Crystallization of 60SiO₂–20MgO–10Al₂O₃–10BaO Glass Ceramics

Abstract

Three distinctly different microstructures of silica (as quartz and crystobalite), alumina, enstatite, and celsian, were found to develop in a 60SiO2–20MgO–10Al2O3–10BaO glass ceramic. At 1010°C, growth of wormy fibrillar crystals was observed, indicating that crystal growth was diffusion controlled. At the intermediate temperature of 1080°C, a coarse cellular microstructure developed with multiple spherical particles nucleated on their surfaces and in the surrounding glass. At 1200°C, the glass crystallizes in a denderitic morphology but the dendrites were actually fragmented into multiple cube‐shaped enstatite crystals, indicating a transition to interface‐controlled growth. The crystals coarsen with time but maintain their order along the dendrite skeletons.

Cellular growth of 2M-wollastonite in flux growth process relevant to preparation of high aspect ratio particles

“…14,15,17 Cellular and dendritic growths have also been observed in ceramic alloys. [27][28][29] However, in most of those studies, a high aspect ratio was not of the main interest, the cellular and dendritic patterns did not show strong orientation dependence, they often formed locally, or the same phase is not continuous in extended scale, which is critical in 2M-wollastonite preparation. One of the main reasons causing the structural difference is the heat transfer mechanism.…”

“…The second system includes organic alloys such as succinonitrile–acetone, 15 succinonitrile–salol 26 and pivalic acid–ethanol. 27 A more detailed list of such organic compounds or their combinations is available in the literature. 14 Compared with metal alloys, those organic alloys have low melting points, making it easier to handle.…”