Constrained and Non-Constrained Sintering of Plasma-Sprayed Zirconia Based Electrolytes for SOFCs

Abstract

Electrolyte layers for solid oxide fuel cells (SOFCs) consisting typically of yttria-stabilized zirconia were prepared using atmospheric plasma spraying in a first step and sintered in a second one. The influence of particle size on sintering kinetics and microstructure development was analyzed by comparison of nanostructured and conventional YSZ layers. Sintering of free-standing coatings differ significantly from that of coatings on substrates.

Low‐temperature stiffening of air plasma‐sprayed 7 wt% Y2O3‐stabilized ZrO2

“…There are various other studies which have shown the effect of sintering on reduction in porosity content and volume shrinkage. [30][31][32][33][34] Ilavsky's small angle scattering study suggests that certain types of pores and interfaces can undergo localized sintering even at 800°C to 900°C consistent with the knowledge of diffusion kinetics in YSZ. However, the implications of these low-temperature (<1000°C) microstructure changes on the elastic properties have not be studied, especially given that the coating has 8-9 times lower bending modulus than their completely dense counterparts largely due to the high porosity content and imperfect bonding between splats.…”

“…They found the surface area of cracks and voids kept decreasing beyond 600°C and almost 33% of surface area of voids and microcracks have been lost from as sprayed coating to 1000°C heat‐treated coating. There are various other studies which have shown the effect of sintering on reduction in porosity content and volume shrinkage …”

Dilatometry and DTA Analyses of a Sample Made of Ni Base Super Alloy with a ZrO₂/20%Y₂O₃ Ceramic Layer

“…The thermal expansion of the crystal lattice is the result of the increased vibration amplitude of the ions in the lattice nodes, caused by the temperature increase [3].…”