Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-13T01:58:54.919Z Has data issue: false hasContentIssue false

The initiation of spontaneous infiltration of alloys into carbon preforms in air

Published online by Cambridge University Press:  31 January 2011

X. F. Yang
Affiliation:
Materials Research and Education Center, 201 Ross Hall, Auburn University, Auburn, Alabama 36849
X. M. Xi
Affiliation:
Materials Research and Education Center, 201 Ross Hall, Auburn University, Auburn, Alabama 36849
L. M. Xiao
Affiliation:
Materials Research and Education Center, 201 Ross Hall, Auburn University, Auburn, Alabama 36849
Get access

Extract

It was found in a previous work that the Al–Si alloy could spontaneously infiltrate into carbon preforms in air. In this study, the initiation stage of the infiltration process was investigated in detail through two different infiltration experiments. In one experiment, carbon preforms were fully dipped into an alloy bath that was exposed to air, and in the other experiment a carbon preform was only partially dipped into an alloy bath that was protected with a flowing Ar or N2 gas. Experimental results have suggested that the initiation of infiltration is controlled by the pressure of oxidizing gases such as O2 or CO at the infiltration front and is not affected by the presence or absence of N2 gas. The critical pressure of oxidizing gases is estimated to be on the order of 10−4 atm for systems investigated in our experiments. An effective way to reduce the O2 or CO pressure is to flush a preform with nonoxidizing gases during or before infiltration, or to use an active metal to reduce the O2 pressure and thus the corresponding CO pressure.

Type
Articles
Copyright
Copyright © Materials Research Society 1998

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1.Yang, X. F. and Xi, X.M., J. Mater. Res. 10, 2415 (1995).CrossRefGoogle Scholar
2.Hillig, W. B., Ceram. Eng. Sci. Proc. 8, 834 (1987).CrossRefGoogle Scholar
3.Hillig, W. B., J.Am. Ceram. Soc. 71, C-96 (1988).Google Scholar
4.Hillig, W. B., Am. Ceram. Soc. Bull. 73, 56 (1994).Google Scholar
5.Ness, J.N. and Page, T. F., J. Mater. Sci. 21, 1377 (1986).CrossRefGoogle Scholar
6.Messner, R. P. and Chiang, Y.M., J. Am. Ceram. Soc. 73, 1193 (1990).CrossRefGoogle Scholar
7.Xi, X.M. and Yang, X. F., J. Am. Ceram. Soc. 79, 102 (1996).CrossRefGoogle Scholar
8.Xi, X.M., Xiao, L.M., and Yang, X. F., J. Mater. Res. 11, 1037 (1996).CrossRefGoogle Scholar
9.Yang, X. F. and Xi, X.M., J. Mater. Sci 30, 5099 (1995).CrossRefGoogle Scholar
10.Xi, X.M., Xiao, L.M., and Yang, X. F., Adv. Composite Mater. 5, 283 (1996).CrossRefGoogle Scholar