The hydrogenation disproportionation desorption recombination (HDDR) process has been investigated as a possible means of producing bonded magnets from used NdFeB-type sintered magnets and manufacturing scrap material. It has been shown that increasing the processing temperature increased the equilibrium pressure for disproportionation and overall reaction time. The magnetic properties were affected significantly by the change in processing temperature with a peak in properties observed at 880⁰C producing magnetic powder with a remanence of 1.08 (±0.02) T, a coercivity of 840 (±17) kA m-1, and a maximum energy product of 175 (±2.5) kJ m-3. Further work has shown that simultaneous processing of sintered magnets with varying compositions could be achieved by increasing the hydrogen pressure.
|Title of host publication||Proceedings of the 22nd International Workshop on Rare Earth Permanent Magnets and their Applications|
|Place of Publication||Nagasaki, Japan|
|Number of pages||4|
|Publication status||Published - Sep 2012|