Effects of ZnO, FeO and Fe 2 O 3 on the spinel formation, microstructure and physicochemical properties of augite-based glass ceramics

Augite-based glass ceramics were synthesised using ZnO, FeO, and Fe 2 O 3 as additives, and the spinel formation, matrix structure, crystallisation thermodynamics, and physicochemical properties were investigated. The results showed that oxides resulted in numerous preliminary spinels in the glass matrix. FeO, ZnO, and Fe 2 O 3 influenced the formation of spinel, while FeO simplified the glass network. FeO and ZnO promoted bulk crystallisation of the parent glass. After adding oxides, the grains of augite phase were refined, and the relative quantities of augite crystal planes were also influenced. All samples displayed good mechanical properties and chemical stability. The 2wt% ZnO-doping sample displayed the maximum flexural strength (170.3 MPa). Chromium leaching amount values of all the samples were less than the national standard (1.5 mg/L), confirming the safety of the materials. In conclusion, an appropriate amount of zinc-containing raw material is beneficial for the preparation of augite-based glass ceramics.