Effect of boron addition on the solidification sequence and microstructure of AlCoCrFeNi alloys

Author(s)

Ferrari, V ^[1] ; Wolf, W. ^{[2, 3]} ; Zepon, G. ^[1] ; Coury, F. G. ^[4] ; Kaufman, M. J. ^[4] ; Bolfarini, C. ^[1] ; Kiminami, C. S. ^[1] ; Botta, W. J. ^[1]

Affiliation

^[1] Univ Fed Sao Carlos, Dept Mat Engn, Rod Washington Luiz, Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Carlos, Postgrad Program Mat Sci & Engn, Rod Washington Luiz, Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[3] Univ Fed Minas Gerais, Dept Met & Mat Engn, Av Antonio Carlos 6627, BR-31270901 Belo Horizonte, MG - Brazil

^[4] Colorado Sch Mines, Dept Met & Mat Engn, 1500 Illinois St, Golden, CO 80401 - USA

• Document type: Journal article
• Source: Journal of Alloys and Compounds; v. 775, p. 1235-1243, FEB 15 2019.
• Web of Science Citations: 2

Abstract

An in-depth analysis of the effect of boron addition on the microstructure of the equiatomic AlCoCrFeNi High Entropy Alloy (HEA) was performed. Alloys with nominal compositions AlCoCrFeNiB0.1 and AlCoCrFeNi were produced and analyzed by multi-scale characterization techniques, including X-ray diffraction, scanning and transmission electron microscopy coupled with TEM-based orientation mapping technique. CALPHAD simulation was carried out to understand the solidification sequence and the phase stability of the studied alloys. The equiatomic AlCoCrFeNi alloy forms a mixture of an Al-Ni rich B2 phase with a Fe-Cr rich body centered cubic (BCC) phase; small face centered cubic (FCC) islands were also observed. The boron addition leads to the formation of needle-like Cr-rich borides with an ortho rhombic structure. Moreover, this addition changes considerably the solidification sequence in later stages of the solidification process, resulting in a more complex microstructure. (C) 2018 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 13/05987-8 - Processing and characterization of amorphous, metastable and nano-structured metallic alloys
• Grantee: Claudio Shyinti Kiminami
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 17/21114-5 - Study and characterization of phase formation and stability in an AlCoCrFeNiB0.1 high entropy alloy
• Grantee: Vítor Ramos Ferrari
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• FAPESP's process: 16/12601-7 - Effect of the cooling rate on the microstructure of High-Entropy Alloys of the AlxCoFeCrNiBy system
• Grantee: Vítor Ramos Ferrari
• Support Opportunities: Scholarships in Brazil - Scientific Initiation