Magnetic Properties of Nd–Fe–B Permanent Magnets under Thermal Experimentation

Authors

• Géraldine Houis, University of Nebraska-LincolnFollow

First Advisor

Jeffrey Shield

Date of this Version

12-2019

Document Type

Thesis

Citation

Géraldine Houis, "Magnetic Properties of Nd-Fe-B Permanent Magnets Under Thermal Experimentation", University of Nebraska-Lincoln, 2019

Comments

A thesis Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Mechanical Engineering and Applied Mechanics, Under the Supervision of Professor Jeffrey E. Shield. Lincoln, Nebraska: December, 2019.

Copyright (c) 2019 Géraldine Houis

Abstract

Neodymium-Iron-Boron (Nd-Fe-B) magnets were developed in the 1980s, and since then, they have appeared as a common component in many fields. From the industry to consumers or defense applications, from turbines, computers, cellphones to most audio systems, Nd-Fe-B magnets are present everywhere. But when Nd-Fe-B magnets are applied to the motors of electric vehicles and wind-turbine generators, their temperature rises, therefore Nd-Fe-B-Dy magnets are used. However, while the use of these magnets is common at low temperatures, their properties decrease dramatically with the increase of temperature. In this paper, the Nd-Fe-B-based samples used were prepared by using arc melting, melt spinning, annealing (600-800°C, 10-20min), spark-plasma sintering (700°C, 30-40s), hot deformation, and grain boundary diffusion (Nd₇₀Cu₃₀, Pr-Cu-Al, Nd₆₂Dy₂₀Al₁₈). The objective of this paper is to get a better understanding of the magnetic properties (coercivity, remanence, energy product) of these magnets under different temperatures and with slightly different compositions and processes in order to find a correlation between them.

Advisor: Jeffrey E. Shield