Abstract: Transparent glass-ceramics have found extensive applications in smart terminals and wearable devices due to their exceptional optical and mechanical properties, whose performance characteristics are intrinsically governed by the crystalline phase parameters, including species, concentration, dimensional features, and spatial distribution of nanocrystals within the glass matrix. Transparent Li₂O-ZnO-Al₂O₃-SiO₂ (LZAS) glass-ceramics were fabricated via a melt-heat treatment method, and the effect of B₂O₃ content on their structural evolution, crystallization behavior, and properties was systematically investigated. Results indicate that as the B₂O₃ content in the glass increases from 1% (mole fraction, same below) to 5%, the [BO₄] within the glass gradually transforms into [BO₃]. The proportion of [BO₃] stabilizes at approximately 49% when the B₂O₃ content ranges from 3% to 5%. Glasses containing 1% to 3% B₂O₃ tend to undergo surface crystallization after heat treatment at 760 ℃. In contrast, glasses with B₂O₃ content no less than 4% precipitate uniformly distributed spherical crystals within the bulk glass-ceramic matrix after crystallization at 780 ℃. Increasing the B₂O₃ content lowers the crystallization temperature required for bulk crystallization. The sample prepared from the glass containing 4% B₂O₃ and crystallized at 760 ℃ exhibits a transmittance of 65%, a Vickers hardness of (6.77±0.07) GPa, and a bending strength of (172.7±8.1) MPa.

Key words: B₂O₃, glass-ceramics, Li₂O-ZnO-Al₂O₃-SiO₂, β-quartz solid solution, crystallization kinetics, Vickers hardness