TY - JOUR
T1 - Improved HDDR processing route for production of anisotropic powder from sintered NdFeB type magnets
AU - Sheridan, Richard
AU - Williams, A.J
AU - Harris, Ivor
AU - Walton, A.
PY - 2014/1/1
Y1 - 2014/1/1
N2 - The hydrogenation disproportionation desorption recombination (HDDR) process has been investigated as a possible means of producing bonded magnets from used NdFeB-type sintered magnets with compositions, Nd13.4Dy0.8Al0.7Nb0.3Fe78.5B6.3 and Nd12.5Dy1.8Al0.9Nb0.6Co5.0Fe72.8B6.4 (atomic%). It has been shown that by increasing the processing temperature, an increase in the equilibrium pressure for disproportionation and in the overall reaction time was observed. The magnetic properties of the lower Dy content magnet were affected significantly by the change in processing temperature with a peak in properties observed at 880 °C 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 on magnets with a significantly higher Dy content has shown that simultaneous processing of sintered magnets with varying compositions can be achieved by increasing the hydrogen pressure, however a range of magnetic properties are produced depending on the initial compositions of the samples in the input feed.
AB - The hydrogenation disproportionation desorption recombination (HDDR) process has been investigated as a possible means of producing bonded magnets from used NdFeB-type sintered magnets with compositions, Nd13.4Dy0.8Al0.7Nb0.3Fe78.5B6.3 and Nd12.5Dy1.8Al0.9Nb0.6Co5.0Fe72.8B6.4 (atomic%). It has been shown that by increasing the processing temperature, an increase in the equilibrium pressure for disproportionation and in the overall reaction time was observed. The magnetic properties of the lower Dy content magnet were affected significantly by the change in processing temperature with a peak in properties observed at 880 °C 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 on magnets with a significantly higher Dy content has shown that simultaneous processing of sintered magnets with varying compositions can be achieved by increasing the hydrogen pressure, however a range of magnetic properties are produced depending on the initial compositions of the samples in the input feed.
U2 - 10.1016/j.jmmm.2013.09.042
DO - 10.1016/j.jmmm.2013.09.042
M3 - Article
SN - 0304-8853
VL - 350
SP - 114
EP - 118
JO - Journal of Magnetism and Magnetic Materials
JF - Journal of Magnetism and Magnetic Materials
ER -