Effects of Cr2O3 and CaF2 on the structure, crystal growth behavior, and properties of augite-based glass ceramics.

Glass ceramics were synthetized using Cr 2 O 3 and CaF 2 as additives, and their structure, crystal growth behavior, and physicochemical properties were investigated. The results showed that an excessive amount of Cr 2 O 3 leads to the formation of a spinel structure in the glass matrix and an increase in the number of Q3Si units. The addition of CaF 2 promoted the decomposition of Q2Si into Q1Si and Q3Si. Compared with the sample with Cr 2 O 3 alone, the addition of CaF 2 helped reduce the glass transition and crystallization temperatures, forming sharper crystallization peaks. Although CaF 2 increased the activation energy of crystallization, it increased the degree of crystallinity and Avrami parameter (2.019). In terms of the microstructure, the sample added with CaF 2 formed a snowflake-like structure with a spinel core. An excessive amount of spinel reduced the strength of the samples. The samples (1.5Cr 2 O 3 -3.5CaF 2) exhibited a maximum flexural strength of 149.85 MPa and a good chemical resistance. [ABSTRACT FROM AUTHOR]