Design and fabrication of sintered Nd-Fe-B magnets with a low temperature coefficient of intrinsic coercivity

• Published in: Science of sintering 2009, Vol.41 (1), p.91-99
• Main Authors: Cui, X.G., Yan, M., Ma, T.Y., Luo, W., Tu, S.J.
• Format: Article
• Language: English
• Subjects: analysis of influencing factors; low temperature coefficient β; magnetic properties; sintered Nd-Fe-B magnets
• ISSN: 0350-820X; 1820-7413
• DOI: 10.2298/SOS0901091C

To decrease the temperature coefficients of sintered Nd-Fe-B magnets, the influencing factors on temperature coefficients, especially the reversible temperature coefficient ? of intrinsic coercivity Hcj, were analyzed. The results showed that the absolute value of ? decreased with increasing Hcj and also the ratio of microstructure parameter c to Neff, indicating that the increase of magnetocrystalline anisotropy field HA and c/Neff can effectively decrease the absolute value of ?. On the basis of this analysis, a sintered Nd-Fe-B magnet with a low temperature coefficient of Hcj was fabricated through composition design, and the value of ? was only -0.385%/?C in the temperature interval of 20-150?C. U cilju smanjenja temperaturnih koeficijenata sinterovanih Nd-Fe-B magneta analizirani su faktori uticaja na temperaturne koeficijente, narocito reverzibilni temperaturni koeficijent ? unutrasnje koercitivne sile Hcj. rezultati su pokazali da se apsolutna vrednost ? smanjila sa povecanjem Hcj kao i odnos mikrostrukturnih parametara c u Neff ukazujuci na to da povecanje magnetokristalnog anizotropnog polja HA i c/Neff mogu da efektivno smanje apsolutnu vrednost ?. Na osnovu ove analize proizveden je sinterovani Nd-Fe-B magnet sa niskotemperaturnim koeficijentom Hcj pri cemu je vrednost ? bila samo -0.385%/?C u temperaturnom intervalu 20-150?C.