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.
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References
K. Aoki and O. Izumi, J. Jpn. Inst. Met. 43, 1190 (1979).
C. T. Liu, C. L. White, and J. A. Horton, Acta Metall. 33, 213 (1985).
D. L. Klarstrom, “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.
K.-M. Chang, S. C. Huang, and A. I. Taub, in “Rapidly Solidified Meta-stable Materials,” edited by B. H. Kear and B. C. Giessen (Elsevier Science Publishing Co., New York, 1984), p. 401.
A. I. Taub, S. C. Huang, and K.-M. Chang, Metall. Trans. A 15A, 399 (1984).
S. C. Huang, A. I. Taub, K.-M. Chang, C. L. Briant, and E. L. Hall, in Rapidly Quenched Metals, edited by S. Steeb and H. Warlimont (Elsevier Science Publishers B. V., Amsterdam, 1985), p. 1407.
K.-M. Chang, A. I. Taub, and S. C. Huang, in High-Temperature Ordered Intermetallic Alloys, edited by C. C. Koch, C. T. Liu, and N. S. Stoloff (Materials Research Society, Pittsburgh, PA, 1985), p. 335.
S. C. Huang, K.-M. Chang, and A. I. Taub, in Rapidly Solidified Materials, edited by P. W. Lee and R. S. Carbonara (American Society for Metals, Metals Park, OH, 1985), p. 255.
K.-M. Chang, S. C. Huang, and A. I. Taub, General Electric Technical Information Series, 86CRD202 (1986).
R. D. Field and H. L. Fraser, in Rapid Solidification Processing—Principles and Technologies, edited by R. Mehrabian, B. H. Kear, and M. Cohen (Claitor’s Publishing, Baton Rouge, LA, 1977), p. 270.
A. M. Ritter and M. F. Henry, J. Mat. Sci. 17, 73 (1982).
C. C. Koch, J. A. Horton, C. T. Liu, O. B. Cavin, and J. O. Scarbrough, in Rapid Solidification Processing—Principles and Technologies III, edited by R. Mehrabian (National Bureau of Standards, Washington, DC, 1983), p. 264.
S. C. Huang, E. L. Hall, K.-M. Chang, and R. P. Laforce, Metall. Trans. A 17A, 1685 (1986).
R. Mehrabian, in Rapid Solidification Processing — Principles and Technologies, edited by R. Mehrabian, B. H. Kear, and M. Cohen (Claitor’s Publishing, Baton Rouge, LA, 1977), p. 9.
M. Hansen, Constitution of Binary Alloys (McGraw-Hill, New York, 1958), p. 119.
H. H. Stadelmaier and A. C. Fraker, Metall. 16, 212 (1962).
S. C. Huang, A. I. Taub, and K.-M. Chang, Acta Metall. 32, 1703 (1984).
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Huang, S.C., Ritter, A.M. Microstructure of atomized Ni3Al–B powder. Journal of Materials Research 4, 288–293 (1989). https://doi.org/10.1557/JMR.1989.0288
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DOI: https://doi.org/10.1557/JMR.1989.0288