热变形Nd-Fe-B磁体中异常晶粒的形成及演变
|
摘要
通过研究Nd-Fe-B快淬磁粉、热压及热变形磁体的微观形貌及成分分布,分析了Nd-Fe-B热变形磁体中异常晶粒的形成及变化。快淬带贴辊面存在非晶组织,而自由面结晶度高、晶粒较大。热压时,快淬带结晶度较高的面彼此贴合会形成柱状晶边界,而存在非晶组织的贴辊面互相贴合会形成非晶带边界。热变形时,柱状晶随着变形量的增加逐渐被压扁;而非晶带则结晶形成了粗大等轴晶粒,且随变形量的增加不产生取向。由于异常晶粒的存在,取向晶粒的形成并非同步进行,边界附近的晶粒产生取向会受到异常晶粒的影响而有所滞后。随着变形量的增加,磁体微观结构逐渐均匀,最终完全变形的磁体(变形量为70%)除在带状结构边界处会存在部分异常晶粒外,主要由细小的扁平片状取向晶粒构成。
The microstructure and elements distribution of melt-spun ribbons, hot-pressing magnet and hot deformed magnets were investigated in order to observe the formation and evolution of abnormal grains during deformation process. The roller surface of melt-spun ribbon is made up of very fine grains and even amorphous, while the free surface was nanocrystalline. The columnar grains boundary was formed when the two ribbons contacted with each other by the surfaces with high crystallinity. The amorphous boundary was formed when the roller surface of a ribbon contacts with roller surface of another one. During hot deformation, the columnar grains are gradually compressed with the increase of deformation ratio, and the amorphous boundaries were crystallized and changed into coarse grains which were non-oriented. Due to the existence of abnormal grains, the formation of orientation texture was not synchronized. The deformation and rotation of grains near the boundary would be delayed by the influence of abnormal grain. With the deformation ratio increase, the microstructure of magnet became uniform gradually. The completely deformed magnet(70%) consisted of elongated grains distributed within the strip structure and a few coarse grains and columnar grains distributed at the boundaries of strip structure.
The microstructure and elements distribution of melt-spun ribbons, hot-pressing magnet and hot deformed magnets were investigated in order to observe the formation and evolution of abnormal grains during deformation process. The roller surface of melt-spun ribbon is made up of very fine grains and even amorphous, while the free surface was nanocrystalline. The columnar grains boundary was formed when the two ribbons contacted with each other by the surfaces with high crystallinity. The amorphous boundary was formed when the roller surface of a ribbon contacts with roller surface of another one. During hot deformation, the columnar grains are gradually compressed with the increase of deformation ratio, and the amorphous boundaries were crystallized and changed into coarse grains which were non-oriented. Due to the existence of abnormal grains, the formation of orientation texture was not synchronized. The deformation and rotation of grains near the boundary would be delayed by the influence of abnormal grain. With the deformation ratio increase, the microstructure of magnet became uniform gradually. The completely deformed magnet(70%) consisted of elongated grains distributed within the strip structure and a few coarse grains and columnar grains distributed at the boundaries of strip structure.
引文
[1]李卫,朱明刚.高性能金属永磁材料的探索和研究进展[J].中国材料进展,2009,28(9):6.Li W,Zhu M G.Research progress of high performance metallic permanent magnetic materials[J].Materials China,2009,28(9):62.
[2]Sagawa M,Fujimura S,Togawa N,Yamamoto H,Matsuura Y.New material for permanent magnets on a base of neodymium and iron[J].J.Appl.Phys.,1984,55:2083.
[3]靖征,郭朝晖,朱明刚,王俊明,李卫.Nd-FeB/Pr Co5热压复合磁体研究[J].中国稀土学报,2016,34(3):282.Jing Z,Guo Z H,Zhu M G,Wang J M,Li W.Investigation of Nd-Fe-B/Pr Co5hot-pressed hybrid magnets[J].Journal of the Chinese Society of Rare Earths,2016,34(3):282.
[4]闫阿儒,刘壮,郭帅,陈仁杰.稀土永磁材料的最新研究进展[J].金属功能材料,2017,24(5):5.Yan A R,Liu Z,Guo S,Chen R J.Recent research development of rare-earth permanent magnetic material[J].Metallic Functional Material,2017,24(5):5.
