单相铸锭制得高剩磁Sm_2Co_(17)基永磁合金磁性能和微观结构
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摘要
研究了用均质化处理后铸锭制成的名义成分为Sm(CobalFe0.245Cu0.07Zr0.02)7.8(原子分数%)的Sm_2Co_(17)基烧结永磁合金不同等温退火热处理温度Tia(785,800,815,830℃)的磁性能和微观结构。结果显示,随着Tia从785℃增加到830℃,磁体的剩磁Br(～1.157T)基本保持不变,内禀矫顽力Hcj呈现出先增大后减小的变化规律。TEM观察结果显示等温退火热处理温度分别为785℃和815℃时的终态磁体的微观结构有如下区别:胞状微结构的平均尺寸不同,785℃的终态磁体的胞状微结构的平均尺寸约115nm,而815℃的终态磁体的胞状微结构的平均尺寸约82nm;另外,1∶5H胞壁相所占的体积分数不同,785℃的终态磁体中1∶5H胞壁相所占的体积分数明显小于815℃的终态磁体中的。这是内禀矫顽力Hcj在815℃时达到极大值的两个主要原因。
The magnetic properties and microstructures of Sm_2Co_(17)-based sintered permanent magnet annealed at different isothermal annealing temperatures Tia(785,800,815,830℃),made of as-homogenized ingot,with the nominal composition Sm(CobalFe0.245 Cu0.07 Zr0.02)7.8(atom fraction%),have been investigated.The results showed that,with the isothermal annealing temperatures increasing from 785℃to 830℃,the remanence Bralmost keeps constant(～1.157 T),the intrinsic coercivity Hcjfirst increases,and then decreases.TEM images indicate that there are two differences between the microstructures of the final state magnet annealed at 785℃ and 815℃,respectively:firstly,the average cell size of the final magnet annealed at 785℃is about 115 nm,while that of the final magnet annealed at 815℃is about 82 nm;secondly,the volume fraction of 1∶5 Hcell boundary phase of the final magnet annealed at 785℃is smaller than that of the final magnet annealed at 815℃.These two reasons above areconsidered to be two main reasons accounting for the maximum Hcjof the final state magnet annealed at 815℃.
The magnetic properties and microstructures of Sm_2Co_(17)-based sintered permanent magnet annealed at different isothermal annealing temperatures Tia(785,800,815,830℃),made of as-homogenized ingot,with the nominal composition Sm(CobalFe0.245 Cu0.07 Zr0.02)7.8(atom fraction%),have been investigated.The results showed that,with the isothermal annealing temperatures increasing from 785℃to 830℃,the remanence Bralmost keeps constant(～1.157 T),the intrinsic coercivity Hcjfirst increases,and then decreases.TEM images indicate that there are two differences between the microstructures of the final state magnet annealed at 785℃ and 815℃,respectively:firstly,the average cell size of the final magnet annealed at 785℃is about 115 nm,while that of the final magnet annealed at 815℃is about 82 nm;secondly,the volume fraction of 1∶5 Hcell boundary phase of the final magnet annealed at 785℃is smaller than that of the final magnet annealed at 815℃.These two reasons above areconsidered to be two main reasons accounting for the maximum Hcjof the final state magnet annealed at 815℃.
引文
[1]Tian J J,Zhang S G,Qu X H.Effects of oxygen and carbon on the magnetic properties and microstructure of Sm2Co17permanent magnets[J].Rare Metals,2007,26(4):299.
[2]Pragnell W M,Evans H E,Williams A J.Oxidation protection of Sm2Co17-based alloys[J].Journal of Alloys and Compounds,2012,517(7):92.
[3]Rabenberg L,Mishra R K,Thomas G.Microstructures of precipitation-hardened SmCo permanent magnets[J].Journal of Applied Physics,1982,53(3):2389.
[4]Kronmüller H,Goll D.Micromagnetic analysis of pinning-hardened nanostructured,nanocrystalline Sm2Co17based alloys[J].Scripta Materialia,2002,47(8):545.
[5]Kronmüller H,Goll D.Analysis of the temperature dependence of the coercive field of Sm2Co17based magnets[J].Scripta Materialia,2003,48(7):833.
[6]Goll D,H.Samarium-cobalt 2∶17magnets:Analysis of the coercive field of Sm2(CoFeCuZr)17 high-temperature permanent magnets[J].Scripta Materialia,2010,63(2):243.
[7]Stadelmaier H H,Kronmüller H,Goll D.Samarium-cobalt 2∶17magnets:Identifying Smn+1Co5n-1 phases stabilized by Zr[J].Scripta Materialia,2010,63(2):843.
