ISSN:
1573-4803
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Maschinenbau
Notizen:
Abstract The relationship between the annealing atmosphere and the magnetic properties of Fe78.5B13Si8.5 amorphous alloy has been studied, showing that annealing in nitrogen, argon, hydrogen and air significantly improved the iron loss of the amorphous ribbon, giving much better results than annealing in an H2 + H2O atmosphere. A boron-depletion zone with the alloy composition O to 3 mol % B and 9 to 11 mol% Si was detected by Auger electron spectroscopy under the oxide film formed during annealing in H2 + H2O. The iron crystalline phase is formed only on the ribbon surface after annealing in H2 + H2O. A mechanism is proposed explaining the deleterious effect of annealing in the H2 + H2O, whereby the H2O in this atmosphere selectively oxides boron in the amorphous alloy to form a B2O3 film and the boron-depletion zone, and the alloy in this zone is then crystallized into α-Fe. This surface crystalline layer induces out-of-plane magnetic anisotropy in the amorphous alloy ribbon (which was observed by transmission Mössbauer spectroscopy) and thus deterioration of the iron loss.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00580146
