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Microstructure of atomized Ni3Al–B powder

Published online by Cambridge University Press:  31 January 2011

S. C. Huang
Affiliation:
General Electric Corporate Research and Development, P.O. Box 8, Scheneclady, New York 12301
A. M. Ritter
Affiliation:
General Electric Corporate Research and Development, P.O. Box 8, Scheneclady, New York 12301
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Abstract

The microstructure of boron-doped Ni3Al powder has been characterized by optical and transmission electron microscopy. Remarkable variations in the solidification morphology and phase reaction were observed as a function of powder size. The degree of boron segregation appeared to be reduced significantly, as the formation of M23B6 boride was suppressed in powder below ∼30 μm diameter. The primary solidification phase was disordered γ–Ni, which underwent a solid-state ordering transition to produce fine γ′–Ni3Al antiphase domains. A bi-modal distribution of domain sizes was observed due to Al segregation. The solidification morphology was dendritic for particles above ∼20 μm, and it changed to cellular below. In powder less than 40 μm diameter, second-phase particles of β–NiAl were found in intergranular regions, likely due to a metastable eutectic reaction of L ⇉ γ + β. The β phase was suppressed only for powder sizes below ∼2 μm. Judging from the tendency of second-phase formation, the Ni3Al–B powder appeared to cool slower than arc-hammer foil and melt-spun ribbon.

Type
Articles
Copyright
Copyright © Materials Research Society 1989

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References

REFERENCES

1Aoki, K. and Izumi, O., J. Jpn. Inst. Met. 43, 1190 (1979).CrossRefGoogle Scholar
2Liu, C. T., White, C. L., and Horton, J. A., Acta Metall. 33, 213 (1985).CrossRefGoogle Scholar
3Klarstrom, D. L., “Ni3Al VIM ESR Ingots,” presented at the Energy Conservation and Utilization Technology Workshop on “The Production and Fabrication of Ordered Intermetallic Alloys,” Oak Ridge National Laboratory, Oak Ridge, TN, September 25-26, 1984.Google Scholar
4Chang, K.-M., Huang, S.C., and Taub, A.I., in “Rapidly Solidified Metastable Materials,” edited by Kear, B.H. and Giessen, B.C. (Elsevier Science Publishing Co., New York, 1984), p. 401.Google Scholar
5Taub, A. I., Huang, S. C., and Chang, K.-M., Metall. Trans. A 15A, 399 (1984).CrossRefGoogle Scholar
6Huang, S. C., Taub, A. I., Chang, K.-M., Briant, C. L., and Hall, E. L., in Rapidly Quenched Metals, edited by Steeb, S. and Warlimont, H. (Elsevier Science Publishers B.V., Amsterdam, 1985), p. 1407.Google Scholar
7Chang, K.-M., Taub, A. I., and Huang, S. C., in High-Temperature Ordered Intermetallic Alloys, edited by Koch, C. C., Liu, C. T., and Stoloff, N. S. (Materials Research Society, Pittsburgh, PA, 1985), p. 335.Google Scholar
8Huang, S. C., Chang, K.-M., and Taub, A. I., in Rapidly Solidified Materials, edited by Lee, P. W. and Carbonara, R. S. (American Society for Metals, Metals Park, OH, 1985), p. 255.Google Scholar
9Chang, K.-M., Huang, S. C., and Taub, A. I., General Electric Technical Information Series, 86CRD202 (1986).Google Scholar
10Field, R. D. and Fraser, H. L., in Rapid Solidification Processing–Principles and Technologies, edited by Mehrabian, R., Kear, B.H., and Cohen, M. (Claitor's Publishing, Baton Rouge, LA, 1977), p. 270.Google Scholar
11Ritter, A. M. and Henry, M. F., J. Mat. Sci. 17, 73 (1982).CrossRefGoogle Scholar
12Koch, C.C., Horton, J.A., Liu, C.T., Cavin, O.B., and Scarbrough, J.O., in Rapid Solidification Processing–Principles and Technologies III, edited by Mehrabian, R. (National Bureau of Standards, Washington, DC, 1983), p. 264.Google Scholar
13Huang, S.C., Hall, E.L., Chang, K.-M., and Laforce, R.P., Metall. Trans. A 17A, 1685 (1986).CrossRefGoogle Scholar
14Mehrabian, R., in Rapid Solidification Processing–Principles and Technologies, edited by Mehrabian, R., Kear, B.H., and Cohen, M. (Claitor's Publishing, Baton Rouge, LA, 1977), p. 9.Google Scholar
15Hansen, M., Constitution of Binary Alloys (McGraw-Hill, New York, 1958), p. 119.Google Scholar
16Stadelmaier, H. H. and Fraker, A. C., Metall. 16, 212 (1962).Google Scholar
17Huang, S.C., Taub, A.I., and Chang, K.-M., Acta Metall. 32, 1703 (1984).CrossRefGoogle Scholar