Measurement and modelling of the thermodynamic properties of Ni51Fe36Co13 soft magnetic alloy

摘要

A soft magnetic alloy, Ni51Fe36Co13 is used as the sensor in temperature sensitive magnetic switch circuit of diverse safety rod drive mechanism of advanced fast breeder reactors. In the present work the magnetic and thermodynamic properties of this indigenously developed soft ferromagnetic alloy were measured using variety of experimental techniques. The alloy has a single phase face centered cubic structure from room temperature up to 1273 K with the Curie transition at 898 +/- 1 K. Temperature dependent enthalpy increment, dilatation and thermal diffusivity were measured from 298 to 1273 K and the corresponding values for isobaric heat capacity, coefficient of linear thermal expansion and thermal conductivity were determined. In addition, dynamic elastic moduli and Poisson's ratio were also estimated using impulse excitation technique. In the course of evaluation of thermodynamic properties, contribution due to magnetic ordering was treated separately using the Calphad approach to indicate the magneto-volume and magneto-caloric effect. To understand the low temperature behavior, calculations based on quasi harmonic theory were carried out using measured thermodynamic quantities. Based on the study, it is observed that magnetic ordering has significant effect on the thermodynamic properties of Ni51Fe36Co13 ferromagnetic alloy. (C) 2020 Elsevier B.V. All rights reserved.