Flame-Assisted Flash Sintering of Ceramic Coatings for Heat Exchangers

ABSTRACT: nGimat proposes to develop a novel technique to sinter ceramic films deposited onto metallic substrates by combining two efficient and inexpensive techniques: flame sintering and field-assisted"flash"sintering. The creativeness of this approach lies in the concept to use a flame as both a heat source and a conductive medium. Compared to conventional thermal sintering, this new technique that we call Flame-Assisted Flash Sintering (FAFS) has the potential to reduce sintering temperatures and processing times, thereby leading to a substantial reduction in cost. Equally as important, the reduced processing temperatures will improve the performance of heat exchangers and solid-oxide fuel cells by avoiding high-temperature-induced effects such as film delamination and/or strain-induced defects. During Phase I, we will demonstrate the feasibility of FAFS to sinter a model ceramic material (such as 8% yitttria-stabalized zirconia) on austenitic stainless steel substrates up to 160 cm2 in area. In Phase II, we will scale up our FAFS processing equipment to accommodate full scale production levels and substrates>160 cm2, as well as experiment with other ceramic materials. The end result of the entire SBIR effort would be reduced costs for the Air Force and enhanced performance of components constructed via the FAFS technique. BENEFIT: The proposed flame-assisted flash sintering (FAFS) technique will reduce the sintering temperature and processing time of ceramic coatings on metallic substrates, thereby substantially lowering their manufacturing costs. Commercial applications of the research and development executed during this SBIR effort is not limited to ceramic heat exchangers, but also includes components used in solid-oxide fuel cells (SOFCs).