Journal of Materials Science

, Volume 27, Issue 20, pp 5445–5448 | Cite as

Thermal oxidative deterioration and its prevention in Nd-Fe-B series plastic magnets

  • Z. Osawa
  • M. Higuchi
  • S. Hinohara


Thermal oxidative behaviour of Nd-Fe-B series magnetic powders and effects of surface treatment of the powders with polyacrylonitrile (PAN) and coupling agents on thermal oxidation were examined by thermal analysis (thermogravimetric and differential thermal). In addition, plastic magnets were prepared with magnetic powders (untreated, pre-oxidized and PAN treated) and nylon 12 and their magnetic properties were compared. Oxidation of the magnetic powders easily occurred and weight gain started at ∼ 100 °C and suddenly increased at ∼ 280 °C. Thermal oxidation of the magnetic powders greatly deteriorated the magnetic properties of the plastic magnets. The surface treatment of the powders was found to be effective for the prevention of the oxidation, especially when treated with PAN, and provided thermally stable plastic magnets.


Oxidation Polymer Weight Gain Magnetic Property Thermal Analysis 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    J. J. Croat, J. F. Herbest, R. W. Lee and F. E. Pinkerton, Appl. Phys. Lett. 44 (1984) 148.CrossRefGoogle Scholar
  2. 2.
    M. Sagawa, S. Fujimura, N. Togawa, H. Yamamoto and Y. Matsuura, J. Appl. Phys. 55 (1984) 2083.CrossRefGoogle Scholar
  3. 3.
    J. D. Livingston, ibid. 57 (1985) 4137.CrossRefGoogle Scholar
  4. 4.
    H. H. Stadelmaier and N. C. Liu, Mater. Lett. 4 (1986) 304.CrossRefGoogle Scholar
  5. 5.
    G. C. Hadjipanayis and C. N. Christodoulou, J. Magn. Magn. Mater. 71 (1988) 235.CrossRefGoogle Scholar
  6. 6.
    A. Fukuno and R. C. O'Handley, IEEE Trans. Magn. 26 (1990) 250.CrossRefGoogle Scholar
  7. 7.
    C. N. Christodoulou and J. Schlup, J. Appl. Phys. 61 (1987) 3760.CrossRefGoogle Scholar
  8. 8.
    J. Jacobson and A. Kim, ibid. 61 (1987) 3763.CrossRefGoogle Scholar
  9. 9.
    Idem., IEEE Trans. Magn. 23 (1987) 2509.CrossRefGoogle Scholar
  10. 10.
    JIS Society, “Data Book of Non-metallic Materials” (Heibunsha, Tokyo, 1985) p. 66.Google Scholar

Copyright information

© Chapman & Hall 1992

Authors and Affiliations

  • Z. Osawa
    • 1
  • M. Higuchi
    • 1
  • S. Hinohara
    • 2
  1. 1.Faculty of EngineeringGunma UniversityGunmaJapan
  2. 2.Dai-Chi Kasei Co. LtdTochigiJapan

Personalised recommendations