The role of Nb in the nanocrystallization of amorphous Fe-Si-B-Nb alloys
- Ehime Univ., Matsuyama (Japan). Dept. of Materials Science and Engineering
The aging behavior of amorphous Fe{sub 84{minus}x}Si{sub 6}B{sub 10}Nb{sub x} alloys was investigated using differential scanning calorimetry (DSC), transmission electron microscopy, and high-frequency magnetic measurements. A marked change in the peak morphology was observed on the DSC curve for the alloys containing more than 3 at.% Nb. The right side of the first exothermic peak extended to the higher temperature side, while the second exothermic peak was drastically reduced in its intensity. After aging for 3.6 ks in the first exothermic temperature ranges, all the alloys with a Nb content up to 6 at.% were composed of a mixed structure of the {alpha}-Fe phase and an amorphous matrix; however, the addition of more than 3 at.% Nb caused a significant grain refinement of the crystallization-induced {alpha}-Fe particles. Furthermore, the low-temperature aging produced a notable increase in the effective permeability only for the alloys containing more than 3 at.% Nb, even though the amorphous phase remained unchanged without crystallization. Based on these results, the mechanism of nanocrystallization was reasonably explained as being related to a change in the amorphous structure which occurs in the vicinity of 2--3 at.% Nb.
- OSTI ID:
- 616189
- Journal Information:
- Acta Materialia, Vol. 46, Issue 2; Other Information: PBD: 5 Jan 1998
- Country of Publication:
- United States
- Language:
- English
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