Aluminum titanate (Al2TiO5) was synthesized from Al2O3-TiO2 system by solid-phase reaction with additives of light magnesium carbonate and SiO2, incorporating with silicon carbide (SiC) particle. The influence of additives on the phase composition, microstructure configuration, sintering, and thermomechanical properties of the developed materials was investigated. The experimental results illustrated that the utilization of additives with applicable contents was conducive to the development of complex microstructures. The microstructures characterized by microcracks matrix together with interlocked grains were identified. The samples incorporating SiC and SiO2 simultaneously displayed exceptional densification properties and microstructure as a result of a SiO2 liquid phase accelerating SiC oxidation. Meanwhile, high flexural strength (41.51 MPa) and low thermal expansion coefficient of 0.485 × 10−6 K−1 (RT-1000 °C) were detected, encouraging refractory applications with high thermomechanical solicitations.