[5]Du X,Jing Z,Han R,Guo Z H,Zhu M G,Li W.Microstructure and magnetic properties of high coercivity die-upset Nd-Fe-B magnets by Nd-Cu alloy addition[J].IEEE Trans.Magn.,2015,51(11):2105003.
[6]Liu X Y,Hu L X,Sun Y,Li Y P,Sun H F.Crystallographic alignment and magnetic anisotropy inducement from as-deformed disproportionated Nd(Fe,Co)B alloy with different deformation ratios[J].J.Alloys Compd.,2016,668:137.
[7]Zhao L Z,Deng X X,Yu H Y,Guan H J,Li X Q,Xiao Z Y,Liu Z W,Greneche J M.Structure and performance of anisotropic nanocrystalline Nd-Fe-B magnets fabricated by high-velocity compaction followed by deformation[J].J.Magn.Magn.Mater.,2017,443:51.
[8]Zhu M G,Li W.Texture formation mechanism and constitutive equation for anisotropic thermorheological rare-earth permanent magnets[J].AIP Adv.,2017,7(5):056236.
[9]Wang X C,Zhu M G,Li W,Li Y F,Lai B,Du A.Microstructure and magnetic properties of anisotropic hotdeformed magnet of different magnetic particle sizes[J].Rare Metals,2015,34(4):255.
[10]Hu Z H,Chu L H,Li J,Liu Y.Enhanced magnetic properties in Nd-Fe-B magnets prepared by spark plasma sintering via die-upsetting process[J].J.Rare Earths,2011,29(7):660.
[11]Yi P P,Lee D,Yan A R.Effects of compositions on characteristics and microstructure for melt-spun ribbons and die-upset magnets of Nd12.8+xFe81.2-x-y-zCoyGazB6[J].J.Magn.Magn.Mater.,2010,322:3019.
[12]Lin M,Wang H J,Yi P P,Yan A R.Effects of excessive grain growth on the magnetic and mechanical properties of hot-deformed Nd Fe B magnets[J].J.Magn.Magn.Mater.,2010,322:2268.
[13]Mouri T,Kumano M,Yasuda Y M,Nagase T,Kato R,Nakazawa Y,Shimizu H.Effect of two-stage deformation on magnetic properties of hot-deformed Nd-Fe-B permanent magnets[J].Scripta Mater.,2014,78-79:37
[14]Zhao W,Liu Y,Li J,Wang R Q,Qiu Y C.Microstructure and magnetic properties of hot-deformed anisotropic Nd-Fe-B magnets prepared from amorphous precursors with different crystallization proportions[J].Rare Metals,2017,36(4):268.
[15]Zheng X F,Li M,Chen R J,Lei F,Jin C X,Wang ZX,Ju J Y,Yin W Z,Lee D,Yan A R.Coercivity enhancement by inhibiting the formation of coarse grains region in hot-deformed Nd-Fe-B magnets with WC nanoparticles addition[J].Scripta Mater.,2017,132:49.
[16]查五生,刘锦云,王正云,周胜海,贾永灿.NdFe B/α-Fe合金快淬薄带表面微观形貌[J].稀有金属材料与工程,2010,39(s1):174.Zha W S,Liu J Y,Wang Z Y,Zhou S H,Jia Y C.Surface morphology of melt-spinning ribbons of Nd Fe B/α-Fe composite alloy[J].Rare Metal Materials and Engineering,2010,39(s1):174.
[17]赖彬,李岩峰,王会杰,汪旭超,李安华,朱明刚,李卫,张跃.辊速和喷射压力对磁粉及热流变磁体的影响[J].功能材料,2014,45(3):83.Lai B,Li Y F,Wang H J,Wang X C,Li A H,Zhu MG,Li W,Zhang Y.Effect of wheel speed and pressure difference on melt-spun Nd Fe B powders and die-upset magnets[J].Journal of Functional Materials,2014,45(3):83.
