Crystallization of osumilite from modified basaltic glasses

Abstract

Osumilite-type phases, which have high temperature stability and low linear thermal expansion coefficients, were crystallized from modified basalt glass composition. To satisfy the compositional requirements of osumilite molecules, a deliberate amount of kaolin, sand, magnesite and TiO2 should be added to the basalt. The crystallization process was investigated by DTA, X-ray diffractometry and SEM. The effect of compositional changes on bulk crystallization and growth morphology was also studied. The linear thermal expansion coefficient was measured to characterize the produced glass-ceramics.