摘要
To increase coercivity and thermal stability of sintered Nd–Fe–B magnets for high-temperature applications, a novel terbium sulfide powder is added into（Pr（0.25）Nd（0.75））（30.6）Cu（0.15）Fe（bal）B1（wt.%） basic magnets. The effects of the addition of terbium sulfide on magnetic properties, microstructure, and thermal stability of sintered Nd–Fe–B magnets are investigated.The experimental results show that by adding 3 wt.% Tb2S3, the coercivity of the magnet is remarkably increased by about 54% without a considerable reduction in remanence and maximum energy product. By means of the electron probe microanalyzer（EPMA） technology, it is observed that Tb is mainly present in the outer region of 2：14：1 matrix grains and forms a well-developed Tb-shell phase, resulting in enhancement of HA, which accounts for the coercivity enhancement.Moreover, compared with Tb2S3-free magnets, the reversible temperature coefficients of remanence（α） and coercivity（β） and the irreversible flux loss of magnetic flow（hirr） values of Tb2S3-added magnets are improved, indicating that the thermal stability of the magnets is also effectively improved.
To increase coercivity and thermal stability of sintered Nd–Fe–B magnets for high-temperature applications, a novel terbium sulfide powder is added into（Pr（0.25）Nd（0.75））（30.6）Cu（0.15）Fe（bal）B1（wt.%） basic magnets. The effects of the addition of terbium sulfide on magnetic properties, microstructure, and thermal stability of sintered Nd–Fe–B magnets are investigated.The experimental results show that by adding 3 wt.% Tb2S3, the coercivity of the magnet is remarkably increased by about 54% without a considerable reduction in remanence and maximum energy product. By means of the electron probe microanalyzer（EPMA） technology, it is observed that Tb is mainly present in the outer region of 2：14：1 matrix grains and forms a well-developed Tb-shell phase, resulting in enhancement of HA, which accounts for the coercivity enhancement.Moreover, compared with Tb2S3-free magnets, the reversible temperature coefficients of remanence（α） and coercivity（β） and the irreversible flux loss of magnetic flow（hirr） values of Tb2S3-added magnets are improved, indicating that the thermal stability of the magnets is also effectively improved.
基金
Project supported by the Science Funds from the Ministry of Science and Technology,China(Grant Nos.2014DFB50130 and 2011CB612304)
the National Natural Science Foundation of China(Grant Nos.51172168 and 51072139)