[8]Paul D I.Extended theory of the coercive force due to domain wall pinning[J].Journal of Applied Physics,1982,53(3):2362.
[9]Gopalan R,Hono K,Yan A,et al.Direct evidence for Cu concentration variation and its correlation to coercivity in Sm(Co0.74Fe0.1Cu0.12Zr0.04)7.4ribbons[J].Scripta Materialia,2009,60(9):764.
[10]Livingston J D,Martin D L.Microstructure of aged(Co,Cu,Fe)7Sm magnets[J].Journal of Applied Physics,1977,48(3):1350.
[11]Goll D,Kronmüller H,Stadelmaier H H.Micromagnetism and the microstructure of high temperature permanent magnets[J].Journal of Applied Physics,2004,96(11):6534.
[12]Xiong X Y,Ohkubo T,Koyama T,et al.The microstructure of sintered Sm(Co0.72Fe0.20Cu0.055Zr0.025)7.5permanent magnet studied by atom probe[J].Acta Materialia,2004,52(3):737.
[13]闫阿儒,刘壮,郭帅,等.稀土永磁材料的最新研究进展[J].金属功能材料,2017,24(5):5.
[14]李丽娅,易健宏,彭元东,等.纳米晶稀土永磁材料的制备技术研究进展[J].粉末冶金工业,2005,15(5):38.
[15]田建军,陶斯武,张深根,等.Sm(Co,Cu,Fe,Zr)z永磁体注射成形坯溶剂脱脂工艺的研究[J].粉末冶金工业,2006,16(2):12.
[16]Feng H,Chen H,Guo Z,et al.Twinning structure in Sm(Co,Fe,Cu,Zr)z permanent magnet[J].Intermetallics,2010,18(5):1067.
[17]Fang Y K,Chang H W,Guo Z H,et al.Magnetic microstructures of phase-separated Sm-Co 2∶17-type sintered magnets[J].Journal of Alloys&Compounds,2008,462(1):376.
[18]Guo Z H,Pan W,Li W.Sm(Co,Fe,Cu,Zr)zsintered magnets with a maximum operating temperature of 500℃[J].Journal of Magnetism and Magnetic Materials,2006,303:e396.
[19]Sun W,Zhu M G,Fang Y K,et al.Magnetic properties and microstructures of high-performance Sm2Co17 based alloy[J].Journal of Magnetism and Magnetic Materials,2015,378(3):214.
[20]Sun W,Zhu M G,Fang Y K,et al.Microstructures and coercivity mechanism of 2∶17-type Sm-Co magnets with high remanence[J].Rare Metals,2015,34(1):1.
[21]Sun W,Zhu M G,Fang Y K,et al.Microstructure and magnetic properties of sintered CeCo4.325-xCu0.675Fex magnets[J].Rare Metals,2015,34(3):164.
[22]孙威,朱明刚,方以坤,等.高剩磁钐钴合金等温退火过程的组织演化和磁性能的关联[J].稀有金属,2014,38(6):1017.
[23]Sun W,Zhu M G,Guo Z H,et al.The coercivity mechanism of sintered Sm(CobalFe0.245Cu0.07Zr0.02)7.8permanent magnets with different isothermal annealing time[J].Phy.B,2015,476(11):154.
[24]Sun W,Zhu M G,Fang Y K,et al.Microstructures and magnetic properties of Sm(CobalFe0.245Cu0.07Zr0.02)7.8 sintered magnet solution-treated at high temperature[J].Rare Metals,2016,doi:10.1007/s12598-016-0813-5.
[25]朱明刚,孙威,方以坤,等.Sm2Co17基永磁材料的研究进展.中国材料进展,2015,34(11):789.
[26]夏满龙,孙威,方以坤,等.退火过程对高温Sm2Co17磁体性能的影响[J].金属功能材料,2013,20(4):21.
[27]Gopalan R,Muraleedharan K,Sastry T S R K,et al.Studies on structural transformation and magnetic properties in Sm2Co17type alloys[J].Journal of Materials Science,2001,36(17):4117.
[2]Pragnell W M,Evans H E,Williams A J.Oxidation protection of Sm2Co17-based alloys[J].Journal of Alloys and Compounds,2012,517(7):92.
[3]Rabenberg L,Mishra R K,Thomas G.Microstructures of precipitation-hardened SmCo permanent magnets[J].Journal of Applied Physics,1982,53(3):2389.
[4]Kronmüller H,Goll D.Micromagnetic analysis of pinning-hardened nanostructured,nanocrystalline Sm2Co17based alloys[J].Scripta Materialia,2002,47(8):545.
