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A thermogravimetric study of the oxidative growth of Al2O3/Al alloy composites

Published online by Cambridge University Press:  31 January 2011

K.C. Vlach ,
O. Salas ,
H. Ni ,
V. Jayaram ,
C.G. Levi  and
R. Mehrabian
K.C. Vlach
Affiliation:
Assistant Research Engineer, University of California, Santa Barbara, California 93106
O. Salas
Affiliation:
Graduate Student Researcher, University of California, Santa Barbara, California 93106
H. Ni
Affiliation:
Assistant Specialist, University of California, Santa Barbara, California 93106
V. Jayaram
Affiliation:
Assistant Professor, Indian Institute of Science, Bangalore, India
C.G. Levi
Affiliation:
Associate Professor of Materials and Mechanical Engineering, University of California, Santa Barbara, California 93106
R. Mehrabian
Affiliation:
President, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213
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Abstract

The oxidation of liquid Al–Mg–Si alloys at 900–1400 °C was studied by thermogravimetric analysis (TGA). The development of a semi-protective surface layer of MgO/MgAl2O4 allows the continuous formation of an Al2O3-matrix composite containing an interpenetrating network of metal microchannels at 1000–1350 °C. An initial incubation period precedes bulk oxidation, wherein Al2O3 grows from a near-surface alloy layer by reaction of oxygen supplied by the dissolution of the surface oxides and Al supplied from a bulk alloy reservoir through the microchannel network. The typical oxidation rate during bulk growth displays an initial acceleration followed by a parabolic deceleration in a regime apparently limited by Al transport to the near-surface layer. Both regimes may be influenced by the Si content in this layer, which rises due to preferential Al and Mg oxidation. The growth rates increase with temperature to a maximum at ∼1300 °C, with a nominal activation energy of 270 kJ/mole for an Al−2.85 wt. % Mg−5.4 wt. % Si alloy in O2 at furnace temperatures of 1000–1300 °C. An oscillatory rate regime observed at 1000–1075 °C resulted in a banded structure of varying Al2O3-to-metal volume fraction.

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Articles
Information
Journal of Materials Research , Volume 6 , Issue 9 , September 1991 , pp. 1982 - 1995
Copyright
Copyright © Materials Research Society 1991

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References

1.Newkirk, M. S., Urquhart, A. W., Zwicker, H. R., and Breval, E., J. Mater. Res. 1, 81–89 (1986).CrossRefGoogle Scholar
2.Newkirk, M. S., Lesher, H. R., White, D. R., Kennedy, C. R., Urquhart, A. W., and Claar, T. D., Ceram. Eng. Sci. Proc. 8, 879–885 (1987).CrossRefGoogle Scholar
3. O. Salas, Ni, H., Jayaram, V., Vlach, K. C., Levi, C. G., and Mehrabian, R., J. Mater. Res. 6, 1964–1981 (1991).CrossRefGoogle Scholar
4.Nagelberg, A. S., Solid State Ionics 32/33, 783–788 (1989).CrossRefGoogle Scholar
5.Salas, O., Jayaram, V., Levi, C. G., and Mehrabian, R., submitted for publication to J. Am. Ceram. Soc. (1991).Google Scholar
6.Aghajanian, M. K., MacMillan, N. H., Kennedy, C. R., Luszcz, S. J., and Roy, R., J. Mater. Sci. 24, 658–670 (1989).CrossRefGoogle Scholar
7.Schmalzried, H. and Laqua, W., Oxid. Met. 15 (3/4), 339–353 (1981).CrossRefGoogle Scholar
8.Balicki, S., Prace Inst. Hutnic. 10, 208–213 (1958).Google Scholar
9.Jones, C. F., Segall, R. L., Smart, R. St. C., and Turner, P. S., Philos. Mag. A 42, 267–270 (1970).Google Scholar
10.Turkdogan, E. T., Grieveson, P., and Darken, L. S., J. Phys. Chem. 67, 1647–54 (1963).CrossRefGoogle Scholar
11.Vlach, K. C., unpublished research.Google Scholar
12.Brennan, J. J. and Pask, J. A., J. Am. Ceram. Soc. 51, 569–573 (1968).CrossRefGoogle Scholar
13.Eustathopoulos, N., Joud, J. C., Desre, P., and Hicter, J. M., J. Mater. Sci. 9, 1233–1242 (1974).CrossRefGoogle Scholar
14.John, H. and Hausner, H., J. Mater. Sci. Lett. 5, 549–551 (1986).CrossRefGoogle Scholar
15.Weirauch, D. A. and Krafick, W. J., Metall. Trans. A 21A, 1745–1751 (1990).CrossRefGoogle Scholar
16.Smeltzer, W. W., J. Electrochem. Soc. 105, 67–71 (1958).CrossRefGoogle Scholar
17.Winterbottom, W. L. and Gilmour, G. A., J. Vac. Sci. Technol. 13, 634–643 (1976).CrossRefGoogle Scholar
18.Hidvegi, E. and Kovacs-Csetenyi, E., Mater. Sci. Eng. 27, 39–43 (1977).CrossRefGoogle Scholar
19.Weirauch, D. A., J. Mater. Res. 3, 729–739 (1988).CrossRefGoogle Scholar
20.Belitskus, D. L., Oxid. Met. 3, 313–317 (1971).CrossRefGoogle Scholar
21.Belitskus, D. L., Oxid. Met. 8, 303–307 (1974).CrossRefGoogle Scholar
22.Cochran, C. N., Belitskus, D. L., and Kinosz, D. L., Metall. Trans. B 8B, 323–332 (1977).CrossRefGoogle Scholar
23.Beruto, D., Rossi, P. F., and Searcy, A. W., J. Phys. Chem. 89, 1695–1699 (1985).CrossRefGoogle Scholar
24.Livey, D. T., Wanklyn, B. M., Hewitt, M., and Murray, P., Trans. Br. Ceram. Soc. 56, 217–236 (1957).Google Scholar
25.Drouzy, M. and Richard, M., Fonderie 29, 121–128 (1974).Google Scholar
26.Haginoya, I. and Fukusako, T., J. Jpn. Inst. Light Met. 24, 364 (1974), republished in English in Trans. Jpn. Inst. Met. 24, 613–619 (1983).CrossRefGoogle Scholar
27.Geiger, G. H. and Poirier, D. R., Transport Phenomena in Metallurgy (Addison-Wesley Publishing Co., Reading, MA, 1973), Chap. 11.Google Scholar
28.Rohsenow, W. M. and Hartnett, J. P., Handbook of Heat Transfer (McGraw-Hill Book Co., New York, 1973), Sec. 7.Google Scholar
29. JANAF Thermochemical Tables, 3rd ed, Part 1: J. Phys. Chem. Ref. Data 14, Suppl. No. 1, 156 (1985).Google Scholar