and Engineering, University of California, Berkeley, CA 94720, USA. georgeep@ornl.gov roritchie@lbl.gov.
authors.forename: Robert O
authors.initials: RO
authors.lastname: Ritchie