Formation of a Metastable Celsian‐Cordierite Eutectic Structure During the Crystallization of a Ba‐Osumilite Glass–Ceramic

Abstract

This work addresses the formation conditions and stability of a celsian‐cordierite eutectic structure produced during the crystallization of a barium magnesium aluminosilicate (BMAS) glass–ceramic with the Ba‐osumilite stoichiometry. The melt‐derived BMAS glass–ceramic was pulverized and subsequently hot pressed to produce sintered powder compacts, some of which were subjected to post‐sintering heat treatments in air. The study of the devitrified BMAS glass revealed that a metastable celsian‐cordierite eutectic structure resulted from the prolonged annealing of the BMAS glass–ceramic between 860° and 1000°C. The celsian‐cordierite eutectic structure transformed to the thermodynamically stable Ba‐osumilite phase when annealed at temperatures >1000°C.