[5]Kronmüller H,Goll D.Analysis of the temperature dependence of the coercive field of Sm2Co17based magnets[J].Scripta Materialia,2003,48(7):833.
[6]Goll D,H.Samarium-cobalt 2∶17magnets:Analysis of the coercive field of Sm2(CoFeCuZr)17 high-temperature permanent magnets[J].Scripta Materialia,2010,63(2):243.
[7]Stadelmaier H H,Kronmüller H,Goll D.Samarium-cobalt 2∶17magnets:Identifying Smn+1Co5n-1 phases stabilized by Zr[J].Scripta Materialia,2010,63(2):843.
[8]Paul D I.Extended theory of the coercive force due to domain wall pinning[J].Journal of Applied Physics,1982,53(3):2362.
[9]Gopalan R,Hono K,Yan A,et al.Direct evidence for Cu concentration variation and its correlation to coercivity in Sm(Co0.74Fe0.1Cu0.12Zr0.04)7.4ribbons[J].Scripta Materialia,2009,60(9):764.
[10]Livingston J D,Martin D L.Microstructure of aged(Co,Cu,Fe)7Sm magnets[J].Journal of Applied Physics,1977,48(3):1350.
[11]Goll D,Kronmüller H,Stadelmaier H H.Micromagnetism and the microstructure of high temperature permanent magnets[J].Journal of Applied Physics,2004,96(11):6534.
[12]Xiong X Y,Ohkubo T,Koyama T,et al.The microstructure of sintered Sm(Co0.72Fe0.20Cu0.055Zr0.025)7.5permanent magnet studied by atom probe[J].Acta Materialia,2004,52(3):737.
[13]闫阿儒,刘壮,郭帅,等.稀土永磁材料的最新研究进展[J].金属功能材料,2017,24(5):5.
[14]李丽娅,易健宏,彭元东,等.纳米晶稀土永磁材料的制备技术研究进展[J].粉末冶金工业,2005,15(5):38.
[15]田建军,陶斯武,张深根,等.Sm(Co,Cu,Fe,Zr)z永磁体注射成形坯溶剂脱脂工艺的研究[J].粉末冶金工业,2006,16(2):12.
[16]Feng H,Chen H,Guo Z,et al.Twinning structure in Sm(Co,Fe,Cu,Zr)z permanent magnet[J].Intermetallics,2010,18(5):1067.
[17]Fang Y K,Chang H W,Guo Z H,et al.Magnetic microstructures of phase-separated Sm-Co 2∶17-type sintered magnets[J].Journal of Alloys&Compounds,2008,462(1):376.
[18]Guo Z H,Pan W,Li W.Sm(Co,Fe,Cu,Zr)zsintered magnets with a maximum operating temperature of 500℃[J].Journal of Magnetism and Magnetic Materials,2006,303:e396.
[19]Sun W,Zhu M G,Fang Y K,et al.Magnetic properties and microstructures of high-performance Sm2Co17 based alloy[J].Journal of Magnetism and Magnetic Materials,2015,378(3):214.
[20]Sun W,Zhu M G,Fang Y K,et al.Microstructures and coercivity mechanism of 2∶17-type Sm-Co magnets with high remanence[J].Rare Metals,2015,34(1):1.
[21]Sun W,Zhu M G,Fang Y K,et al.Microstructure and magnetic properties of sintered CeCo4.325-xCu0.675Fex magnets[J].Rare Metals,2015,34(3):164.
[22]孙威,朱明刚,方以坤,等.高剩磁钐钴合金等温退火过程的组织演化和磁性能的关联[J].稀有金属,2014,38(6):1017.
[23]Sun W,Zhu M G,Guo Z H,et al.The coercivity mechanism of sintered Sm(CobalFe0.245Cu0.07Zr0.02)7.8permanent magnets with different isothermal annealing time[J].Phy.B,2015,476(11):154.
[24]Sun W,Zhu M G,Fang Y K,et al.Microstructures and magnetic properties of Sm(CobalFe0.245Cu0.07Zr0.02)7.8 sintered magnet solution-treated at high temperature[J].Rare Metals,2016,doi:10.1007/s12598-016-0813-5.
[25]朱明刚,孙威,方以坤,等.Sm2Co17基永磁材料的研究进展.中国材料进展,2015,34(11):789.
[26]夏满龙,孙威,方以坤,等.退火过程对高温Sm2Co17磁体性能的影响[J].金属功能材料,2013,20(4):21.
[27]Gopalan R,Muraleedharan K,Sastry T S R K,et al.Studies on structural transformation and magnetic properties in Sm2Co17type alloys[J].Journal of Materials Science,2001,36(17):4117.