Skip to main content
Article
Studies of Microstructure and Magnetic Properties in Sintered Mixed Rare Earth (MRE) -Fe-B Magnets (MRE = Nd+La+Dy)
Journal of Applied Physics (2011)
  • W. Tang, Iowa State University
  • Y. Q. Wu, Iowa State University
  • K. W. Dennis, Iowa State University
  • N. T. Oster, Iowa State University
  • M. J. Kramer, Iowa State University
  • I. E. Anderson, Iowa State University
  • R. W. McCallum, Iowa State University
Abstract
Sintered [Nd(0.45)(La(r)Dy(1))(1/(r+1)*0.55)](2.6)Fe(14)B magnets (r = 1 to 3) were studied. Magnetic properties and microstructures of the magnets were investigated by magnetic measurements and electron microprobe analysis. The microstructure of magnets consists of a mixed rare-earth (MRE)(2)Fe(14)B (2: 14: 1) phase matrix having a grain size of similar to 8 mu m and a rare earth (RE)-rich grain boundary phase. The grain boundaries are rich in La and Nd but depleted in Dy, while the La, Nd, and Dy contents are constant across the 2: 14: 1 grains. The coercivity and temperature stability of magnets are improved with increasing Dy content. A (BH)(max) of 21.1 MGOe at room temperature is obtained in the magnet with r = 1. Temperature coefficients of alpha = -0.06 and beta = -0.48% degrees C were also obtained, which is comparable to those of Nd-based magnets with the best temperature stability. Unfortunately, the improvement of coercivity and its temperature coefficient is mainly achieved by adding greater amounts of Dy and DyF(3), which leads to low (BH)(max) values and high magnet costs.
Publication Date
April 1, 2011
Citation Information
W. Tang, Y. Q. Wu, K. W. Dennis, N. T. Oster, et al.. "Studies of Microstructure and Magnetic Properties in Sintered Mixed Rare Earth (MRE) -Fe-B Magnets (MRE = Nd+La+Dy)" Journal of Applied Physics Vol. 109 Iss. 7 (2011)
Available at: http://works.bepress.com/yaqiao_wu/2/