Effects of co-sintering in self-standing CGO/YSZ and CGO/ScYSZ dense bi-layers
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Viscoelastic properties and sintering mechanisms of tape-casted gadolinium-doped ceria (CGO), yttrium-stabilized zirconia (YSZ), and scandium–yttrium-stabilized zirconia (ScYSZ) are characterized in order to investigate the reciprocal thermo-mechanical compatibility when arranged as a self-standing bi-layered electrolyte system. The combined use of thermo-mechanical analysis, optical dilatometry, and scanning electron microscopy ensures a systematic characterization of both the individual layers and CGO/YSZ and CGO/ScYSZ bi-layered laminates. The results of the co-firing process of the bi-layers are critical due to the mismatch of thermo-mechanical and sintering properties among the materials. Despite the better sinteractivity of ScYSZ, the self-standing CGO/ScYSZ bi-layer presents more challenges in terms of densification compared with the CGO/YSZ bi-layer. In particular, above 1200 °C, ScYSZ and CGO show residual porosity, and at higher sintering temperatures, above 1300 °C, full densification is completely inhibited by constrained sintering phenomena.
KeywordsShrinkage Rate Green Tape Zirconia Layer Shape Instability Viscosity Analysis
The authors would to acknowledge the EUDP (Danish Energy Agency) Project 64012-0225 “SOFC accelerated,” for sponsoring this research work. The authors are grateful to Tim Holgate for his help with the proofreading.
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