Strength evaluation of glass-ceramic composites containing yttria stabilized zirconia after thermal cycling

The effect of YSZ (yttria stabilized zirconia) on the thermal cycling stability of commercial glass ceramics powders as a solid oxide fuel cell (SOFC) sealant material is investigated. Four different composite sealants are prepared including 1, 3, 5 and 10 wt% of YSZ with respect to the total powders. A sealant without YSZ is also prepared as the base case for comparison. The fabrication of the sealant is achieved by using cost-effective tape casting routes. The samples are then placed between two metallic interconnectors and a high temperature glass forming process is performed. The mechanical performances are measured via tensile tests before and after a number of thermal cycles. The results indicate that the fracture strength is adversely affected by the amount of YSZ loading due to reduced glass ceramics powders in the composites. However, when the thermal cycling stability is the issue, the samples with YSZ show relatively small rate of decrease. Therefore, the addition of YSZ is found to be beneficial for improving the thermal cycle stability of glass-ceramics. The optimum YSZ content is determined to be 5 wt%, since these samples exhibit almost a stable mechanical performance after each thermal cycles considered in this study. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.