Synthesis of ultrafine dual-phase structure in CrFeCoNiAl0.6 high entropy alloy via solid-state phase transformation during sub-rapid solidification. (20th June 2022)

• Record Type: Journal Article
• Authors: Chen, Chen; Fan, Yanzhou; Wang, Wei; Zhang, Hang; Hou, Jialiang; Wei, Ran; Zhang, Tao; Wang, Tan; Li, Mo; Guan, Shaokang; Li, Fushan
• Is Part Of: Journal of materials science & technology. Volume 113(2022)
• Page Start: 253
• Page End: 260
• Publication Date: 2022-06-20
• Subjects: High entropy alloy -- Cooling rate -- Orientation -- Mechanical properties -- Phase transition; Metals -- Periodicals; Materials science -- Periodicals; Materials science; Metals; Periodicals; 620.1105
• DOI: 10.1016/j.jmst.2021.09.013
• Languages: English
• ISSNs: 1005-0302

Abstract

Highlights: An ultrafine dual-phase CrFeCoNiAl0.6 HEA was fabricated via different cooling rates. FCC/BCC ratio is influenced by cooling rates. Cooling rate could tune mechanical properties of this HEA in a wide range. Ultrafine structure is caused by solid-state phase transformation during cooling. Abstract: High entropy alloys (HEAs) with superb mechanical properties have been traditionally produced by solidification and subsequent heat treatment. In this paper, we demonstrate a new route via one-step process using sub-rapid cooling. Under proper cooling rates, the CrFeCoNiAl0.6 HEA could form ultrafine FCC+BCC dual-phase structure. By varying cooling rate, we can control the fraction of the BCC phase and refinement of FCC microstructures that have tunable mechanical properties in yield strength and hardness ranging from ∼580 to ∼1460 MPa and ∼260 to ∼550 Hv. We show that the structure-property-processing relation originates from the sideplate microstructures formed during fast cooling that have specific crystallographic orientation relationship between the FCC and BCC phases and chemical segregation. This work provides a new setting for better understanding of the solid-state phase transformation in HEAs under sub-rapid solidification conditions as well as a novel method for development of high-performance HEAs. Graphical Abstract: Graphical Abstract Image, graphical abstract .