The effect of sintering neodymium-ion-boron big size magnets in vacuum has been decided. High remanences and near theoretical densities were achieved with uniform shrinkage and minimal floor deterioration. Post-sintering heat treatments revealed the neodymium-wealthy grain boundary section was misplaced during sintering. It was concluded that this section was essential for prime coercivity development during heat remedy. The worst coercivity improvement response occurred in totally sintered, low preliminary neodymium content material alloys.Magnetic and remanent polarization loops had been performed on dysprosium doped, neodymium-iron-boron sintered magnets. The impact of preliminary utilized subject on the coercivity of discipline and thermally demagnetized samples, together with minor and recoil loops was examined...
Institute: University of Bradford (United Kingdom)
Available from UMI in affiliation with The British Library. Requires signed TDF.The impact of sintering neodymium-ion-boron magnets in vacuum has been decided. High remanences and near theoretical densities had been achieved with uniform shrinkage and minimal floor deterioration. Post-sintering heat remedies revealed the neodymium magnet-rich grain boundary section was misplaced during sintering. It was concluded that this section was essential for top coercivity improvement throughout heat treatment. The worst coercivity improvement response occurred in totally sintered, low initial neodymium content alloys.Magnetic and remanent polarization loops have been performed on dysprosium doped, neodymium-iron-boron sintered magnets. The impact of initial utilized area on the coercivity of subject and thermally demagnetized samples, along with minor and recoil loops was examined. If you beloved this posting and magnetic drum you would like to acquire far more info relating to neodymium magnet guide kindly check out our own web page. Weak pinning fields ($approx$0.Four MAm$sp-1$) were found in thermally demagnetized specimens. A 10-20$mu$m non-contributory surface layer was discovered to exist. The coercivity mechanism was best defined from the outcomes, as nucleation and strong pinning of area partitions at grain boundaries.Magnetic viscosity was examined as a perform of applied area and temperature, for a excessive coercivity (1.24 MAm$sp-1$ at 292 K) and a decrease coercivity (0.84 MAm$sp-1$ at 292 K) magnet. The change in magnetic and remanent polarization upon application of a relentless area, different logarithmically with time, as predicted by principle. The rate of change was discovered to be comparable between the 2, strengthening the supposition that magnetic viscosity is an irreversible process.The irreversible susceptibility and magnetic viscosity were proven to be related to the coercivity distribution of the grains. Thus magnetic viscosity happens predominantly in grains with coercivities near the applied subject.Magnetic viscosity data was launched into theoretical models, and confirmed the lower coercivity magnet to be managed by weak domain wall pinning at all temperatures examined, whilst the excessive coercivity magnet contained robust pinning at 292 K, being replaced by weak pinning with growing temperature.