Investigation of domain wall pinning effect induced by annealing stress in sintered Nd–Fe–B magnet
Investigation of domain wall pinning effect induced by annealing stress in sintered Nd–Fe–B magnet
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DOI：
10.1016/j.jallcom.2015.04.017
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发表时间：
2015-08
影响因子：
6.2
通讯作者：
Fugang Chen;Tieqiao Zhang;Jing Wang;Lanting Zhang;Gaofeng Zhou
中科院分区：
文献类型：
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作者：
Fugang Chen;Tieqiao Zhang;Jing Wang;Lanting Zhang;Gaofeng Zhou
研究了一种工业烧结的NdFeB磁体在不同烧结后退磁条件下的磁化和退磁行为。重点研究了两阶段后烧结退火工艺后的不同冷却速度。在第一阶段快速冷却的磁体的初始磁化曲线中观察到磁化壁钉扎效应，而第二阶段的冷却速度对钉扎效应影响不大。快速冷却引起的退火应力是磁区壁钉扎的根源。在快速冷却条件下，晶界区域观察到应力诱导条纹，晶界附近的累积应力降低了扭转磁畴形核所需的磁场，导致了较低的矫直力。
The magnetization and demagnetization behaviors of a commercial sintered Nd–Fe–B magnet under various post-sintering annealing conditions were investigated. Focus was placed on the various cooling rates after the two-stage post-sintering annealing process. Domain wall pinning effect was observed in the initial magnetization curves in the magnets with rapid cooling rate in the first-stage annealing, and the cooling rate of the second-stage annealing had little effect on the pinning effect. Annealing stress induced by rapid cooling is the origin of domain wall pinning. Stress-induced fringes were observed in the grain boundary region under rapid cooling conditions and the accumulated stress near the grain boundary decreases the magnetic field required to reverse domain nucleation, leading to a relatively low coercivity.