New Developments in NdFeB-Based Permanent Magnets

Zhong Wu Liu

doi:10.4028/www.scientific.net/KEM.510-511.1

Paper Titles

Preface, Committees and Sponsors

New Developments in NdFeB-Based Permanent Magnets
p.1

Computational Model of Phase Transformations in Thermo-Chemical Cathodes Using Kinetic Approach
p.9

Recent Advances in Fatigue Crack Growth
p.15

Viscoelastic Response of HTPB Based Solid Fuel to Horizontal and Vertical Storage Slumping Conditions and it's Affect on Service Life
p.22

High Temperature Oxidation Behaviour of Nickel Based Nanostructured Composite Coatings
p.32

Surface Modification and Characterization of Bulk Amorphous Materials
p.43

Structural, Electrical and Dielectric Properties of Nanocrystalline Mg-Zn Ferrites
p.51

An Inquisitive into the Indirect Measurement and Comparison of the Viscosity of Nanoconfined Polystyrene Nanoparticles
p.58

HomeKey Engineering MaterialsKey Engineering Materials Vols. 510-511New Developments in NdFeB-Based Permanent Magnets

New Developments in NdFeB-Based Permanent Magnets

Abstract:

NdFeB based alloys have been used as permanent magnets for almost thirty years. The recent researches aim at optimizing the composition, microstructure and properties, reducing cost, and developing new processes. The demand for sintered magnet is increasing. Efforts are directed towards improving properties by controlling grain boundary diffusion, minimizing the rare earth (RE) content and also improving production yield. As for bonded magnets, to enhance remanence and energy product, nanocrystalline powders are employed. High thermal stability has been realized by mixing NdFeB with hard ferrite powders. For nanocrystalline and nanocomposite NdFeB based alloys, both compositional modification and microstructural optimization have been carried out. New approaches have also been proposed to prepare NdFeB magnets with idea structure. Surfactant assisted ball milling is a good top-down method to obtain nanosized hard magnetic particles and anisotropic nanoflakes. Synthesis of NdFeB nanoparticles and NdFeB/Fe (Co) nanocomposite powders by bottom-up techniques, such as chemical reduction process and co-precipitation, has been successful very recently. To assemble nanocrystalline NdFeB powders or nanoparticles into bulk magnets, various novel consolidation processes including spark plasma sintering and high velocity press have been employed. Hot deformation can be selected as the process to achieve anisotropy in nanocrystalline magnets.