TY - JOUR
T1 - Temperature-dependent compression behavior of an Al0.5CoCrCuFeNi high-entropy alloy
AU - Xu, X. D.
AU - Chen, S. Y.
AU - Ren, Y.
AU - Hirata, A.
AU - Fujita, T.
AU - Liaw, P. K.
AU - Chen, M. W.
N1 - Funding Information:
This work was sponsored by “WPI Research Center Initiative for Atoms, Molecules and Materials”; MEXT; and National Science Foundation under Contract DMR-1408722 . M.W.C. is supported by Whiting School of Engineering, Johns Hopkins University. P.K.L. and S.Y.C. are grateful for the support of the Department of Energy (DOE) Office of Fossil Energy, National Energy Technology Laboratory (NETL) ( DE-FE-0011194 ) and the National Science Foundation ( DMR-1611180 and 180964 ), with Drs. J. Mullen, V. Cedro, R. Dunst, S. Markovich, G. Shiflet, and D. Farkas as program managers. S.Y.C. and P.K.L. very much appreciate the support from the U.S. Army Office Project ( W911NF-13-1-0438 ) with the program manager, Drs. M. P. Bakas, S. N. Mathaudhu, and D. M. Stepp. S.Y.C. and P.K.L. would like to acknowledge the financial support of the Center for Materials Processing (CMP), at The University of Tennessee, with the director of Dr. Claudia J. Rawn. The authors would like to thank JunWei Qiao for providing samples.
Publisher Copyright:
© 2019
PY - 2019/3
Y1 - 2019/3
N2 - Mechanical response of an Al0.5CoCrCuFeNi high-entropy alloy (HEA) was investigated through uniaxial compression tests, the 0.2% offset yield strength decreases with increasing temperature up to 773 K. However, at temperatures above 773 K, two yield strength hardening regions peaked at 873 K and 1073 K were observed. Microstructure analyses reveal an enhanced L12 ordering with the increase of compression temperatures and the subsequent precipitation of B2 phase at 973 K. Meanwhile, transmission electron microscopy observations of the post-deformation microstructures show that plastic deformation is primarily carried by dislocation at room temperature, and changes to twinning at temperatures higher than 873 K. At deformation temperatures higher than 1073 K, a mixed microstructure of dislocations and deformation twins is observed. These results suggest that the emerging of the yield strength peaks at high temperatures is related to the precipitation of the L12 and B2 intermetallic phases and high-temperature deformation influences the phase separation and phase selection of the HEA.
AB - Mechanical response of an Al0.5CoCrCuFeNi high-entropy alloy (HEA) was investigated through uniaxial compression tests, the 0.2% offset yield strength decreases with increasing temperature up to 773 K. However, at temperatures above 773 K, two yield strength hardening regions peaked at 873 K and 1073 K were observed. Microstructure analyses reveal an enhanced L12 ordering with the increase of compression temperatures and the subsequent precipitation of B2 phase at 973 K. Meanwhile, transmission electron microscopy observations of the post-deformation microstructures show that plastic deformation is primarily carried by dislocation at room temperature, and changes to twinning at temperatures higher than 873 K. At deformation temperatures higher than 1073 K, a mixed microstructure of dislocations and deformation twins is observed. These results suggest that the emerging of the yield strength peaks at high temperatures is related to the precipitation of the L12 and B2 intermetallic phases and high-temperature deformation influences the phase separation and phase selection of the HEA.
KW - Deformation induced precipitation
KW - High temperature deformation
KW - High-entropy alloy
KW - Intermetallic precipitates
KW - Precipitation strengthening
UR - http://www.scopus.com/inward/record.url?scp=85061317043&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85061317043&partnerID=8YFLogxK
U2 - 10.1016/j.mtla.2019.100243
DO - 10.1016/j.mtla.2019.100243
M3 - Article
AN - SCOPUS:85061317043
SN - 2589-1529
VL - 5
JO - Materialia
JF - Materialia
M1 - 100243
ER -