Skip to main content Accessibility help
×
Home

Temperature Gradients and Residual Porosity in Microwave Sintered Zinc Oxide

  • L. P. Martin (a1), D. Dadon (a1), M. Rosen (a1), A. Birman (a2), D. Gershon (a2), J. P. Calame (a2), B. Levush (a2) and Y. Carmel (a2)...

Abstract

ZnO samples were sintered in an overmoded 2.45 GHz microwave applicator. In-situ differential temperature measurements were made to allow comparison of surface and core temperatures during heating. At intermediate temperatures, near 600°C, the sample core was measured to be more than 250°C hotter than the sample surface. As the core temperature approached 1100°C, however, the difference between the surface and core temperatures diminished. Post-sintering scanning electron microscopy (SEM) showed spatial variations in the residual porosity which were consistent with the measured temperature differential. For samples sintered to intermediate temperatures, where large temperature differences persisted, there were significant gradients in the residual porosity. For samples sintered to higher temperatures, there was little residual porosity and no observable porosity gradient. Local density versus temperature behavior was obtained by correlating porosity levels measured from the micrographs with temperature measurements made during sintering. These data demonstrate a significantly lower activation energy for microwave sintering than for conventional sintering.

Copyright

References

Hide All
1. Several articles in MRS Bull., 18 [11], (1993).
2. Johnson, D. L., in Ceramic Transactions, Vol.21, Microwaves: Theory and Application in Materials Processing, Clark, D. E., Gac, F. D., and Sutton, W. H. eds. (American Ceramic Society, Westerville, OH, 1991), pp. 1728.
3. Clark, D. E. and Folz, D. C., in, pp. 2934.
4. Iskander, M. F., Andrade, O., Vikar, A., Kimrey, H., Smith, R., Lamoreaux, S., Cheng, C, Tanner, C. and Mhta, K., in, pp. 3548.
5. De, A., Ahmad, I., Whitney, E. D. and Clark, D. E., in, pp. 319328.
6. De, A., Ahmad, I., Whitney, E. Dow and Clark, D. E., in Microwave Processing of Materials HI, Snyder, W. B. Jr., Sutton, W.H., Iskander, M. F. and Johnson, D. L., eds. (Materials Research Society, Pittsburgh, PA, 1991), pp. 283288.
7. Hilliard, J. E. in Quantitative Microscopy, DeHoff, R. T. and Rhines, F. N., eds. (McGraw Hill, Inc., New York, 1968), pp. 4554.
8. Birman, A., Levush, B., Carmel, Y., Gershon, D., Dadon, D., Martin, L.P. and Rosen, M., in Ceramic Transactions, Vol.59, Microwaves: Theory and Application in Materials Processing III, Clark, D. E., Folz, D. C., Oda, S. J. and Silberglitt, R. eds. (American Ceramic Society, Westerville, OH, 1991), pp.30 5 - 312.
9. Birman, A., Gershon, D., Calame, J., Carmel, Y., Levush, B., Bykov, Yu. V., Eremeev, A. G., Holoptsev, V. V., Semenov, V. E., Dadon, D., Martin, L. P., Rosen, M. and Hutcheon, R., submitted to J. Appl. Phys. (1996).
10. Martin, L.P., Dadon, D., Gershon, D., Levush, B., Carmel, Y. and Rosen, M., in Ceramic Transactions, Vol.59, Microwaves: Theory and Application in Materials Processing III, Clark, D. E., Folz, D. C., Oda, S. J. and R. Silberglitt eds. (American Ceramic Society, Westerville, OH, 1991), pp. 39 9 - 406.
11. Johnson, D. L., J. Appl. Phys., 40, 192200 (1969).
12. Young, W. S. and Cutler, I. B., J. Am. Ceram. Soc., 53, 659663 (1970).
13. Woolfrey, J. L. and Bannister, M. J., J. Am. Ceram. Soc., 55, 390394 (1970).
14. Wang, J. and Raj, R., J. Am. Ceram. Soc., 73, 11721175 (1990).
15. Bagley, R.D., Cutler, I.B., and Johnson, D.L., J. Am. Ceram. Soc., 53, 136141 (1970).
16. Samuels, J. and Brandon, J. R., J. Mat. Sci., 27, 32593265 (1992).
17. Dadon, D., Martin, L. P., Rosen, M., Birman, A., Gershon, D., Calame, J. P., Levush, B. and Carmel, Y., submitted to J. Mat. Sci. and Proc. (1995).
18. Bannister, M. J., J. Am. Ceram. Soc., 51, 548553 (1968).
19. Gupta, T. K. and Coble, R.L., J. Am. Ceram. Soc., 51, 521525 (1968).
20. Dutta, S. K. and Spriggs, R. M., Mater. Res. Bull., 4, 797806 (1969).
21. Janney, M. and Kimrey, H., Mat. Res. Symp. Proc., 189, 215226 (1990).
22. Rybakov, K.I. and Semenov, V.E., Phys. Rev. B, 52, 30303033 (1995).
23. Freeman, S. A., Booske, J. H. and Cooper, R. F., Phys. Rev. Lett., 74, 20422045 (1995).

Related content

Powered by UNSILO

Temperature Gradients and Residual Porosity in Microwave Sintered Zinc Oxide

  • L. P. Martin (a1), D. Dadon (a1), M. Rosen (a1), A. Birman (a2), D. Gershon (a2), J. P. Calame (a2), B. Levush (a2) and Y. Carmel (a2)...

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.