Crystallization Behavior of SiO₂–Al₂O₃–ZnO–CaO Glass System at 1123–1273 K

Abstract

The crystallization characteristics of a glass, used as the matrix of high‐temperature protective coatings, based on SiO2–Al2O3–ZnO–CaO with the addition of TiO2 and ZrO2 at a temperature range of 1123–1273 K have been investigated. At 1273 and 1173 K, tetragonal zirconia doped with Ti and Ca, initially precipitated from the melt. At 1123 K, however, zirconolite instead of zirconia precipitated as the primary phase. The secondary precipitates were zircon and titanite in the glass fired at 1273 K, titanite and willemite at 1173 K, and zirconolite, titanite, and willemite at 1123 K, respectively. It is proposed that the temperature‐dependent solubility of Ca and Ti in ZrO2 significantly affects the type and volume fraction of crystals precipitated from the glass.

Microstructure stabilization of a novel glass/YSZ composite coating material by adding alumina particles

“…Additionally, diffraction peaks of tetragonal and monoclinic zirconia are found in the XRD patterns after sintering at 1000 1C for 1 h. However, they disappeared after sintering for 20 h. Instead, peaks of zircon appeared. This confirmed that the formation of zircon was due to the reaction between the base glass and the zirconia precipitates, which was consistent with our previous studies [33,41]. Diffraction peaks of zirconolite and albite were not found in the XRD patterns after sintering at 1000 1C for either 1 h or 20 h. Phase evolution of E30A specimens at 900 1C and 1000 1C is shown in Fig.…”

“…At temperatures of 900-1000 1C, elements of Ca and Ti were likely to segregate together and form titanite (nominally CaTiSiO 5 ) in the base glass [33,41]. However, CaZrTi 2 O 7 instead of CaTiSiO 5 was detected for E10A and E30A specimens sintered at 900 1C.…”

“…From our previous papers [33,41], it can be seen that CaZrTi 2 O 7 and t-ZrO 2 was the primary crystalline phase during the crystallization process of the base glass at 850 1C and 900 1C-1100 1C, respectively. Their precipitation is dependent on the sintering temperature.…”

“…Crystallization behavior of the base glass and phase evolution of the YSZ/glass composites at temperatures of 900 1C, 1000 1C and 1100 1C can be found in detail in our previous papers [33,41]. Fig.…”

Formation kinetics of multi-layered interfacial zone between γ-TiAl and glass–ceramic coatings via interfacial reactions at 1000°C

“…This phenomenon implies an interdependent relationship between a-quartz and b-cristobalite, which provides a further evidence to indicate the transformation of a-quartz particles to b-cristobalite phase in the coating. Besides, the detected low intensity zircon was the precipitates of the glass matrix [29,40].…”