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Title: Plasticity performance of Al 0.5 CoCrCuFeNi high-entropy alloys under nanoindentation

Abstract

The statistical and dynamic behaviors of the displacement-load curves of a high-entropy alloy, Al0.5 CoCrCuFeNi, were analyzed for the nanoindentation performed at two temperatures. Critical behavior of serrations at room temperature and chaotic flows at 200 °C were detected. These results are attributed to the interaction among a large number of slip bands. For the nanoindentation at room temperature, recurrent partial events between slip bands introduce a hierarchy of length scales, leading to a critical state. For the nanoindentation at 200 °C, there is no spatial interference between two slip bands, which is corresponding to the evolution of separated trajectory of chaotic behavior

Authors:
; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
National Natural Science Foundation of China (NNSFC); USDOE Office of Fossil Energy (FE); National Energy Technology Laboratory (NETL); USDOE Office of Science - Office of Basic Energy Sciences - Scientific User Facilities Division
OSTI Identifier:
1377894
DOE Contract Number:
AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: International Journal of Iron and Steel Research; Journal Volume: 24; Journal Issue: 4
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; chaotic behavior; critical behavior; high-entropy alloys; nanoindentation

Citation Formats

Yu, Li-ping, Chen, Shu-ying, Ren, Jing-li, Ren, Yang, Yang, Fu-qian, Dahmen, Karin A., and Liaw, Peter K. Plasticity performance of Al 0.5 CoCrCuFeNi high-entropy alloys under nanoindentation. United States: N. p., 2017. Web. doi:10.1016/S1006-706X(17)30058-4.
Yu, Li-ping, Chen, Shu-ying, Ren, Jing-li, Ren, Yang, Yang, Fu-qian, Dahmen, Karin A., & Liaw, Peter K. Plasticity performance of Al 0.5 CoCrCuFeNi high-entropy alloys under nanoindentation. United States. doi:10.1016/S1006-706X(17)30058-4.
Yu, Li-ping, Chen, Shu-ying, Ren, Jing-li, Ren, Yang, Yang, Fu-qian, Dahmen, Karin A., and Liaw, Peter K. Sat . "Plasticity performance of Al 0.5 CoCrCuFeNi high-entropy alloys under nanoindentation". United States. doi:10.1016/S1006-706X(17)30058-4.
@article{osti_1377894,
title = {Plasticity performance of Al 0.5 CoCrCuFeNi high-entropy alloys under nanoindentation},
author = {Yu, Li-ping and Chen, Shu-ying and Ren, Jing-li and Ren, Yang and Yang, Fu-qian and Dahmen, Karin A. and Liaw, Peter K.},
abstractNote = {The statistical and dynamic behaviors of the displacement-load curves of a high-entropy alloy, Al0.5 CoCrCuFeNi, were analyzed for the nanoindentation performed at two temperatures. Critical behavior of serrations at room temperature and chaotic flows at 200 °C were detected. These results are attributed to the interaction among a large number of slip bands. For the nanoindentation at room temperature, recurrent partial events between slip bands introduce a hierarchy of length scales, leading to a critical state. For the nanoindentation at 200 °C, there is no spatial interference between two slip bands, which is corresponding to the evolution of separated trajectory of chaotic behavior},
doi = {10.1016/S1006-706X(17)30058-4},
journal = {International Journal of Iron and Steel Research},
number = 4,
volume = 24,
place = {United States},
year = {Sat Apr 01 00:00:00 EDT 2017},
month = {Sat Apr 01 00:00:00 EDT 2017}
}
  • Compression behavior of the Al 0.5CoCrCuFeNi high-entropy alloy (HEA) was studied at different temperatures from 673 K to 873 K at a low strain rate of 5 x 10 –5/s to investigate the temperature effect on the mechanical properties and serration behavior. The face-centered-cubic (fcc) structure is confirmed at the lower temperature of 673 K and 773 K, and a structure of mixed fcc and body-centered cubic (bcc) is identified at a higher temperature of 873 K after compression tests using high-energy synchrotron x-ray diffraction. As a result, by comparing the stress–strain curves at different temperatures, two opposite directions ofmore » serrations types were found, named upward serrations appearing at 673 K and 773 K and downward serrations at 873 K, which may be due to dynamic strain aging.« less
  • Compression behavior of the Al 0.5CoCrCuFeNi high-entropy alloy (HEA) was studied at different temperatures from 673 K to 873 K at a low strain rate of 5 x 10 –5/s to investigate the temperature effect on the mechanical properties and serration behavior. The face-centered-cubic (fcc) structure is confirmed at the lower temperature of 673 K and 773 K, and a structure of mixed fcc and body-centered cubic (bcc) is identified at a higher temperature of 873 K after compression tests using high-energy synchrotron x-ray diffraction. As a result, by comparing the stress–strain curves at different temperatures, two opposite directions ofmore » serrations types were found, named upward serrations appearing at 673 K and 773 K and downward serrations at 873 K, which may be due to dynamic strain aging.« less
  • In present study, structure and mechanical properties of the Al{sub x}CrNbTiVZr (x = 0; 0.25; 0.5; 1) high-entropy alloys after arc melting and annealing at 1200 °C for 24 h are investigated. The CrNbTiVZr alloy is composed of body centered cubic (bcc) and C15 (face centered cubic) Laves phases while the Al{sub x}CrNbTiVZr (x = 0.25; 0.5; 1) alloys consist of bcc and two C14 (hexagonal close packed) Laves phases with different chemical compositions. Thermodynamic modeling predicts existence of two phases – bcc and C15 Laves phase and broadening of single bcc phase field due to Al addition. The densitymore » of the alloys decreases with the increase of Al content. The alloys are found to be extremely brittle at room temperature and 600 °C. The alloys have high strength at temperatures of 800–1000 °C. For example, yield strength at 800 °C increases from 440 MPa for the CrNbTiVZr alloy to 1250 MPa for the AlCrNbTiVZr alloy. The experimental phase composition of the Al{sub x}CrNbTiVZr alloys is compared with predicted equilibrium phases and the factors governing the transformation of C15 to C14 Laves phases due to Al addition to the CrNbTiVZr alloy analyzed. Specific properties of the alloys are compared with other high-entropy alloys and commercial Ni-based superalloys. - Highlights: •Al{sub x}CrNbTiVZr (x = 0; 0.25; 0.5; 1) alloys are arc melted and annealed at 1200 °C. •The CrNbTiVZr alloy has bcc and C15 Laves phases. •The Al-containing alloys are composed of bcc and two C14 Laves phases. •The alloys demonstrate high specific strength at temperatures of 800 °C and 1000 °C. •The strength of the alloys increases in proportion with increase of Al content.« less