Glasses are used for sealing and joining materials in a myriad of technological applications such as vacuum technology, microelectronics and power electronics. Seals are also needed for new and more efficient energy producing devices such as solid oxide fuel cells (SOFCs) for conservation of limited natural resources for energy production. The seals for SOFCs function at very high temperatures and are susceptible to cracking in service. The research work is expected to develop a new class of glass and glass-composites that self-repair cracks or damage thereby providing long-life and cost-effective solutions to seals for SOFCs. The research also has potentials for enormous payoffs by (1) training students in invaluable technical and research skills applicable to both academia and industry, and (2) advance enhancing the institutional the resources of institution by the enhancement of existing facilities for the synthesis of glasses and glass-composites for high-technology applications.
TECHNICAL DETAILS: While glasses are promising for making seals for SOFCs, they suffer from cracking because of their inherent brittleness when exposed to thermal transients. Recently, a transformative concept of self-healing/self-repairable glasses as seals for SOFCs was discovered, which requires a fundamental understanding of the kinetics and mechanism of crack healing in glasses and glass-ceramic composites. Therefore, the primary focus of this research is a basic investigation of the crack-healing mechanism and kinetics in promising glass and glass-ceramic composites displaying self-repair in order to further advance this transformative concept of self-repairable seals for SOFCs. With such an understanding one can identify the crack-healing mechanism and be able to predict the healing time required for achieving self-repair. The approach involves the synthesis of dense glass and glass-ceramic composites containing a crystalline ceramic phase, and studying the morphological evolution of cracks upon healing and crack-healing kinetics. The approach to this crack-healing study involves creating cracks of controlled geometry using a Vickers microindenter and then determining the crack-healing kinetics via measuring the crack shape and crack length as a function of time at different temperatures. The research is novel and transformative because the results will be the first comprehensive study of the crack-healing behaviors of glasses and glass-ceramic composites useful as active self-repairable seals for SOFCs.