[18]赖彬,王会杰,赵睿,张文臣,潘伟.Ga对HDDR磁粉热变形磁体磁性能和微观结构的影响[J].功能材料,2010,41(4):591.Lai B,Wang H J,Zhao R,Zhang W C,Pan W.Effects of Ga additions on magnetic performance and microstructure of die-upset magnets[J].Journal of Functional Materials,2010,41(4):591.
[19]刘湘涟,周寿增,张茂才,杨峰,刘俊宁.工业生产N46与N45H烧结Nd Fe B永磁体的结构和性能[J].中国稀土学报,2001,19(5):406.Liu X L,Zhou S Z,Zhang M C,Yang F,Liu J N.Microstructure and magnetic properties of mass-produced N46 and N45H sintered Nd Fe B magnets[J].Journal of the Chinese Society of Rare Earths,2001,19(5):406.
[20]汪卫华.非晶态物质的本本质和特性[J].物理学进展,2013,33(5):177.Wang W H.The nature and properties of amorphous matter[J].Progress in Physics,2013,33(5):177.
[21]Lai B,Li Y F,Wang H J,Li A H,Zhu M G,Li W.Quasi-periodic layer structure of die-upset Nd Fe B magnets[J].J.Rare Earths,2013,31(7):679.
[22]卢柯.非晶态合金向纳米晶体的相转变[J].金属学报,1994,30(1):B1.Lu K.Phase transformation from an amorphous alloy into nanocrystalline materials[J].Acta Metallurgica Sinica,1994,30(1):B1.
[23]Guo Z H,Li M Y,Wang J M,Jing Z,Yue M,Zhu MG,Li W.Effect of deformation ratios on grain alignment and magnetic properties of hot pressing/hot deformation Nd-Fe-B magnets[J].AIP Adv.,2018,8(5):056234.
[2]Sagawa M,Fujimura S,Togawa N,Yamamoto H,Matsuura Y.New material for permanent magnets on a base of neodymium and iron[J].J.Appl.Phys.,1984,55:2083.
[3]靖征,郭朝晖,朱明刚,王俊明,李卫.Nd-FeB/Pr Co5热压复合磁体研究[J].中国稀土学报,2016,34(3):282.Jing Z,Guo Z H,Zhu M G,Wang J M,Li W.Investigation of Nd-Fe-B/Pr Co5hot-pressed hybrid magnets[J].Journal of the Chinese Society of Rare Earths,2016,34(3):282.
[4]闫阿儒,刘壮,郭帅,陈仁杰.稀土永磁材料的最新研究进展[J].金属功能材料,2017,24(5):5.Yan A R,Liu Z,Guo S,Chen R J.Recent research development of rare-earth permanent magnetic material[J].Metallic Functional Material,2017,24(5):5.
[5]Du X,Jing Z,Han R,Guo Z H,Zhu M G,Li W.Microstructure and magnetic properties of high coercivity die-upset Nd-Fe-B magnets by Nd-Cu alloy addition[J].IEEE Trans.Magn.,2015,51(11):2105003.
[6]Liu X Y,Hu L X,Sun Y,Li Y P,Sun H F.Crystallographic alignment and magnetic anisotropy inducement from as-deformed disproportionated Nd(Fe,Co)B alloy with different deformation ratios[J].J.Alloys Compd.,2016,668:137.
[7]Zhao L Z,Deng X X,Yu H Y,Guan H J,Li X Q,Xiao Z Y,Liu Z W,Greneche J M.Structure and performance of anisotropic nanocrystalline Nd-Fe-B magnets fabricated by high-velocity compaction followed by deformation[J].J.Magn.Magn.Mater.,2017,443:51.
[8]Zhu M G,Li W.Texture formation mechanism and constitutive equation for anisotropic thermorheological rare-earth permanent magnets[J].AIP Adv.,2017,7(5):056236.
[9]Wang X C,Zhu M G,Li W,Li Y F,Lai B,Du A.Microstructure and magnetic properties of anisotropic hotdeformed magnet of different magnetic particle sizes[J].Rare Metals,2015,34(4):255.
[10]Hu Z H,Chu L H,Li J,Liu Y.Enhanced magnetic properties in Nd-Fe-B magnets prepared by spark plasma sintering via die-upsetting process[J].J.Rare Earths,2011,29(7):660.
