Sr2+/Y3+ co-doped MgO-Al2O3-SiO2-based glasses and transparent glass-ceramics: Crystallization, structure and properties

Abstract Generally, glass-ceramics possess better properties than their parent glasses. Here, we successfully prepared Sr 2+ /Y 3+ co-doped MgO-Al 2 O 3 -SiO 2 -based glasses and transparent glass-ceramics. The results revealed that the glass stability for the parent glasses increased and then decreased as the SrO content increased, showing the opposite trend of crystallinity under the same heating conditions. Structurally, the bonding strength between the structural groups showed the same trend as the glass stability. In addition, the main crystalline phases in the glass-ceramics were cordierite (Mg 2 Al 4 Si 5 O 18 ), magnesium aluminum silicate (Mg 2 Al 4 Si 5 O 18 ) and strontiumosumilite (Sr 0.91 Mg 2 (Al 5.82 Si 9.18 O 30 )). Regarding the microstructures of the glass-ceramics, spherical or near-spherical grains appeared. As for the physical properties of the glass-ceramics, the density initially increased and then decreased, while the molar volume followed the opposite trend with the increasing SrO concentration. Analysis of the mechanical properties showed that the Vickers hardness, bending and compressive strength of the glass-ceramics first decreased and then increased with the variation of the SrO and Y 2 O 3 contents.