1 Deformation mechanisms of Al 0.1 CoCrFeNi at elevated temperatures Tengfei Yang a,b *, Zhi Tang a , Xie Xie a , Robert Carroll d , Gongyao Wang a , Yugang Wang b , Karin A. Dahmen d , Peter K. Liaw a , Yanwen Zhang c,a a Department of Materials Science and Engineering, the University of Tennessee, Knoxville, TN 37996, USA b State Key Laboratory of Nuclear Physics and Technology, Center for Applied Physics and Technology, Peking University, Beijing 100871, People’s Republic of China c Materials Science & Technology Division, Oak Ridge National Laboratory, TN 37831-6138, USA d Department of Physics, University of Illinois at Urbana Champaign, 1110 West Green Street, Urbana IL 61801, USA Abstract Deformation mechanisms of a high-entropy alloy with a single face-centered-cubic phase, Al 0.1 CoCrFeNi, at elevated temperatures are studied to explore the high temperature performances of high-entropy alloys. Tensile tests at a strain rate of 10 -4 s -1 are performed at different temperatures ranging from 25 to 700 °C. While both yield strength and ultimate tensile strength decrease with increasing temperature, the maximum elongation to fracture occurred at 500 °C. Transmission electron microscopy characterizations reveal that, at both 25 and 500 °C, most of deformation occurs by dislocation glide on the normal face-centered-cubic slip system, {111}<110>. In contrast, numerous stacking faults are observed at 600 © 2016. This manuscript version is made available under the Elsevier user license http://www.elsevier.com/open-access/userlicense/1.0/