Influence of SrO content on microstructure and crystallization of glazes in the SiO2–Al2O3–CaO–MgO–K2O system

Abstract

The effect of the SrO addition on the microstructure and structure of the glazes from the SiO 2-Al 2 O 3-CaO-MgO-K 2 O system was investigated in this study. The results were obtained by testing the ability of the frits crystallization, the stability of the crystallizing phases during the single-step fast-firing cycle depending on their chemical composition and the effect of addition of strontium oxide. Differential scanning calorimetry (DSC) curves showed that all glazes crystallized, and diopside and anorthite were mainly identified as dominant phases in the obtained glazes, while the size and amount of each depended on the amount of SrO introduced. The thermal characteristic of the frits was carried out using DSC, and crystalline phases were determined by X-ray diffractometry. The glaze microstructure was investigated by scanning electron microscopy and transmission electron microscopy. Additional information on the microstructure of frits was derived from spectroscopic studies in the mid-infrared range.

Review on silicate and borosilicate‐based glass sealants and their interaction with components of solid oxide fuel cell

“…In a glass system, the role of SrO depends on initial composition; mostly, it acts as a modifier in the glass. Moreover, it is used as a flux with a stronger effect than CaO 193 . SrO generally leads to stable and transparent glasses in the system having a high content of ZrO 2.…”

“…SrO generally leads to stable and transparent glasses in the system having a high content of ZrO 2. 194 When SrO is substituted in a glass system instead of CaO, it promotes higher content of crystallization phases 193,195 . In glasses, up to 25 mol% SrO content and with up to 4 mol% TiO 2 content, CTE is observed in the range of (10.8‐13.6 × 10 −6 °C −1 ).…”

“…199 However, the coating of Mn-Co on Fe-Cr ferritic alloy effectively restrains the diffusion of Fe and Cr into the glass sealant. Grajik et al 193 reported that the increase in the SrO content does not show any significant effect on the value of T g in SiO 2 -Al 2 O 3 -CaO-MgO-K 2 O. However, in these glasses, two crystallization temperatures were present, that is, 975 C to 985 C and 1203 C to 1211 C. The maximum crystallization peaks were shifted to higher temperatures with an increase in the SrO content.…”

“…Moreover, it is used as a flux with a stronger effect than CaO. 193 SrO generally leads to stable and transparent glasses in the system having a high content of ZrO 2.…”

“…When SrO is substituted in a glass system instead of CaO, it promotes higher content of crystallization phases. 193,195 In glasses, up to 25 mol% SrO content and with up to 4 mol% TiO 2 content, CTE is observed in the range of (10.8-13.6 Â 10 À6 C À1 ). There is the presence of different crystalline phases such as Sr 2 SiO 4 , SrTiO 3 , Cr 2 SiO 4 , and CaSiO 3.…”