title: Experiments and Model for Serration Statistics in Low-Entropy, Medium-Entropy, and High-Entropy Alloys.
abstract: High-entropy alloys (HEAs) are new alloys that contain five or more elements in roughly-equal proportion. We present new experiments and theory on the deformation behavior of HEAs under slow stretching (straining), and observe differences, compared to conventional alloys with fewer elements. For a specific range of temperatures and strain-rates, HEAs deform in a jerky way, with sudden slips that make it difficult to precisely control the deformation. An analytic model explains these slips as avalanches of slipping weak spots and predicts the observed slip statistics, stress-strain curves, and their dependence on temperature, strain-rate, and material composition. The ratio of the weak spots' healing rate to the strain-rate is the main tuning parameter, reminiscent of the Portevin-LeChatellier effect and time-temperature superposition in polymers. Our model predictions agree with the experimental results. The proposed widely-applicable deformation mechanism is useful for deformation control and alloy design.
authors.affiliation: University of Illinois at Urbana-Champaign, Department of Physics, 1110 West Green Street, Urbana, IL 61801, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Carroll
authors.affiliation: National Tsing Hua University, Department of Materials Science and Engineering, Hsinchu, 30013, Taiwan.
authors.forename: Chi
authors.initials: C
authors.lastname: Lee
authors.affiliation: National Tsing Hua University, Department of Materials Science and Engineering, Hsinchu, 30013, Taiwan.
authors.forename: Che-Wei
authors.initials: CW
authors.lastname: Tsai
authors.affiliation: National Tsing Hua University, Department of Materials Science and Engineering, Hsinchu, 30013, Taiwan.
authors.forename: Jien-Wei
authors.initials: JW
authors.lastname: Yeh
authors.affiliation: University of Illinois at Urbana-Champaign, Department of Physics, 1110 West Green Street, Urbana, IL 61801, USA.
authors.forename: James
authors.initials: J
authors.lastname: Antonaglia
authors.affiliation: University of Illinois at Urbana-Champaign, Department of Physics, 1110 West Green Street, Urbana, IL 61801, USA.
authors.forename: Braden A W
authors.initials: BA
authors.lastname: Brinkman
authors.affiliation: University of Illinois at Urbana-Champaign, Department of Physics, 1110 West Green Street, Urbana, IL 61801, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: LeBlanc
authors.affiliation: The University of Tennessee-Knoxville, Department of Materials Science and Engineering, Knoxville, TN 37996, USA.
authors.forename: Xie
authors.initials: X
authors.lastname: Xie
authors.affiliation: The University of Tennessee-Knoxville, Department of Materials Science and Engineering, Knoxville, TN 37996, USA.
authors.forename: Shuying
authors.initials: S
authors.lastname: Chen
authors.affiliation: The University of Tennessee-Knoxville, Department of Materials Science and Engineering, Knoxville, TN 37996, USA.
authors.forename: Peter K
authors.initials: PK
authors.lastname: Liaw
authors.affiliation: University of Illinois at Urbana-Champaign, Department of Physics, 1110 West Green Street, Urbana, IL 61801, USA.
authors.forename: Karin A
authors.initials: KA
authors.lastname: Dahmen