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Although various additive manufacturing techniques are used intensively to mold materials for solid oxide fuel cell (SOFC) applications, 3D printing has not been applied to obtain sealants which are crucial components for SOFC stacking. It is essential to develop different methods for molding sealing products based on glasses and glass-ceramics which are the most promising materials for SOFC stacking. This study reveals the potential of fused deposition modeling (FDM) for the production of complex shape objects for the sealing of tubular SOFC in the example of the composition based on thermoplastic, thermoplastic elastomer, oil, and a filler (glass sealant). The highest filler content in the mixture is 63 wt %. Two aluminosilicate sealants of different compositions are used as the filler and the printed products are successfully applied for tubular supporting anode|sealant|steel joints. • FDM is successfully used to obtain products for tubular SOFC sealing. • Bubbles in the sealant volume do not violate the sealing. • Tubular supporting anode|sealant|steel joints are prepared using printed products. [ABSTRACT FROM AUTHOR]

A low leakage rate sealant of 10 wt% ZrO 2 -added CaO–K 2 O–Na 2 O–BaO silicate glass for SOFC has been studied. The structure of the sealant is stable at high temperatures with leakage rates less than 10−4 sccm∙cm−1, and no crystal except for ZrO 2 is found in XRD analysis after heating at 800 °C for 100 h. ZrO 2 is distributed in the glass matrix and plays a supporting role in avoiding over-softening at operating temperature. Good compatibility in both oxidizing and reducing atmospheres between the sealant and SUS430 interconnect was proved by SEM at 750 °C for 100 h. A fully coupled 3D Multiphysics button SOFC is constructed for mechanical analyses. The results show that the increase of ZrO 2 in the sealant will decrease the stress and displacement in the SOFC. Besides, the width of the sealant also affects the stress value and distribution. The results show that GZ10 is a competitive sealing material compared with other ZrO 2 -added sealants. [ABSTRACT FROM AUTHOR]

The behaviour of the promising glass sealant 54.4SiO 2 -13.7Na 2 O-1.7K 2 O-5.0CaO-12.4MgO-0.6Y 2 O 3 -11.3Al 2 O 3 -0.9B 2 O 3 for solid oxide fuel cells (SOFCs) under SOFC operating conditions was studied. First, the kinetics of the crystallisation processes at the operating temperature (850 °C) was discussed (maximum exposure time of 1000 h), and the effect of crystallisation on the coefficient of thermal expansion (CTE) of the sealant was studied. Furthermore, the degradation processes at the interface of the glass sealant and functional SOFC materials (Crofer 22 APU, YSZ, and NiO(Ni)-YSZ) during exposure to 850 °C in oxidising and reducing atmospheres for 500 h were studied. The tests demonstrated good performance of the sealant studied and possibility of its application in SOFCs. [ABSTRACT FROM AUTHOR]

The joining of ceramic and metal (interconnect) parts is one of the main challenges in the development of solid oxide fuel cells (SOFC). A promising approach to solving this problem is the use of glassy sealants. In this work, we investigated the effect of yttria additions on the properties of SiO 2 –Al 2 O 3 –CaO–Na 2 O–ZrO 2 –Y 2 O 3 glass sealants. An increase in the concentration of yttria is shown to reduce the tendency of the glasses under study to crystallisation. A glass containing 4 wt% of Y 2 O 3 is found to be amorphous, even after exposure at 850 °C for 100 h. Moreover, the defectiveness of the glass microstructure, after sealing, is found to decrease along with a growth in the Y 2 O 3 concentration. The developed non-crystallising sealant was successfully applied for joining a YSZ ceramic and an Fe–Ni–Co alloy having the phase transition of around 500 °C. The use of the non-crystallising sealant allows us to join materials with very different thermal expansion coefficients and to avoid cracking under cooling, which might occur due to a large difference in thermal expansion coefficients. [ABSTRACT FROM AUTHOR]

Abstract SiO 2 -Al 2 O 3 -B 2 O 3 -Na 2 O based glass sealant compositions were designed for the development of GMJ using extreme vertices methodology. The effect of the glass sealant individual constituent on wettability, Glass transition temperature (T g), Crystallization temperature (T c), thermal conductivity, and density was analyzed with the help of analysis of variance technique (ANOVA). The increase in SiO 2 constituent in glass sealant decreased the spreading area (mm2) of glass sealant and increased the value of contact angle (θ) formed by glass sealant over the SS304 metal substrate. The T g and T c of glass sealant also increased as SiO 2 content increased. The addition of B 2 O 3 and Na 2 O in glass sealant system reduced the T g and T c of glass sealant. The developed regression model was validated and it was observed that the experimental and predicted results nearly matched with an error less than 5% in most of the cases. [ABSTRACT FROM AUTHOR]

Sealing performance and chemical compatibility of SrO–La 2 O 3 –Al 2 O 3 –SiO 2 glass sealants with bare and Mn–Co spinel coated SUS430 ferritic alloys are investigated. The low–SrO glasses (≤40 mol%) show good wettability and adherence to the bare SUS430 alloy due to their lower viscosity and negligible reactions with the alloy. The high–SrO glass (e.g. 45 mol%) exhibits higher viscosity and more serious reactions with the bare SUS430 alloy. The formation of SrCrO 4 with higher CTE causes obvious delamination and dramatic oxidation of the alloy at the glass/alloy interface. In contrast, Mn–Co spinel coating has good compatibility with both SrO–La 2 O 3 –Al 2 O 3 –SiO 2 glasses and Fe–Cr ferritic alloy. Moreover, the Mn–Co spinel coating on the alloy can effectively restrain the diffusion of Fe and Cr and the reactions between the glasses and the alloy. Due to the ameliorated interfacial microstructure, sealing performance can be improved by applying the Mn–Co spinel coating on SUS430 alloy, especially for the bonded couple with high–SrO glass. [ABSTRACT FROM AUTHOR]