掺杂Pr_(16)Dy_(64)Fe_(20)对烧结钕铁硼磁性能和微观组织的影响
|
摘要
为了提高烧结钕铁硼磁体的矫顽力和热稳定性,采用双合金的方法添加Pr_(16)Dy_(64)Fe_(20)(%,质量分数)三元稀土合金制备低重稀土烧结钕铁硼磁体,当合金添加量为3%时,钕铁硼磁体的矫顽力从未添加时的1038 kA·m~(-1)提高到1308 kA·m~(-1),剩磁仅下降了0.03 T。添加Pr_(16)Dy_(64)Fe_(20)合金后磁体的微观组织得到明显改善,富钕相数量增多,分布更加连续均匀,晶粒间交换耦合作用减弱。Dy元素大部分分布在晶界角隅处,并进入主相晶粒外延周围形成更高磁晶各向异性场的(PrNd,Dy)_2Fe_(14)B相,提高了磁体的矫顽力,热稳定性也得到明显改善。
In order to improve the coercivity and thermal stability of sintered NdFeB magnets, a ternary rare earth Pr_(16)Dy_(64)Fe_(20) alloy was doped into sintered NdFeB magnets by double alloy method. The coercivity of the magnets increased from 1038 kA·m~(-1) to 1308 kA·m~(-1) compared to the undoped magnet, and the remanence only decreased by 0.03 T when doping 3% Pr_(16)Dy_(64)Fe_(20) alloy. After the addition of Pr_(16)Dy_(64)Fe_(20) alloy, the microstructure of the magnets improved obviously, the amount of Nd-rich phase increased, the distribution was more continuous and uniform, and the exchange coupling between grains was weakened. The Dy elements were mostly distributed at the triple junction grain boundary phases and then entered the epitaxial layer of the main phases to form a higher anisotropic field strength-(PrNd, Dy)_2Fe_(14)B phase. It should be responsible for the increasing coercivity of the magnets, and also the improving thermal stability.
In order to improve the coercivity and thermal stability of sintered NdFeB magnets, a ternary rare earth Pr_(16)Dy_(64)Fe_(20) alloy was doped into sintered NdFeB magnets by double alloy method. The coercivity of the magnets increased from 1038 kA·m~(-1) to 1308 kA·m~(-1) compared to the undoped magnet, and the remanence only decreased by 0.03 T when doping 3% Pr_(16)Dy_(64)Fe_(20) alloy. After the addition of Pr_(16)Dy_(64)Fe_(20) alloy, the microstructure of the magnets improved obviously, the amount of Nd-rich phase increased, the distribution was more continuous and uniform, and the exchange coupling between grains was weakened. The Dy elements were mostly distributed at the triple junction grain boundary phases and then entered the epitaxial layer of the main phases to form a higher anisotropic field strength-(PrNd, Dy)_2Fe_(14)B phase. It should be responsible for the increasing coercivity of the magnets, and also the improving thermal stability.
引文
[1]Sugimoto S.Current status and recent topics of rareearth permanent magnets[J].J.Phys.D Appl.Phys.,2011,44:064001.
[2]Gutfleisch O,Willard M A,Brück E,Chen C H,Sankar S G,Liu J P.Magnetic materials and devices for the 21st century:stronger,lighter,and more energy efficient[J].Adv.Mater.,2011,23:821.
[3]Nakamura H.The current and future status of rare earth permanent magnets[J].Scr.Mater.,2018,154:273.
[4]朱明刚,李卫.多(硬磁)主相永磁体及矫顽力机制研究现状与展望[J].科学通报,2015,60(33):3161.Zhu M G,Li W.Status and prospect for multi-(hard magnetic)main-phase permanent magnet and coercivity mechanism[J].Chinese Science Bulletin,2015,60(33):3161.
