Magnetomechanical behavior of Fe-35%Co alloys (% in mass) with addition of 0.5 and 0.7% of Cr

• Grant number: 22/15322-2
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: April 01, 2023
• End date: June 30, 2023
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Cristina Bormio Nunes
• Grantee: Iris Braga Silva
• Supervisor: Olivier Hubert
• Host Institution: Escola de Engenharia de Lorena (EEL). Universidade de São Paulo (USP). Lorena , SP, Brazil
• Institution abroad: Université Paris-Saclay, France
• Associated to the scholarship: 22/08992-1 - Obtaining Fe-35%Co alloys (% in mass) with Cr addition: survey of magnetic properties, BP.IC

Abstract

In the Project (FAPESP 2021/06350-0), to which student Iris Braga's scientific initiation project is inserted, the study of the addition of Cr to improve the mechanical property (deformability) of the binary alloy is followed by the study of the addition of Ti to the Fe-35%Co+Cr alloy, and this addition of Ti aims to increase magnetic permeability and decrease magnetostriction. Specifically, in the ongoing Scientific Initiation Project of the candidate Iris Braga Silva, we study the modification of the Fe-35%Co alloy, by adding Cr, without adding Ti. The first idea is to study separately the addition of Cr, before the addition of Ti, to systematically determine how each of the additions modifies the magnetic and deformation properties of the Fe-35%Co alloy. The addition of Cr alone is not expected to result in an alloy with small magnetostriction values, desired for application in motors and generators, since the amounts of Cr are less than 1% and are not expected to cause major changes in this property. The magnetostriction of the 35% Cr alloy is lambdaS 80 x 10-6, comparable to the magnetostriction of Fe-Ga alloys, known for their excellent magnetomechanical properties. Therefore, the Fe-35%Co alloy with the addition of Cr could be suitable for applications in sensors and actuators, which require the determination of piezomagnetic properties. In particular the coefficient d33* = dlambda/dH related to the use of the material in actuators, as the magnetostriction of the material being high, could result in high values of d33*.This characterization is complementary to the Scientific Initiation work in progress, and the same material produced for the characterization of the magnetic properties and the microstructure will be used for the determination of the piezomagnetic coefficients. This characterization proposed here is pertinent and unprecedented, as the material has the potential to be used in devices such as force sensors or actuators, in addition to the fact that good mechanical formability is also suitable for this type of application. Moreover, these data were never collected, as we did not find anything in the literature on this subject in these alloys. The objectives of the project are to carry out measurements of:1) Magnetic induction (B) for fixed field (H) and varying applied tension and compression values (sigma).2)Longitudinal magnetostriction (lambda long) for fixed applied tension values and varying applied field values (hysteretic and anhysteretic measurements).3) Magnetic induction (B) for fixed values of applied tension and varying values of applied field H (hysteretic and anhysteretic measurements).4) Longitudinal magnetostriction (lambdalong) for fixed field (H) and varying values of applied tension and compression (Sigma). (AU)