Mechanical Behavior and Microstructure Evolution during Superplastic Deformation of the Fine-Grained AlCoCrCuFeNi High Entropy Alloy

Abstract:

Characteristics of mechanical behavior during superplastic flow and associated microstructural evolution in the wrought AlCoCrCuFeNi high-entropy alloy were studied. The alloy had complex microstructure with fine grain/particle size of ≈2.1 μm. 4 different phases with volume fractions from 7% to 46% and different deformation characteristics were found in the alloy. Very high tensile elongations of up to 1240% were observed during deformation at temperatures of 800°C–1000°C and at strain rates of 10^-4 s^-1–10^-1 s^-1 despite presence of pronounced softening stage followed by steady state flow stage. Microstructure of the alloy after tensile testing was studied in detail. Phase transformations were analyzed employing thermodynamic modeling and their role in strain accommodation is discussed.

• Periodical: Materials Science Forum (Volumes 838-839)
• Pages: 302-307
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.838-839.302
• Online since: January 2016
• Authors: Nikita Stepanov*, D.G. Shaysultanov, Gennady A. Salishchev, O.N. Senkov
• Keywords: High Entropy Alloys, Microstructure, Phase Transformations, Superplasticity, THERMOMECHANICAL PROCESSING

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