[5]李家节,周头军,郭诚君,喻玺,戚植奇,杜君峰.烧结Nd Fe B磁体晶界扩散Dy Zn合金磁性能与抗蚀性能研究[J].中国稀土学报,2017,35(6):723.Li J J,Zhou T J,Guo C J,Yu X,Qi Z Q,Du J F.Magnetic property and corrosion resistance of sintered Nd Fe B magnet by diffusing Dy Zn alloy[J].Journal of the Chinese Society of Rare Earths,2017,35(6):723.
[6]Wu B H,Zhang Q K,Li W D,Ding X F,Yang L J,Wattoo A G,Zhang L J,Mao S D,Song Z L.Grain boundary diffusion of magnetron sputter coated heavy rare earth elements in sintered Nd-Fe-B magnet[J].J.Appl.Phys.,2018,123:245112.
[7]Lu K C,Bao X Q,Tang M H,Chen G X,Mu X,Li JH,Gao X X.Boundary optimization and coercivity enhancement of high(BH)max Nd-Fe-B magnet by diffusing Pr-Tb-Cu-Al alloys[J].Scr.Mater.,2017,138:83.
[8]Zhou B B,Li X B,Liang X L,Yan G L,Chen K,Yan A R.Improvement of the magnetic property thermal stability and corrosion resistance of the sintered Nd-Fe-Bmagnets with Dy80Al20addition[J].J.Magn.Magn.Mater.,2017,429:257.
[9]马冬威,胡志华,瞿海锦,罗成,王会杰,王敏.烧结Nd-Fe-B磁体多主相复合制备及微观结构研究[J].中国稀土学报,2017,35(6):728.Ma D W,Hu Z H,Qu H J,Luo C,Wang H J,Wang M.Composite preparation and microstructure of sintered Nd-Fe-B magnets with multiple main phase[J].Journal of the Chinese Society of Rare Earths,2017,35(6):728.
[10]Croat J J,Herbst J F,Lee R W,Pinkerton F E.Pr-Fe and Nd-Fe based materials:A new class of high-performance permanent magnets[J].J.Appl.Phys.,1984,55(6):2078.
[11]Chen B C,Liu X M,Chen R J,Guo S,Lee D,Yan AR.The mechanism of enhanced magnetic properties of sintered permanent magnets by substitution of Pr for Nd[J].J.Alloys Compd.,2012,516:73.
[12]Cui X G,Cui C Y,Cheng X N,Xu X J.Effect of Dy2O3Intergranular addition on thermal stability and corrosion resistance of Nd-Fe-B Magnets[J].Intermetallics,2014,55:118.
[13]Hu Z H,Lian F Z,Zhu M G,Li W.Effect of Co on the thermal stability and impact toughness of sintered Nd-Fe-B magnets[J].J.Magn.Magn.Mater.,2008,320:2364.
[14]Wang J D,Feng H B,Li A H,Li Y F,Zhu M G,Li W.Oxide evolution in Nd Dy-Fe-B magnet during aging process[J].J.Rare Earths,2012,30(10):1020.
[15]Zhang Y J,Ma T Y,Liu X L,Liu P,Jin J J,Zou J D,Yan M.Coercivity enhancement of Nd-Fe-B sintered magnets with intergranular adding(Pr,Dy,Cu)-Hx powders[J].J.Magn.Magn.Mater.,2016,399:159.
[16]Liang L P,Ma T Y,Zhang P,Yan M.Effects of Dy71.5Fe28.5intergranular addition on the microstructure and the corrosion resistance of Nd-Fe-B sintered magnets[J].J.Magn.Magn.Mater.,2015,384:133.
[2]Gutfleisch O,Willard M A,Brück E,Chen C H,Sankar S G,Liu J P.Magnetic materials and devices for the 21st century:stronger,lighter,and more energy efficient[J].Adv.Mater.,2011,23:821.
[3]Nakamura H.The current and future status of rare earth permanent magnets[J].Scr.Mater.,2018,154:273.
