Owing to the high expenses and numerous potential avenues for formula research in ceramic production, obtaining cost-effective and high-quality ceramic formulas for high-performance ceramics poses significant challenges. To address this issue, a flux formula optimization procedure is proposed to develop the predictive ceramic formula P18, which allows precise control of the Al/Si ratio and is compatible with standard manufacturing processes. This cost-effective method enables the visual examination of ceramics’ physical, mechanical and thermodynamic properties. It is found that sintering temperature plays a crucial role in phase and microstructure evolution by classical phenomenological kinetic theory. Moreover, the sintered sample P18 exhibits remarkable mechanical performance, with a strength of 96.82 ± 2.0 MPa and fracture toughness of 1.89 ± 0.02 MPa·m1/2. These outstanding properties can be attributed to the reinforcing effects of multiple phases, such as high-strength corundum and in situ mullite whiskers. The mechanical mechanisms of the resulting ceramic tiles include particle reinforcement, microcrack deflection, intergranular and transgranular fracture, and in situ mullite whisker bridge pull-out, which collectively contribute to increase energy consumption per unit length, thus reducing the risk of brittle fractures.