交換耦合作用與顯微組織
(北京科技大學(xué) 新金屬材料國(guó)家重點(diǎn)實(shí)驗(yàn)室，北京 100083)
摘 要: 采用熔體快淬及晶化退火工藝制備了含鈮單相納米晶Nd12.3Fe79.2Nb2.5B6合金，研究添加Nb對(duì)單相Nd2Fe14B納米晶合金的磁性能、交換耦合和微觀結(jié)構(gòu)的影響規(guī)律。結(jié)果表明：Nb的添加提高了合金的非晶熱穩(wěn)定性，使得合金最佳晶化溫度升高；合金晶化退火后，Nb可使晶粒尺寸分布均勻，并得到單一Nd2Fe14B相；晶粒邊界比較完整，存在共格、半共格或大角度晶界，但沒(méi)有觀察到晶界相。上述結(jié)構(gòu)可有效提高合金的磁性能，增強(qiáng)交換耦合作用。通過(guò)對(duì)Nd12.3Fe79.2Nb2.5B6合金磁性能分析可知：650 ℃晶化退火10 min后的合金性能最佳，交換耦合作用最強(qiáng)。
關(guān)鍵字: Nd2Fe14B納米晶合金；顯微組織；交換耦合作用
（State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing,
Beijing 100083, China）
Abstract:The effect of Nb on the magnetic properties, microstructures and exchange coupling interactions of Nd12.3Fe79.2Nb2.5B6 alloy prepared by melt-spinning and subsequent annealing were systematically studied. The results show that the addition of Nb improves the thermal stability of the as-spun amorphous ribbons, as well as improves the optimum crystallization temperature. The ribbons annealed at 650 ℃ are composed of only Nd2Fe14B phase with the grain size uniformly distributing, no intergranular phases are observed. The grain boundary can be almost perfect and coherent, semi-coherent or large angle grain boundary. Therefore, the comprehensive magnetic properties and intergranular exchange coupling interactions of the materials are strengthened. From the analysis of the magnetic properties of the alloy, it is found that, after annealed at 650 ℃ for 10 min, Nd12.3Fe79.2Nb2.5B6 alloy has the optimum magnetic properties and the strongest exchange coupling interactions.
Key words: nano-crystal Nd2Fe14B alloy; microstructure; intergranular exchange coupling interaction
