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Microstructure of Cr2O3 coatings on steel and the effect of silicon

Published online by Cambridge University Press:  03 March 2011

M. Van den Burg  and
J.Th.M. De Hosson
M. Van den Burg
Affiliation:
Department of Applied Physics, University of Groningen, Nijenborgh 4, 99747AG Groningen, The Netherlands
J.Th.M. De Hosson
Affiliation:
Department of Applied Physics, University of Groningen, Nijenborgh 4, 99747AG Groningen, The Netherlands
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Abstract

This paper concentrates on the microstructural features of steel containing 22 wt. % Cr, coated with Cr2O3 by laser processing. It turned out that after laser coating the Cr2O3 powder has completely transformed to Fe0.3Cr2.7O4 having the tetragonal distorted spinel structure. Dispersed in the coating are metallic particles with composition FeCr and a bcc structure. The phases in the coating can be explained from the Fe-Cr-O equilibrium phase diagram with the assumption that complete phase equilibrium is reached in the liquid state but not during solidification. The two equilibrium phases, L0 and Lm, that exist in the molten state solidify as two independent liquids. Addition of Si to the ceramic material, either from the steel matrix or from the ceramic powder, results in a dendritic solidification structure of Cr3O4 dendrites and a Si-containing glassy phase. The dendrites are oriented vertically in the coating, resembling the columnar microstructure that is also observed in ZrO2 thermal barrier coatings. This structure contains fewer microcracks parallel to the interface resulting in a mechanically more stable ceramic coating.

Type
Articles
Information
Journal of Materials Research , Volume 9 , Issue 1 , January 1994 , pp. 142 - 150
Copyright
Copyright © Materials Research Society 1994

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References

REFERENCES

1“Sandvik SAF 2205”, UNS S31803, Sandviken, Sweden, S-l, 874-ENG (1989).Google Scholar
2JCPDS 12-559; Hilty, D. C., Forgeng, W. D., and Folkman, R. L., Trans. Am. Inst., Min. Metall. Eng. 203, 253 (1955).Google Scholar
3Metals Handbook, Metallography and Microstructures (American Society for Metals, Metals Park, OH, 1985), Vol. 9, p. 282.Google Scholar
4Philips APD 1700 system.Google Scholar
5Zhou, X. B. and De Hosson, J.Th.M., Acta Metall. 39, 2267 (1991).CrossRefGoogle Scholar
6Palache, C., Berman, H., and Frondel, C., Dana's System of Mineralogy (John Wiley, New York, 1946), Vol I, p. 712.Google Scholar
7Kingery, W. D., Introduction to Ceramics (John Wiley, New York, 1967), p. 58.Google Scholar
8Hansen, M. and Anderko, K., Constitution of Binary Alloys (McGraw-Hill, New York, 1958).CrossRefGoogle Scholar
9Kubaschewski, O., Iron-Binary Phase Diagrams (Springer-Verlag, Berlin, 1982), pp. 31-34 (Review).Google Scholar
10Raghavan, V., Phase Diagrams of Ternary Alloys, Part 5, Ternary Systems Containing Iron and Oxygen (Indian Institute of Metals, New Delhi, India, 1989), p. 89.Google Scholar
11Hilty, D. C., Forgeng, W. D., and Folkman, R. L., Trans. Am. Inst., Min. Metall. Eng. 203, 253 (1955).Google Scholar
12American Institute of Physics Handbook, Am. Inst. of Physics (McGraw-Hill, New York, 1972), pp. 2–24.Google Scholar
13Samsonor, G. V., The Oxide Handbook (Plenum, New York, 1973 pp. 34, 144.CrossRefGoogle Scholar
14Handbook of Chemistry and Physics, 52nd ed., E5 (CRC Press, Cleveland, OH, 1972).Google Scholar
15Fritscher, K. and Bunk, W., Density Graded TBC's Processed by EB-PVD, 1st Int. Symp. Functionally Gradient Material, Oct. 1990, Sendai, Japan.Google Scholar
16Mullins, W. and Sekerka, R., J. Appl. Phys. 34, 323 (1963).CrossRefGoogle Scholar
17Diffusion and Defect Data 4, 100 (1970).Google Scholar
18Muller-Krumbhaar, H. and Kurz, W., in Materials Science and Technology, edited by Cahn, R. W., Haasen, P., and Kram, E. J. (VCH Publishers, Inc., New York, 1991), Vol. 5, p. 553.Google Scholar