[4]朱明刚,李卫.多(硬磁)主相永磁体及矫顽力机制研究现状与展望[J].科学通报,2015,60(33):3161.Zhu M G,Li W.Status and prospect for multi-(hard magnetic)main-phase permanent magnet and coercivity mechanism[J].Chinese Science Bulletin,2015,60(33):3161.
[5]李家节,周头军,郭诚君,喻玺,戚植奇,杜君峰.烧结Nd Fe B磁体晶界扩散Dy Zn合金磁性能与抗蚀性能研究[J].中国稀土学报,2017,35(6):723.Li J J,Zhou T J,Guo C J,Yu X,Qi Z Q,Du J F.Magnetic property and corrosion resistance of sintered Nd Fe B magnet by diffusing Dy Zn alloy[J].Journal of the Chinese Society of Rare Earths,2017,35(6):723.
[6]Wu B H,Zhang Q K,Li W D,Ding X F,Yang L J,Wattoo A G,Zhang L J,Mao S D,Song Z L.Grain boundary diffusion of magnetron sputter coated heavy rare earth elements in sintered Nd-Fe-B magnet[J].J.Appl.Phys.,2018,123:245112.
[7]Lu K C,Bao X Q,Tang M H,Chen G X,Mu X,Li JH,Gao X X.Boundary optimization and coercivity enhancement of high(BH)max Nd-Fe-B magnet by diffusing Pr-Tb-Cu-Al alloys[J].Scr.Mater.,2017,138:83.
[8]Zhou B B,Li X B,Liang X L,Yan G L,Chen K,Yan A R.Improvement of the magnetic property thermal stability and corrosion resistance of the sintered Nd-Fe-Bmagnets with Dy80Al20addition[J].J.Magn.Magn.Mater.,2017,429:257.
[9]马冬威,胡志华,瞿海锦,罗成,王会杰,王敏.烧结Nd-Fe-B磁体多主相复合制备及微观结构研究[J].中国稀土学报,2017,35(6):728.Ma D W,Hu Z H,Qu H J,Luo C,Wang H J,Wang M.Composite preparation and microstructure of sintered Nd-Fe-B magnets with multiple main phase[J].Journal of the Chinese Society of Rare Earths,2017,35(6):728.
[10]Croat J J,Herbst J F,Lee R W,Pinkerton F E.Pr-Fe and Nd-Fe based materials:A new class of high-performance permanent magnets[J].J.Appl.Phys.,1984,55(6):2078.
[11]Chen B C,Liu X M,Chen R J,Guo S,Lee D,Yan AR.The mechanism of enhanced magnetic properties of sintered permanent magnets by substitution of Pr for Nd[J].J.Alloys Compd.,2012,516:73.
[12]Cui X G,Cui C Y,Cheng X N,Xu X J.Effect of Dy2O3Intergranular addition on thermal stability and corrosion resistance of Nd-Fe-B Magnets[J].Intermetallics,2014,55:118.
[13]Hu Z H,Lian F Z,Zhu M G,Li W.Effect of Co on the thermal stability and impact toughness of sintered Nd-Fe-B magnets[J].J.Magn.Magn.Mater.,2008,320:2364.
[14]Wang J D,Feng H B,Li A H,Li Y F,Zhu M G,Li W.Oxide evolution in Nd Dy-Fe-B magnet during aging process[J].J.Rare Earths,2012,30(10):1020.
[15]Zhang Y J,Ma T Y,Liu X L,Liu P,Jin J J,Zou J D,Yan M.Coercivity enhancement of Nd-Fe-B sintered magnets with intergranular adding(Pr,Dy,Cu)-Hx powders[J].J.Magn.Magn.Mater.,2016,399:159.
[16]Liang L P,Ma T Y,Zhang P,Yan M.Effects of Dy71.5Fe28.5intergranular addition on the microstructure and the corrosion resistance of Nd-Fe-B sintered magnets[J].J.Magn.Magn.Mater.,2015,384:133.