Hot Deformation behavior of CoCrFeMnNi FCC High Entropy Alloy

Eleti, R R and Bhattacharjee, T and Zhao, L and Bhattacharjee, Pinaki Prasad and Tsuji, N (2017) Hot Deformation behavior of CoCrFeMnNi FCC High Entropy Alloy. Materials Chemistry and Physics. ISSN 0254-0584 (In Press)

Full text not available from this repository. (Request a copy)

Abstract

Hot deformation behavior of an equiatomic CoCrFeMnNi high entropy alloy was investigated. Hot compression tests were carried out at various temperatures ranging from 800°C to 1000°C at different strain rates from 0.001s-1 to 1s-1. Stress-strain curves indicated softening due to dynamic recrystallization (DRX) under most conditions. Flow stress analysis was carried out by using Arrhenius type hyperbolic-sine relationship, and a linear dependence of flow stress on Zener-Hollomon parameter (Z) was found. Based on the flow stress analysis, a constitutive equation was formulated for describing interdependency between deformation temperature, strain rate, flow stress and strain. The estimated apparent activation energy (Q) ∼350 kJmol-1 for the hot deformation was approximately similar to the activation energy for diffusion of the slowest diffusing element Ni in this alloy. Microstructural observations were carried out by electron backscatter diffraction (EBSD). The EBSD analysis indicated that the DRX grains nucleated along initial grain boundaries resulting in necklace like structures. The fraction and size of DRX grains showed a strong dependence on Z. Textures of deformed and DRX grains were found to be similar to each other, but rather weak. This feature could be attributed to the nucleation of dynamic recrystallization without any preferential orientation selection.

[error in script]

IITH Creators:

IITH Creators	ORCiD
Bhattacharjee, Pinaki Prasad	http://orcid.org/0000-0002-6422-2601

Item Type:

Article

Additional Information:

The authors sincerely thank Mr. Satheesh of DMRL, Hyderabad for providing starting materials used in the present study. The present study was financially supported by the DST, India (Grant No.SB-S3-ME-47-2013) and the Elements Strategy Initiative for Structural Materials (ESISM) through the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. The first author (R.R.E.) is supported by the JICA (Japan International Cooperation Agency) FRIENDSHIP scholarship. The supports are gratefully appreciated.

Uncontrolled Keywords:

high entropy alloy (HEA); hot deformation; Zener- Hollomon parameter (Z); dynamic recrystallization (DRX); kernel average misorientation (KAM)

Subjects:

Materials Engineering > Materials engineering

Divisions:

Department of Material Science Engineering

Depositing User:

Team Library

Date Deposited:

05 Jul 2017 06:51

Last Modified:

31 Aug 2017 06:42