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Effect of High Heating Rates on Microstructure of Alumina and Aluminum Titanate Ceramics

Published online by Cambridge University Press:  02 July 2020

Lia A. Stanciu
Affiliation:
Department of Chemical Engineering and Materials Science, University of California, Davis, CA , 95616
Joanna R. Groza
Affiliation:
Department of Chemical Engineering and Materials Science, University of California, Davis, CA , 95616
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Abstract

In conventional sintering, high heating rates are often used to enhance densification and reduce grain growth. The essence of this concept is to use fast heating rates to favor densification instead of grain growth, if the activation energy for densification is greater than that for grain growth. At low temperatures, surface diffusion is the most effective sintering mechanism but is associated with grain coarsening. Therefore, a high heating rate may take the system for densification at high temperatures before surface diffusion causes grain growth and decreases the sintering driving force. Field activated sintering technique (FAST) is a newly developed sintering method, which applies an external electrical field to enhance densification. The method applies pulsed and continuous current to powders subject to a modest pressure (< 100 MPa). Electrical current application enables fast heating rates. The sintering cycles are very short, typically less than 10 minutes for full densification.

Type
Novel Microscopy Assisted Ceramic Developments in Materials Scienceand Nanotechnology (Organized by P. Gai and J. Lee)
Copyright
Copyright © Microscopy Society of America 2001

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References

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