Abstract
Resistance measurements during direct heating of Fe80B20 amorphous alloys indicate phase changes occur at 395, 500, 720 and 840° C. Samples heated to these temperatures, and maintained for five minutes in a neutral atmosphere, show that a hardness maximum occurs at the crystallization temperature of 395° C and that annealing at 500° C produces a material with the same hardness. Above 500° C the microhardness is seen to drop below that of the amorphous alloy. Saturation magnetization measurements show a steady increase following each anneal, up to a temperature of 720° C, and the rate of increase is seen to drop in the range of 720 to 840° C. X-ray diffraction studies show that only a small fraction of the matrix is crystallized following the anneal at 395° C and the transformed phases are α-Fe and Fe3B. Following annealing at 500° C, an increased proportion of α-Fe and Fe3B are observed with complete crystallinity while samples heattreated at 720° C are seen to consist of a three-phase mixture of α-Fe, Fe23B6 and Fe2B. Annealing at 840° C is seen to produce an equilibrium phase mixture of α-Fe and Fe2B phases. Only in the sample annealed at 395° C is a fraction of the amorphous phase seen to persist, indicating that a 5 min anneal is not sufficient, at this temperature, to induce complete crystallization. These structural features are corroborated by field ion microscope analyses, made at liquid nitrogen temperature in a medium of pure neon, and scanning electron microscopy, and are also consistent with our earlier study involving the isothermal annealing, for various times, of Fe80B20 alloy at 780° C.
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R. E. Maringer and C. E. Mobley, J. Vac. Sci. Technol. 11 (1974) 1067.
P. Chaudhary, B. C. Giessen and D. Turnbull, Sci. Amer. 242 (1980) 98.
O. T. Inal, L. Keller and F. G. Yost, J Mater. Sci. 15 (1980) 1947.
L. A. Davis, R. Ray, C. P. Chou and R. C. O'Handley, Scripta Met. 10 (1976) 541.
M. M. Karnowsky, J. Mater. Sci. 13 (1978) 2339.
U. Herold and U. Koster, Proceedings of the 3rd International Conference on Rapidly Quenched Metals, Brighton, July, 1978, Vol. II, p. 281.
U. Koster and U. Herold, Scripta Met. 12 (1978) 75.
U. Herold and U. Koster, Z. Metallkde. 69 (1978) 326.
J. L. Walter, S. F. Bartram and R. R. Russell, Met. Trans. A 9A (1978) 803.
H. Franke, U. Herold, U. Koster and M. Rosenberg, Proceedings of the 3rd International Conference on Rapidly Quenched Metals, Brighton, July, 1978, Vol. I, p. 155.
O. T. Inal and L. E. Murr, J. Appl. Phys. 49 (1978) 2427.
A. R. Stokes, Proc. Phys. Soc. Lond. 61 (1948) 382.
B. E. Warren, “X-ray Diffraction” (Addison-Wesley Pub. Co., New York, 1969).
K. P. Mizgalski, O. T. Inal, F. G. Yost and M. M. Karnowsky, unpublished work, 1981.
H. Fujita and K. Hashimoto, Mater. Sci. Eng. 45 (1980) 221.
B. D. Cullity, “Elements of X-ray Diffraction”, 2nd Edn (Addison Wesley Pub. Co., New York, 1978).
R. G. Wyckoff, “Crystal Structures”, 2nd Edn (Wiley-Interscience, New York, 1964).
F. M. Norman, H. Longsdale and K. Longsdale, “International Tables for X-ray Crystallography” Vol. 1 (Kynock Press, Birmingham, 1952).
F. E. Luborsky, Mater. Sci. Eng. 28 (1977) 129.
F. E. Luborsky, P. G. Frischmann and L. A. Johnson, J. Magnetism and Magnetic Mater. 8 (1978) 318.
R. M. Bozorth, “Ferromagnetism” (Van Nostrand Inc., New York, 1951) p. 224.
A. Taylor and B. J. Kagle, “Crystallographic Data on Metal and Alloy Structures” (Dover Publications Inc., New York, 1963) p. 195.
R. M. Bozorth, “Ferromagnetism” (Van Nostrand Inc., New York, 1951) p. 867.
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Inal, O.T., Robino, C.V., Keller, L. et al. Annealing behaviour of amorphous Fe80B20 on continuous heating. J Mater Sci 16, 3183–3193 (1981). https://doi.org/10.1007/BF00540327
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DOI: https://doi.org/10.1007/BF00540327