器 硅钢片，厚0.3mm HV毛-夕 区于-夕 口儿理 水久石 磁石 口一夕 率组 接引擎 发电机 驱动电机 硅钢科学永磁体2kg 13 School of Materials Science and Engineering
材料科学与工程学院 School of Materials Science and Engineering 13
上游充通大粤 基本磁学参量—软磁与永磁材料 SHANGHAI JLAO TONG UNIVERSITY M M M W uoneznousew H Hard magnet soft magnet Applied field H Applied field H M饱和磁化强度，H矫顽力， S正比于最大磁能积(BH)max 对于永磁，希望Hc、(BH)max尽可能高 p.14
Ms饱和磁化强度，Hc矫顽力，S正比于最大磁能积(BH)max 对于永磁，希望Hc、(BH)max尽可能高 基本磁学参量——软磁与永磁材料 p. 14
001] ③ 864216642 [001] ew/ry 480 H,卡77.1k0e 60 .100-80-60-40-20-21 204060 80100120nets 400 4 H(kOe) 50 8 Nd2Fe14B 320 -10- -12 40 14 4 Nd,Fe,B SX@RT 240 -18] Sm2Co17 30 (Sm,Pr)Cos 160 Ba,Sr-Ferrite s Sm2Fe17N3◆ Sintered SmCos 20 FeCrCo wnwixew Co,Ferrite MK Alnico MnAl 80 10 KS NKS wnwixew Steel 0 0 1900 1920 1940 1960 1980 2000 2020 Year 材料科学与工程学院 School of Materials Science and Engineering
材料科学与工程学院 School of Materials Science and Engineering
Microstructure and coercivity of Nd-Fe-B magnets Nd,Fe4B Nd2Fe14B H 30 sintered Nucleation type M M M: magnets 0→1 10 Ne一→0 .H ~3μm Ha=2K/Ms~7T Ho Hc。=tHa-Nef Ms Demagnetized state Nd-rich phases Nd,FeB 5μm GB phase 2μm 16
16 Microstructure and coercivity of Nd-Fe-B magnets D GB 組成 Nucleation type H M H iHc Mr Ms Demagnetized state Ha=2Ku /Ms~7 T Hc =a↑Ha− Neff↓Ms 5µm Nd2Fe14B Nd2Fe14B Nd2Fe14B a→1 Neff→0 sintered magnets Hc (kOe)
Magnetic domain evolution in Nd-Fe-B:Cu sintered magnet (by XMCD) 1.Nucleation of initial multiple domain 2.Domain wall motion X-ray fluorescence microscopy + Propagation of reversal domains -40 kA/m Fe Nd Cu -200 kA/m SEM 280 kA/m 4 2 560 kA/m 0 5um 4x020 -1.0 0.0 1.0 2.0 -880kA/m External field(MA/m) M.Suzuki et al,Acta Materialia 106(2016)155 材料科学与工程学院 17 School of Materials Science and Engineering
材料科学与工程学院 School of Materials Science and Engineering Magnetic domain evolution in Nd–Fe–B:Cu sintered magnet (by XMCD) M. Suzuki et al, Acta Materialia 106(2016) 155 17