Microstructural investigation of Nd-rich phase in sintered Nd-Fe-B magnets through electron microscopy
来源期刊：Journal of Rare Earths2013年第8期
论文作者：付新 韩小磊 杜志伟 冯海波 李岩峰
文章页码：765 - 771
摘 要：The distribution, morphologies and structures of intergranular Nd-rich phase in sintered Nd-Fe-B magnets were studied through electron microscopy. Backscattered electron （BSE） imaging revealed that Nd-rich particles with various morphologies and sizes were randomly distributed at the grain boundaries and the triple junctions of the tetragonal Nd2Fe14B matrix. Through selected area electron diffraction （SAED） analysis under a systematic tilting condition, most intergranular Nd-rich phase particles, with sizes ranging from hundreds of nanometres to several micrometres, were identified as face-centred cubic （FCC） structure. Such particles possessed several approximate orientation relationships with their adjacent Nd2Fe14B matrix grains, such as （002） Nd2Fe14B//（200） FCCNd-rich [120] Nd2Fe14B//[001] FCCNd-rich , （002） Nd2Fe14B//（ 220 ） FCCNd-rich [110] Nd2Fe14B//[112] FCCNd-rich , as well as （011） Nd2Fe14B//（131） FCCNd-rich [111] Nd2Fe14B//[114] FCCNd-rich , which could be attributed to minimising interfacial energy. The combination of highresolution electron microscopy with energy-dispersive X-ray spectroscopy revealed the internal inhomogeneous nature of Nd-rich phases. The large lattice distortion and nanoscale-ordered structures within a single Nd-rich grain were observed.
付新1，韩小磊1，杜志伟1，冯海波2，李岩峰2
1. National Center of Analysis and Testing for Non-ferrous Metals & Electronic Materials, General Research Institute for Nonferrous Metals2. Division of Functional Materials, Central Iron and Steel Research Institute
摘 要：The distribution, morphologies and structures of intergranular Nd-rich phase in sintered Nd-Fe-B magnets were studied through electron microscopy. Backscattered electron （BSE） imaging revealed that Nd-rich particles with various morphologies and sizes were randomly distributed at the grain boundaries and the triple junctions of the tetragonal Nd2Fe14B matrix. Through selected area electron diffraction （SAED） analysis under a systematic tilting condition, most intergranular Nd-rich phase particles, with sizes ranging from hundreds of nanometres to several micrometres, were identified as face-centred cubic （FCC） structure. Such particles possessed several approximate orientation relationships with their adjacent Nd2Fe14B matrix grains, such as （002） Nd2Fe14B//（200） FCCNd-rich [120] Nd2Fe14B//[001] FCCNd-rich , （002） Nd2Fe14B//（ 220 ） FCCNd-rich [110] Nd2Fe14B//[112] FCCNd-rich , as well as （011） Nd2Fe14B//（131） FCCNd-rich [111] Nd2Fe14B//[114] FCCNd-rich , which could be attributed to minimising interfacial energy. The combination of highresolution electron microscopy with energy-dispersive X-ray spectroscopy revealed the internal inhomogeneous nature of Nd-rich phases. The large lattice distortion and nanoscale-ordered structures within a single Nd-rich grain were observed.
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