Project Description

Degradation of permanent magnets

The durability of magnets used in permanent magnet motor technology is important for the long-term performance of products. The LINX team at Aarhus University studies the degradation of permanent magnets in aqueous media and at elevated temperatures.

Grundfos Holding A/S (Grundfos) has since the nineties been continuously pursuing lower energy consumptions in motors and hydraulics. This has led to the introduction of the permanent magnet rotor. For Grundfos, it is important to know if, how and when their permanent magnets degrade.

The LINX team at Arhus University (AU) investigates how magnetic materials respond to water and elevated temperatures using X-ray diffraction.

Techniques and Methods

In this LINX project, the LINX team at Aarhus University (AU) uses X-ray diffraction to investigate the degradation of permanent magnets used by Grundfos Holding A/S in permanent magnet motor technology. Degradation may be thermal, chemical and/or mechanical in nature. Thermal effects can cause, e.g., particle growth which may alter the magnetic properties, while ingress of water and oxygen can corrode the magnets. Position resolved X-ray diffraction is applied to trace possible chemical degradation products resulting from long-term water exposure. Thermal effects are investigated by in situ X-ray diffraction experiments at elevated temperatures.

Project Information

Participants: Grundfos Holding A/S, Aarhus University.

Start date, end date: October 2018 – June 2019

Title: Degradation of rare earth permanent magnets (FP08.005, Materials at operating and processing conditions)