"The Coupling Between Interfacial Charge and Mechanical Deformation at High Temperatures in Ceramics", supported by Basic Energy Sciences Division of the Department of Energy, under Dr. John Vetrano.

The Objective

Electric fields in Ceramics often influence the thermodynamic and kinetic behavior of defects, and thereby the rate of diffusional transport which controls stress driven phenomena such as superplasticity and sintering. The objective of this program is to uncover the fundamental mechanisms, often related to interfaces, underlying these effects.

The Approach

Two electrode experiments where dc electric fields are applied to specimens heated in the conventional way are leading to clear insights into how electrical field and applied stress influence densification and deformation, laying the foundation for fundamental understanding.

Key Findings

PDCs have more than three times the capacity for Li than graphite. The Sanchez-Jiminez publication given below shows that the Li is stored in the mixed bond, SiCO tetrahedra in the nanodomain structure of the PDCs.

Recent Publications on the effect of Electrical Fields on Densification:

Cologna, M., Prette, A.L.G. & Raj, R. 2011, "Flash-Sintering of Cubic Yttria-Stabilized Zirconia at 750 degrees C for Possible Use in SOFC Manufacturing", Journal of the American Ceramic Society, vol. 94, no. 2, pp. 316-319.
doi: 10.1111/j.1551-2916.2010.04267.x

Cologna, M. & Raj, R. 2011, "Surface Diffusion-Controlled Neck Growth Kinetics in Early Stage Sintering of Zirconia, with and without Applied DC Electrical Field", Journal of the American Ceramic Society, vol. 94, no. 2, pp. 391-395.
doi: 10.1111/j.1551-2916.2010.04088.x

Cologna, M., Rashkova, B. & Raj, R. 2010, "Flash Sintering of Nanograin Zirconia in < 5 s at 850 degrees C", Journal of the American Ceramic Society, vol. 93, no. 11, pp. 3556-3559.
doi: 10.1111/j.1551-2916.2010.04089.x

Ghosh, S., Chokshi, A.H., Lee, P. & Raj, R. 2009, "A Huge Effect of Weak dc Electrical Fields on Grain Growth in Zirconia", Journal of the American Ceramic Society, vol. 92, no. 8, pp. 1856-1859.
DOI: 10.1111/j.1551-2916.2009.03102.x

Prette, A.L.G., Cologna, M., Sglavo, V. & Raj, R. 2011, "Flash-sintering of Co2MnO4 spinet for solid oxide fuel cell applications", Journal of Power Sources, vol. 196, no. 4, pp. 2061-2065.

Yang, D., Raj, R. & Conrad, H. 2010, "Enhanced Sintering Rate of Zirconia (3Y-TZP) Through the Effect of a Weak dc Electric Field on Grain Growth", Journal of the American Ceramic Society, vol. 93, no. 10, pp. 2935-2937.
doi: 10.1111/j.1551-2916.2010.04089.x



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