Dresden 2020 – scientific programme

The DPG Spring Meeting in Dresden had to be cancelled! Read more ...

Parts | Days | Selection | Search | Updates | Downloads | Help

MA: Fachverband Magnetismus

MA 50: Permanent Magnets

MA 50.5: Talk

Thursday, March 19, 2020, 16:00–16:15, HSZ 101

Influence of cooling conditions and alloy composition on the microstructure of NdFeB alloys for a deformation production route — •Corinna Müller¹, Franziska Staab¹, Fansun Chi², Peter Groche², Enrico Bruder³, Karsten Durst³, Stefan Riegg¹, and Oliver Gutfleisch¹ — ¹Funktionale Materialien, FB Materialwissenschaft, TU Darmstadt — ²Institut für Produktionstechnik und Umformmaschinen, FB Maschinenbau, TU Darmstadt — ³Physikalische Metallkunde, FB Materialwissenschaft, TU Darmstadt

NdFeB permanent magnets play a key role in renewable energy technologies because their use is required for efficient electric machines. The specific microstructure of these magnets is directly connected to their magnetic performance. The classical powder metallurgical production route uses jet milling and sintering to achieve homogeneous grain sizes of a few micrometers. The related processing costs are however rather high and the here introduced use of rotary swaging could be an alternative and cheaper technique, allowing continuous processing. During swaging in this top-down processing approach the grain size of a cast body is reduced by the deformation. In this work, experiments to microstructure optimization of the starting alloy precursor after casting are presented and compared to the classical powder metallurgical processing. The microstructure was manipulated by the casting mold geometries and the addition of different dopants. The aim is to understand the thermodynamic and kinetic properties of the process (cooling conditions, phase formation, size distribution) and derive an adequate starting microstructure for rotary swaging.