Research on the structure of Al2.1Co0.3Cr0.5FeNi2.1 high-entropy alloy at submicro- and nano-scale levels

• Published in: Materials letters 2021-07, Vol.294, p.129717, Article 129717
• Main Authors: Osintsev, K.A., Konovalov, S.V., Glezer, A.M., Gromov, V.E., Ivanov, Yu.F., Panchenko, I.A., Sundeev, R.V.
• Format: Article
• Language: English
• Subjects: 3D printing; Aluminum; Chromium; Cobalt; Dendritic structure; Electron microscopy; Grains; High entropy alloys; High-entropy alloy; Iron; Materials science; Microscopes; Microscopy; Nickel; Optical microscopy; Phase composition; Structure; Wire arc additive manufacturing
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2021.129717

•Al2.1Co0.3Cr0.5FeNi2.1 high entropy alloy was obtained by additive manufacturing.•The microstructure consists of dendrite grains and interdendrite areas.•The key phases detected at the submicro-and nano-levels are Al3Ni and (Ni, Co)3Al4.•Content of Al and Ni atoms are prevalent above other elements in the alloy. The Al2.1Co0.3Cr0.5FeNi2.1 high-entropy alloy was a product of wire arc additive manufacturing. The feeding material was a three-core cable with different element compositions: Al – 99.95%; Cr – 20%, Ni – 80%; Co – 17%, Fe – 54%, Ni – 29%. Optical microscopy techniques were applied to study the microstructure of the produced material, which comprised dendrite grains varying from 4 to 15 µm and interdendritic regions. Scanning electron microscopy demonstrated the dendrite grains were generally made of Al and Ni atoms; the interdendritic regions contained Cr and Fe, whereas Co was distributed quasi-homogenously in the material. Transmission electron microscopy detected main phases to be Al3Ni and (Ni, Co)3Al4. An Al3Ni phase is cubic, and a (Ni, Co)3Al4 phase is spherical. 7 to 10 nm (Ni, Co)3Al4 particles were found along the boundaries of submicron (40–100 nm) Al3Ni phases.