Effect of Sintering Temperature on the Microstructure and Mechanical Properties of a CoCrFeNi High-entropy Alloy
Author of the article:WANG Nan1 , LUO Shifeng1 , YANG Guangyu2 , LI Xiang1 , WANG Yan1 , CHENG Hefa1 , YANG Xinyu1 , ZHANG Jiuxing1
Author's Workplace：1. School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009, China; 2. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China
Key Words：CoCrFeNi high-entropy alloy; sintering temperature; microstructure; mechanical properties
Abstract：
CoCrFeNi high-entropy alloys were fabricated by spark plasma sintering with a sintering pressure of 40 MPa and
sintering time of 10 min at 900, 950, 1 000, 1 050 and 1 100 ℃. The effects of sintering temperature on the microstructure
and mechanical properties of the CoCrFeNi high-entropy alloy were investigated by characterizing the phase,
microstructure, relative density, microhardness and tensile properties. The results show that sintered CoCrFeNi high-entropy
alloys exhibit a single FCC phase at all sintering temperatures. With increasing sintering temperature, the relative density
increases gradually, and the sample is densified completely at 1 050 ℃. The mechanical properties of CoCrFeNi alloys first
increase and then decrease with increasing sintering temperature. The CoCrFeNi high-entropy alloy obtains optimal
mechanical properties at a sintering temperature of 1 050 ℃, with an ultimate tensile strength of 663 MPa, a yield tensile
strength of 383 MPa and an elongation to fracture of 60.7%.
