Glass forming, crystallization, and physical properties of MgO-Al2O3-SiO2-B2O3 glass-ceramics modified by ZnO replacing MgO

Abstract This study focused on the glass forming, crystallization, and physical properties of ZnO doped MgO-Al 2 O 3 -SiO 2 -B 2 O 3 glass-ceramics. The results show that the glass forming ability enhances first with ZnO increasing from 0 to 0.5 mol%, and then weakens with further addition of ZnO which acted as network modifier. No nucleating agent was used and the crystallization of studied glasses is controlled by a surface crystallization mechanism. The predominant phase in glass-ceramics changed from α-cordierite to spinel/gahnite as ZnO gradually replaced MgO. The phase type did not change; however, the crystallinity and grain size in glass-ceramics increased when the glasses were treated from 1030 °C to 1100 °C. The introduction of ZnO can improve the thermal, mechanical, and dielectric properties of the glass-ceramics. The results reveal a rational mechanism of glass formation, crystal precipitation, and evolution between structure and performance in the x ZnO-(20- x )MgO-20Al 2 O 3 -57SiO 2 -3B 2 O 3 (0 ≤ x ≤ 20 mol%) system.