Abstract
The thermal stability and coarsening of nanostructures is of both scientific interest and of engineering significance in order to produce thermally stable nanomaterials. Real time observations were carried out using ultra high vacuum (UHV) in situ TEM to investigate the coarsening process of a highly modulated nanolamellar structure obtained by crystallization of a Co based Co65Si15B14Fe4Ni2 amorphous magnetic alloy. The coarsening process consisted of three steps: (a) precipitation of spherical fine precipitates; (b) continuous coarsening of the nanolamellar structure at the surface and precipitation at the grain boundaries; and (c) formation of a stable multiphase structure. Due to surface effects, continuous coarsening of nanolamellar structure was observed during in-situ annealing; this mechanism was different from that of the coarsening process found during conventional annealing. Discontinuous coarsening from grain boundaries, which dominates the coarsening process in the conventional annealing of bulk sample, also occurred in in-situ annealing of thin sample. The driving force for coarsening of the nanolamellar structure from interlamellar interfaces, grain boundaries and surfaces is discussed.
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References
H. GLEITER, Acta Mater. 48 (2000) 1.
J. W. MARTIN, R. D. DOHERTY and B. CANTOR, “Stability of Microstructure in Metallic Systems”, 2nd ed. (Cambridge University Press, 1997) p. 219.
J. C. ZHAO and M. R. NOTIS, Acta Mater. 46 (1998) 4203.
G. SHARMA, R. V. RAMANUJAN and G. P. TIWARI, ibid. 48 (2000) 875.
S. VEPREK and M. JILEK, Vacuum 67 (2002) 443.
A. L. GREER, in Proc. 22nd Risø Inter. Symp. Mater. Sci.: Science of Metastable and Nanocrystalline Alloys, Structure, Properties and Modeling, edited by A. R. Dinesen, M. Eldrup, D. Juul Jensen, S. Linderoth, T. B. Pedersen and N. H. Pryds, A. Schrøder Pedersen and J. A. Wert, (Denmark, 2001) p. 461.
J. LEE, F. ZHOU and K. H. CHUNG, Metall. Mater. Trans. A 32 (2001) 3109.
F. LIU and R. KIRCHHEIM, J. Cryst. Growth 264 (2004) 385.
H. TANIMOTO, P. FARBER, R. WÜRSCHUM, R. Z. VALIEV and H. E. SCHAEFER, Nanostruct. Mater. 12 (1999) 681.
H. F. LI and R. V. RAMANUJAN, Intermetallics 12 (2004) 803.
Idem., Mater. Sci. Eng. A 375–377 (2004) 1087.
N. NISHIYAMA, M. MATSUSHITA and A. INOUE, Scripta Mater. 44 (2001) 1261.
L. TAN and W. C. CRONE, ibid. 50 (2004) 819.
S. X. ZHOU, Y. G. WANG, J. H. ULVENSØEN and R. HØIER, IEEE Trans. Magn. 30 (1994) 4815.
F. ZHOU, K. Y. HE and K. LU, Nanostruct. Mater. 9 (1997) 387.
S. C. BYEON, C. K. KIM, K. S. HONG and R. C. O’HANDLEY, Mater. Sci. Eng. B 56 (1999) 58.
R. V. RAMANUJAN, P. J. MAZIASZ and C. T. LIU, Acta Mater. 44 (1996) 2611.
P. VILLARS, A. PRINCE and H. OKAMOTO, “Handbook of Ternary Alloy Phase Diagrams” (computer file) (ASM international, Materials Park, 1997).
D. A. PORTER and K. E. EASTERLING, “Phase Transformations in Metals and Alloys”, 2nd ed. (Chapman & Hall, 1992).
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Li, H.F., Foo, Y.L. & Ramanujan, R.V. In-situ TEM observations of the coarsening of a nanolamellar structure in a cobalt based magnetic alloy. J Mater Sci 40, 1901–1907 (2005). https://doi.org/10.1007/s10853-005-1209-3
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DOI: https://doi.org/10.1007/s10853-005-1209-3