Impact of high‐temperature sintering on SiO2−LiO2−Al2O3−K2O−P2O5${\rm SiO}_2{-}{\rm LiO}_2{-}{\rm Al}_2{\rm O}_3{-}{\rm K}_2{\rm O}{-}{\rm P}_2{\rm O}_5$ glass ceramics with ZrO2${\rm ZrO}_2$ and Y2O3${\rm Y}_2{\rm O}_3$ additives

Abstract The influence of multi‐step sintering at high temperatures was used to meticulously characterize the crystallization, mechanical, and optical properties of a glass system with the addition of and . The research began with a novel base glass composition of 3.8 wt% , 4.2 wt% , 4.5 wt% , 35 wt% , and 2.5 wt% , to which 47 wt% and 3 wt% added. The initial glass powder was sintered in two steps at low temperatures. Either 500 for 10 min or 500 for 10 min then a raise to 650 for 20 min was used in the first step. Then, the second step of sintering was done at 850. Finally, after the pellet preparation, final calcination was conducted at 1450. 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 – 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.