Crystallization behavior of BaO-CaO-SiO2-B2O3 glass sealant and adjusting its thermal properties for oxygen transport membrane joining application

In this work, the thermal stability of a BaO-CaO-SiO2-B2O3 glass sealant, named H, was investigated by differential scanning calorimetry (DSC). The crystallization behavior of glass H as the sealant matrix was investigated by a combination of experimental X-ray diffraction (XRD) analysis and thermodynamic simulation with the FactSage package. A good agreement was found between the Rietveld refinement of XRD experiments and the FactSage simulation. Particular attention was also given to the influence of the Sr2SiO4 filler added to the glass matrix H on the thermal expansion and microstructures of glass-Sr2SiO4 composites by means of dilatometry and scanning electron microscopy (SEM). The reinforced 20 wt% Sr2SiO4 composite (HS2S20) showed excellent properties and, thus, its joining performance was investigated using SrTi0.75Fe0.25O3-delta (STF25) and Aluchrom as promising oxygen transport membrane (OTM) and counterpart, respectively. The joining behaviors were investigated by comparing different joining temperatures. 920 degrees C is the best joining temperature for HS2S20 sealant.

Automated summary

In this study, the thermal stability of a BaO-CaO-SiO2-B2O3 glass sealant (H) was investigated using differential scanning calorimetry (DSC). The crystallization behavior of glass H was examined through experimental X-ray diffraction (XRD) analysis and thermodynamic simulation with FactSage. The influence of Sr2SiO4 filler on the thermal expansion and microstructures of glass-Sr2SiO4 composites was also studied using dilatometry and scanning electron microscopy (SEM). The reinforced 20 wt% Sr2SiO4 composite (HS2S20) showed excellent properties, and its joining performance with SrTi0.75Fe0.25O3-delta (STF25) and Aluchrom as oxygen transport membranes (OTM) was investigated, with the best joining temperature found to be 920 degrees C for HS2S20 sealant.