Abstract
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.
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References
J. J. Croat, J. F. Herbest, R. W. Lee and F. E. Pinkerton, Appl. Phys. Lett. 44 (1984) 148.
M. Sagawa, S. Fujimura, N. Togawa, H. Yamamoto and Y. Matsuura, J. Appl. Phys. 55 (1984) 2083.
J. D. Livingston, ibid. 57 (1985) 4137.
H. H. Stadelmaier and N. C. Liu, Mater. Lett. 4 (1986) 304.
G. C. Hadjipanayis and C. N. Christodoulou, J. Magn. Magn. Mater. 71 (1988) 235.
A. Fukuno and R. C. O'Handley, IEEE Trans. Magn. 26 (1990) 250.
C. N. Christodoulou and J. Schlup, J. Appl. Phys. 61 (1987) 3760.
J. Jacobson and A. Kim, ibid. 61 (1987) 3763.
Idem., IEEE Trans. Magn. 23 (1987) 2509.
JIS Society, “Data Book of Non-metallic Materials” (Heibunsha, Tokyo, 1985) p. 66.
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Osawa, Z., Higuchi, M. & Hinohara, S. Thermal oxidative deterioration and its prevention in Nd-Fe-B series plastic magnets. J Mater Sci 27, 5445–5448 (1992). https://doi.org/10.1007/BF00541604
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DOI: https://doi.org/10.1007/BF00541604