[11]Yi P P,Lee D,Yan A R.Effects of compositions on characteristics and microstructure for melt-spun ribbons and die-upset magnets of Nd12.8+xFe81.2-x-y-zCoyGazB6[J].J.Magn.Magn.Mater.,2010,322:3019.
[12]Lin M,Wang H J,Yi P P,Yan A R.Effects of excessive grain growth on the magnetic and mechanical properties of hot-deformed Nd Fe B magnets[J].J.Magn.Magn.Mater.,2010,322:2268.
[13]Mouri T,Kumano M,Yasuda Y M,Nagase T,Kato R,Nakazawa Y,Shimizu H.Effect of two-stage deformation on magnetic properties of hot-deformed Nd-Fe-B permanent magnets[J].Scripta Mater.,2014,78-79:37
[14]Zhao W,Liu Y,Li J,Wang R Q,Qiu Y C.Microstructure and magnetic properties of hot-deformed anisotropic Nd-Fe-B magnets prepared from amorphous precursors with different crystallization proportions[J].Rare Metals,2017,36(4):268.
[15]Zheng X F,Li M,Chen R J,Lei F,Jin C X,Wang ZX,Ju J Y,Yin W Z,Lee D,Yan A R.Coercivity enhancement by inhibiting the formation of coarse grains region in hot-deformed Nd-Fe-B magnets with WC nanoparticles addition[J].Scripta Mater.,2017,132:49.
[16]查五生,刘锦云,王正云,周胜海,贾永灿.NdFe B/α-Fe合金快淬薄带表面微观形貌[J].稀有金属材料与工程,2010,39(s1):174.Zha W S,Liu J Y,Wang Z Y,Zhou S H,Jia Y C.Surface morphology of melt-spinning ribbons of Nd Fe B/α-Fe composite alloy[J].Rare Metal Materials and Engineering,2010,39(s1):174.
[17]赖彬,李岩峰,王会杰,汪旭超,李安华,朱明刚,李卫,张跃.辊速和喷射压力对磁粉及热流变磁体的影响[J].功能材料,2014,45(3):83.Lai B,Li Y F,Wang H J,Wang X C,Li A H,Zhu MG,Li W,Zhang Y.Effect of wheel speed and pressure difference on melt-spun Nd Fe B powders and die-upset magnets[J].Journal of Functional Materials,2014,45(3):83.
[18]赖彬,王会杰,赵睿,张文臣,潘伟.Ga对HDDR磁粉热变形磁体磁性能和微观结构的影响[J].功能材料,2010,41(4):591.Lai B,Wang H J,Zhao R,Zhang W C,Pan W.Effects of Ga additions on magnetic performance and microstructure of die-upset magnets[J].Journal of Functional Materials,2010,41(4):591.
[19]刘湘涟,周寿增,张茂才,杨峰,刘俊宁.工业生产N46与N45H烧结Nd Fe B永磁体的结构和性能[J].中国稀土学报,2001,19(5):406.Liu X L,Zhou S Z,Zhang M C,Yang F,Liu J N.Microstructure and magnetic properties of mass-produced N46 and N45H sintered Nd Fe B magnets[J].Journal of the Chinese Society of Rare Earths,2001,19(5):406.
[20]汪卫华.非晶态物质的本本质和特性[J].物理学进展,2013,33(5):177.Wang W H.The nature and properties of amorphous matter[J].Progress in Physics,2013,33(5):177.
[21]Lai B,Li Y F,Wang H J,Li A H,Zhu M G,Li W.Quasi-periodic layer structure of die-upset Nd Fe B magnets[J].J.Rare Earths,2013,31(7):679.
[22]卢柯.非晶态合金向纳米晶体的相转变[J].金属学报,1994,30(1):B1.Lu K.Phase transformation from an amorphous alloy into nanocrystalline materials[J].Acta Metallurgica Sinica,1994,30(1):B1.
[23]Guo Z H,Li M Y,Wang J M,Jing Z,Yue M,Zhu MG,Li W.Effect of deformation ratios on grain alignment and magnetic properties of hot pressing/hot deformation Nd-Fe-B magnets[J].AIP Adv.,2018,8(5):056234.