Effect of post-sintering annealing on microstructure and coercivity of Al85Cu15-added Nd-Fe-B sintered magnets
Effect of post-sintering annealing on microstructure and coercivity of Al85Cu15-added Nd-Fe-B sintered magnets
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DOI：
10.1016/j.jmmm.2010.07.031
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发表时间：
2010-11
影响因子：
2.7
通讯作者：
J. Ni;T. Ma;Y. R. Wu;M. Yan
中科院分区：
文献类型：
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作者：
J. Ni;T. Ma;Y. R. Wu;M. Yan
研究了烧结后退火对Al_（85）Cu_（15）添加（Pr，Nd）_（14.8）Fe_（78.7）B_（6.5）烧结磁体显微组织和磁性能的影响。结果表明，添加0.3%和0.6%Al_（85）Cu_（15）的磁体，其最佳退火温度从550°C降低到480°C。最佳退火温度的降低与退火过程中富（Pr，Nd）相中Al-Cu或（Pr，Nd）−Cu液相的析出有关。Al-Cu或（Pr，Nd）−Cu液相的存在有利于溶解（Pr，Nd）2Fe 14 B晶界的不规则性，增加晶界富（Pr，Nd）相的数量，从而优化晶界组织。显微组织的改变有助于消除（Pr，Nd）2Fe 14 B硬磁晶粒间的交换作用，从而提高磁性能。
Effects of post-sintering annealing on the microstructure and coercivity have been investigated for the Al85Cu15-added (Pr, Nd)14.8Fe78.7B6.5sintered magnets. It is found that the optimum annealing temperature at which the coercivityiHcreaches a maximum decreases from 550°C for the magnets added with 0.3% and 0.6% Al85Cu15to 480°C for the magnets added with 0.9% and 1.2% Al85Cu15. The decrease in optimum annealing temperature is related to the precipitation of Al–Cu or (Pr, Nd)−Cu liquid phase among (Pr, Nd)-rich phases during annealing. Existence of Al–Cu or (Pr, Nd)−Cu liquid phase is beneficial to dissolve the irregularities of (Pr, Nd)2Fe14B grain interface and increase the quantities of (Pr, Nd)-rich phases at the grain boundary, thus optimizing the grain boundary microstructure. The modifications of the microstructure are helpful to decouple the exchange interaction between (Pr, Nd)2Fe14B hard magnetic grains, thereby increasing the coercivity.