Synthesis, Structure and Properties of MgO-Al2O3-SiO2-B2O3 Transparent Glass-Ceramics

Abstract

MgO-Al2O3-SiO2-B2O3 system transparent glass-ceramics have been prepared by conventional melt-quenching method followed by controlled crystallization, and their properties were also studied. The crystalline phases, crystal morphology, physical and light transmittance properties of glass-ceramics were characterized by DSC, XRD, FTIR, FE-SEM, thermo-mechanical analyzer and UV spectrophotometer. The results indicated that the crystal phase μ-cordierite turned to α-cordierite with increase in heat treatment temperature, and cordierite nanocrystals with size less than 50 nm were precipitated from the matrix glass, which was confirmed by the X-ray and SEM results. It is observed that the main elements in the glass-ceramics are uniformly distributed from EDS element distribution maps. The light transmittance of glass-ceramics obviously decreases with rising of crystallization time. All things considered, when the parent glass was crystallized at 1045 °C for 1 h, the prepared glass-ceramics possesses good light transmittance (76 %), lower density (2.498 g/cm3), lower thermal expansion coefficient (2.469 × 10− 6/°C), higher bending strength (167 MPa), compressive strength (376 MPa) and higher Vickers hardness (7.8 GPa). The combination of excellent mechanical, thermal and optical properties makes this family of transparent glass-ceramics showing potential applications.