• Burkhardt, Carlo
• Weber, O.
• Imgrund, P.
• Kukla, C.
• Pischang, K.
• Harris, Ivor
• Schlauf, T.
• Gonzalez-Gutierrez, J.
• Degri, Malik
• Pickering, Lydia
• Walton, Allan

Abstract

conventional press and sintering approach. However, difficult process ability, due to the high affinity of the powder to oxygen and carbon pickup, remains problematic in terms of obtaining sufficient remanence and coercivity. In this talk, a new approach to MIM NdFeB magnets is presented. The REProMag (Resource Efficient Production of Magnets) processing route is based on the use of powder obtained from recycling of used rare earth magnets by the hydrogen decrepitation (HD) process. A proprietary binder system has been developed for producing a mouldable MIM feedstock, having a chemical composition optimised for the processing of the highly reactive magnetic powder. First prototypes were processed in modified injection mould equipment with magnetically aligned tooling in order to achieve anisotropic green parts that were consequently debinded and sintered under tailored conditions. An overview of the project, including the processing steps and their challenges, the influence of debinding and sintering conditions on interstitial contents and magnetic properties of isotropic and anisotropic sintered MIM parts are presented and discussed. Special attention is given to temperature control, gas pressure conditions and atmospheres during thermal debinding and sintering.

Topics

• impedance spectroscopy
• Carbon
• Oxygen
• reactive
• anisotropic
• Hydrogen
• chemical composition
• isotropic
• interstitial
• sintering
• coercivity
• aligned