Hostname: page-component-cd9895bd7-jkksz Total loading time: 0 Render date: 2024-12-23T11:56:22.414Z Has data issue: false hasContentIssue false
  • English
  • Français

Microencapsulation of silicon nitride particles with yttria and yttria-alumina precursors

Published online by Cambridge University Press:  31 January 2011

Ajay K. Garg  and
Lutgard C. De Jonghe
Ajay K. Garg
Affiliation:
Center for Advanced Materials, Materials and Chemical Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720
Lutgard C. De Jonghe
Affiliation:
Center for Advanced Materials, Materials and Chemical Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720
Get access

Abstract

Procedures are described to deposit uniform layers of yttria and yttria-alumina prccursors on fine powders and whiskers of silicon nitride. The coatings were produced by aging at elevated temperatures aqueous systems containing the silicon nitride core particles, yttrium and aluminum nitrates, and urea. Optimum concentrations of the core particles, in relation to the reactants, were established to promote surface deposition of the oxide precursors. Polymeric dispersants were used effectively to prevent agglomeration of the solids during the microencapsulation process. The morphology of the powders was characterized using scanning and transmission electron microscopy. The mechanisms for the formation of the coated layers are discussed. A description is provided that allows qualitative assessment of the experimental factors that determine microencapsulation by a slurry method.

Type
Articles
Information
Journal of Materials Research , Volume 5 , Issue 1 , January 1990 , pp. 136 - 142
Copyright
Copyright © Materials Research Society 1990

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 Sparks, R. E., in Encyclopedia of Chemical Technology, edited by M. Grayson and D. Eckroth (John Wiley and Sons, 1981), Vol. 15, p. 470.Google Scholar
2 Garg, A. and Matijevié, E., Langmuir 4, 38 (1988).CrossRefGoogle Scholar
3 Willkens, C. A. and Corbin, N. D., Proc. 25th Automotive Technology Development Contractors Coordination Meeting (1987).Google Scholar
4 Singh, R. N. and Brun, M. K, Adv. Ceram. Mater. 3 (3), 235 (1988).CrossRefGoogle Scholar
5 Schoenlein, L. H., Jones, R. H., Henager, C. H., Schilling, C. H., and Gac, F., Proc. Materials Research Society Spring 1988 Meeting (1988).Google Scholar
6 Bender, B., Shadwell, D., Bulik, C., Incorvati, L., and Lewis, D., III Ceram. Bull. 65 (2), 363 (1986).Google Scholar
7 Zern, C. A., Lehman, R. L., Greenhut, V. A., and Watchman, J. B., Jr., American Ceramic Society Annual Convention, Talk 59-B-88 (1988).Google Scholar
8 Cannon, P., J. Metals, 10–14 (1988).CrossRefGoogle Scholar
9 Mortensen, A., Cornie, J. A., and Flemings, M. C., J. Metals, 12–19 (1988).CrossRefGoogle Scholar
10 Naslain, R., Pailler, R., and Martineau, P., in Physical Chemistry of the Solid State: Application to Metals and Their Compounds, edited by Lacombe, P. (Elsevier Science Publishers B.V., Amsterdam, 1984), p. 481.Google Scholar
11 Chou, T.W., Kelly, A., and Okura, A.,Composites 16 (3), 187 (1985).CrossRefGoogle Scholar
12 Pai, B. C. and Rohatgi, P. K., Mater. Sci. Eng. 21, 161 (1975).CrossRefGoogle Scholar
13 Tokisue, H. and Abbaschian, G.J., Mater. Sci. Eng. 34, 75–78 (1978).CrossRefGoogle Scholar
14 Gopakumar, K., Murali, T. P., and Rohatgi, P. K., J. Mater. Sci. 17, 1041 (1982).CrossRefGoogle Scholar
15 D, . and Rohatgi, P. K., J. Mater. Sci. 16, 1599 (1981).Google Scholar
16 Banerji, A., Rohatgi, P. K., and Reif, W., Metallwissenschaft Technik 38 (7), 656 (1984).Google Scholar
17 Chaklader, A.C.D. and Linger, K. R., Composites, 239–243, October 1976.CrossRefGoogle Scholar
18 Akinc, M. and Sordelet, D., Adv. Ceram. Mater. 2 (3A), 232 (1987).CrossRefGoogle Scholar
19 LaMer, V. K. and Dinegar, R. H., J. Am. Chem. Soc. 72 (11), 4847 (1950).CrossRefGoogle Scholar
20 Gherardi, P. and Matijević, E., J. Colloid Interface Sci. 109 (1), 57 (1986).CrossRefGoogle Scholar
21 Ishikawa, T. and Matijević, E., Langmuir 4, 26 (1988).CrossRefGoogle Scholar
22 Blendell, J. E., Bowen, H. K., and Coble, R. L., Am. Ceram. Soc.Bull. 63 (6), 797 (1984).Google Scholar
23 Kratohvil, S. and Matijević, E., Adv. Ceram. Mater. 2 (4), 798–803 (1987).CrossRefGoogle Scholar
24 Garg, A. and Matijević, E., J. Colloid Interface Sci. (in press).Google Scholar
25 Kapolnek, D. and De Jonghe, L. C., unpublished results, 1988.Google Scholar
26 Shaw, T. M., J. Am. Ceram. Soc. 69 (1), 27 (1986).CrossRefGoogle Scholar