High Entropy alloys based on Fe, Co and Ni: Production and Study of Magnetic Properties.

• Grant number: 17/26386-3
• Support Opportunities: Regular Research Grants
• Start date: August 01, 2018
• End date: October 31, 2020
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Cristina Bormio Nunes
• Grantee: Cristina Bormio Nunes
• Host Institution: Escola de Engenharia de Lorena (EEL). Universidade de São Paulo (USP). Lorena , SP, Brazil

Abstract

Some of the high entropy alloys (HEA) based on Fe, Co and Ni have been studied in the literature in the last 7 years. It has been found that these alloys are magnetically smooth and ideally monophasic. However, no magnetostriction has been studied so far. Magnetostriction is an important property to be studied in magnetic materials because it is directly linked to the application of these materials. Interesting applications of soft magnetic materials focusing on magnetostriction are: electric machines that demand low magnetostriction for noise reduction and sensors and actuators that demand high magnetostrictions.In the present work we intend to study the magnetostrictive properties of some alloys already studied in the literature that presented the best compromise of the combination of mechanical properties and saturation magnetization. Based on literature results, the best alloys to study magnetostriction would be FeCoNi (AlSi)0.80, FeCoNi (MnAl)0.25, FeCoNi(CuAl)0.8. In terms of application, both high magnetostrictions and very low magnetostrictions would be interesting depending on the type of application desired.The aim of this work is also to study HEA alloys with FeCoNi(XY)z composition with z <1, so that there is no severe degradation of the magnetic properties. In order to restrict the possible variety of alloys we choose X and Y, for a finite interval of z.One of the natural elements to be introduced in high entropy magnetic alloys is X = Ga, since it is well known that the addition of Ga to Fe causes an increase in Fe magnetostriction by an order of magnitude. Moreover, Ga added to Ni and Co can form a Heussler type NiCoGa alloy that has high values of magnetostriction and magnetic memory. In addition, Ga has good solubility in Fe, Ni and Co. We choose for our studies Y = Cu, ie, the FeCoNi(GaCu)z alloy will be studied in the interval of 0.35 £z £ 0.75, £because following high entropy criteria, adequate enthalpy to avoid the formation of secondary phases and difference of atomic radii lower than 5.5%, these alloys are more likely to be monophasic, a solid solution. This condition is interesting for the soft magnetic properties of materials. (AU)

Scientific publications

(4)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

CARDOSO, FABIO MARTINS; BORMIO-NUNES, CRISTINA. Original Fe-Co-Ni-Ga-Nb Multicomponent Alloy with Soft Magnetic Properties. ADVANCED ENGINEERING MATERIALS, FEB 2021. (17/26386-3)

FULOP, G. O.; BORMIO-NUNES, C.. Production of Fe-6.9 wt%Ti alloy sheets for application in electric machines: Physical properties characterization. Journal of Magnetism and Magnetic Materials, v. 539, DEC 1 2021. (17/26386-3, 18/14939-0)

CARDOSO, FABIO MARTINS; BORMIO-NUNES, CRISTINA. Original Fe-Co-Ni-Ga-Nb Multicomponent Alloy with Soft Magnetic Properties. ADVANCED ENGINEERING MATERIALS, v. 23, n. 5, MAY 2021. (17/26386-3)

BORMIO-NUNES, CRISTINA; CARDOSO, FABIO MARTINS; TEIXEIRA, RODOLFO DA SILVA; BASTOS, JHONATAN FEITOZA. Understanding of the duplex high entropy of FeCoNiCuAl alloys magnetic properties dependence on the CuAl amount and annealing temperature. Journal of Alloys and Compounds, v. 923, p. 8-pg., 2022-07-27. (17/26386-3)