Structure, physical properties, crystallization and sintering of iron-calcium-aluminosilicate glasses with different amounts of ZnO

Abstract

Iron-calcium-aluminosilicate glasses with additions of different amounts of ZnO were prepared. The influence of ZnO on the structure, physical properties, crystallization and sintering of the glasses has been investigated. The FTIR spectroscopy reveals that the addition of ZnO leads to the increase of non-bridging oxygen. ZnO acts as a glass modifier, residing in the voids of the glass network, resulting in a linearly increase of the glass density with ZnO. Due to the increasing discontinuity of the glass network, the glass transition point decreases with ZnO, indicating the reduction of the glass viscosity, which facilitates the sintering of the glass with a high amount of ZnO. However, Zn2+ also has aggregation effect on the glass network, leading to the decrease of the thermal expansion coefficient. All glasses show surface crystallization, however, the crystallization tendency decreases with ZnO. Ferroan wollastonite (Ca2.87Fe0.13(SiO3)3 and silicon oxide are mainly identified in the thermally treated samples.