Reversible deformation-induced martensitic transformation in Al0.6CoCrFeNi high-entropy alloy investigated by in situ synchrotron-based high-energy X-ray diffraction

• Published in: Acta materialia Vol. 128; no. C; pp. 12 - 21
• Main Authors: Ma, Lili, Wang, Lu, Nie, Zhihua, Wang, Fuchi, Xue, Yunfei, Zhou, Jinlian, Cao, Tangqing, Wang, Yandong, Ren, Yang
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 15-04-2017; Elsevier
• Subjects: High-energy X-ray diffraction; High-entropy alloy; Lattice strain; Martensitic transformation; Micro-mechanical behavior; Martensitic transformation; Lattice strain; Micro-mechanical behavior; High-energy X-ray diffraction; High-entropy alloy
• ISSN: 1359-6454; 1873-2453
• DOI: 10.1016/j.actamat.2017.02.014

The micro-mechanical behavior of Al0.6CoCrFeNi high-entropy alloy during tensile deformation was investigated using an in situ synchrotron-based high-energy X-ray diffraction technique. The alloy consisted of face-center-cubic (FCC) and body-center-cubic-based (BCC-based) structure accompanied by a small amount of σ phase. The FCC phase yielded prior to the BCC-based phase during the tensile loading, and the BCC-based phase bore more stress partition during the plastic deformation stage in spite of only ∼23% volume fraction. A reversible deformation-induced martensitic transformation from the BCC-based phase to orthorhombic phase was observed during the plastic deformation stage. The transformation preferentially occurred in the grains with an orientation of B-[001]//loading direction and B-[110]//transverse direction. The study characterized the micro-mechanical behavior of this alloy, and the reversible martensitic transformation is believed to be beneficial to the fracture toughness of such alloys.
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