Multiplicity of dislocation pathways in a refractory multiprincipal element alloy.

Autor: Wang F; Materials Department, University of California, Santa Barbara, CA, USA., Balbus GH; Materials Department, University of California, Santa Barbara, CA, USA., Xu S; California NanoSystems Institute, University of California, Santa Barbara, CA, USA., Su Y; Department of Mechanical Engineering, University of California, Santa Barbara, CA, USA., Shin J; Materials Department, University of California, Santa Barbara, CA, USA., Rottmann PF; Department of Chemical and Materials Engineering, University of Kentucky, KY, USA., Knipling KE; Materials Science and Technology Division, U. S. Naval Research Laboratory, Washington, DC, USA., Stinville JC; Materials Department, University of California, Santa Barbara, CA, USA., Mills LH; Materials Department, University of California, Santa Barbara, CA, USA., Senkov ON; Air Force Research Laboratory, Wright-Patterson AFB, OH, USA., Beyerlein IJ; Materials Department, University of California, Santa Barbara, CA, USA.; California NanoSystems Institute, University of California, Santa Barbara, CA, USA.; Department of Mechanical Engineering, University of California, Santa Barbara, CA, USA., Pollock TM; Materials Department, University of California, Santa Barbara, CA, USA., Gianola DS; Materials Department, University of California, Santa Barbara, CA, USA. gianola@ucsb.edu.
Jazyk: angličtina
Zdroj: Science (New York, N.Y.) [Science] 2020 Oct 02; Vol. 370 (6512), pp. 95-101.
DOI: 10.1126/science.aba3722
Abstrakt: Refractory multiprincipal element alloys (MPEAs) are promising materials to meet the demands of aggressive structural applications, yet require fundamentally different avenues for accommodating plastic deformation in the body-centered cubic (bcc) variants of these alloys. We show a desirable combination of homogeneous plastic deformability and strength in the bcc MPEA MoNbTi, enabled by the rugged atomic environment through which dislocations must navigate. Our observations of dislocation motion and atomistic calculations unveil the unexpected dominance of nonscrew character dislocations and numerous slip planes for dislocation glide. This behavior lends credence to theories that explain the exceptional high temperature strength of similar alloys. Our results advance a defect-aware perspective to alloy design strategies for materials capable of performance across the temperature spectrum.
(Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)
Databáze: MEDLINE
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