Impact of high-temperature sintering on SiO₂−LiO₂−Al₂O₃−K₂O−P₂O₅ glass ceramics with ZrO₂ and Y₂O₃ additives

The influence of multi-step sintering at high temperatures was used to meticulously characterize the crystallization, mechanical, and optical properties of a (Formula presented.) glass system with the addition of (Formula presented.) and (Formula presented.) (Formula presented.). The research began with a novel base glass composition of 3.8 wt% (Formula presented.) (Formula presented.), 4.2 wt% (Formula presented.) (Formula presented.), 4.5 wt% (Formula presented.) (Formula presented.), 35 wt% (Formula presented.), and 2.5 wt% (Formula presented.) (Formula presented.), to which 47 wt% (Formula presented.) and 3 wt% (Formula presented.) (Formula presented.) added. The initial glass powder was sintered in two steps at low temperatures. Either 500 (Formula presented.) for 10 min or 500 (Formula presented.) for 10 min then a raise to 650 (Formula presented.) for 20 min was used in the first step. Then, the second step of sintering was done at 850 (Formula presented.). Finally, after the pellet preparation, final calcination was conducted at 1450 (Formula presented.). The resulting microstructure was a composite material with various grain components embedded within a glass matrix. The low first sintering temperature triggered the optimum crystal growth, and after the final calcination process, a new glass-ceramic named (Formula presented.) – (Formula presented.) was synthesized. The synthesized ceramics demonstrated strong diametral tensile strength and excellent Vickers micro-hardness values, a remarkable refractive index, and optical band gaps larger than 3.1 eV. Consequently, the process of multi-step sintering at high temperatures clenches the impending manufacture of a novel composite ceramic having remarkable hardness and good optical properties that encourage several biological, technological, and industrial applications.