Z Chen , Y Zhang , G.C Hadjipanayis , Q Chen , B Ma
{"title":"Refinement of α-Fe and its improvement on magnetic properties of melt-spun nanocomposite Pr2Fe14B/α-Fe magnets by low wheel speed spinning","authors":"Z Chen , Y Zhang , G.C Hadjipanayis , Q Chen , B Ma","doi":"10.1016/S0965-9773(99)00420-1","DOIUrl":null,"url":null,"abstract":"<div><p>Nanocomposite Pr<sub>2</sub>Fe<sub>14</sub><span>B/α-Fe magnets with uniform microstructure and enhanced magnetic properties have been synthesized by melt-spinning a Pr</span><sub>8</sub>Fe<sub>86</sub>B<sub>6</sub> alloy at low wheel speed range. Microstructural and magnetic studies showed that there is an optimum wheel speed (about 16.7 m/s) at which a uniform Pr<sub>2</sub>Fe<sub>14</sub>B/α-Fe structure with fine α-Fe grains (about 10 nm) is developed directly from the melt. Lower speed gives larger grains for both the 2:14:1 and α-Fe, while higher speed leads to the appearance of an amorphous phase which will result in a Pr<sub>2</sub>Fe<sub>14</sub>B/α-Fe structure with larger α-Fe grains after a subsequent crystallization annealing. Magnetic properties obtained under the optimum-quenching followed by a subsequent annealing are M<sub>s</sub> = 176.6 emu/g, M<sub>r</sub> = 118.2 emu/g, M<sub>r</sub>/M<sub>s</sub> = 0.67, H<sub>c</sub> = 5.4 kOe and (BH)<sub>m</sub><span> = 12.6 MGOe. The coercivity and energy product are about 20% higher than those obtained by crystallization of over-quenched samples due to the refinement of α-Fe size which leads to an enhanced exchange coupling between Pr</span><sub>2</sub>Fe<sub>14</sub>B and α-Fe.</p></div>","PeriodicalId":18878,"journal":{"name":"Nanostructured Materials","volume":"11 8","pages":"Pages 1285-1292"},"PeriodicalIF":0.0000,"publicationDate":"1999-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0965-9773(99)00420-1","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nanostructured Materials","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0965977399004201","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 2
Abstract
Nanocomposite Pr2Fe14B/α-Fe magnets with uniform microstructure and enhanced magnetic properties have been synthesized by melt-spinning a Pr8Fe86B6 alloy at low wheel speed range. Microstructural and magnetic studies showed that there is an optimum wheel speed (about 16.7 m/s) at which a uniform Pr2Fe14B/α-Fe structure with fine α-Fe grains (about 10 nm) is developed directly from the melt. Lower speed gives larger grains for both the 2:14:1 and α-Fe, while higher speed leads to the appearance of an amorphous phase which will result in a Pr2Fe14B/α-Fe structure with larger α-Fe grains after a subsequent crystallization annealing. Magnetic properties obtained under the optimum-quenching followed by a subsequent annealing are Ms = 176.6 emu/g, Mr = 118.2 emu/g, Mr/Ms = 0.67, Hc = 5.4 kOe and (BH)m = 12.6 MGOe. The coercivity and energy product are about 20% higher than those obtained by crystallization of over-quenched samples due to the refinement of α-Fe size which leads to an enhanced exchange coupling between Pr2Fe14B and α-Fe.