The effect of aluminum oxide on the mechanical properties of hot-pressing black titanium dioxide ceramics

Titanium dioxide (TiO2) ceramics, known for their excellent functionality, have been limited in applications due to their relatively weak mechanical properties. In this work, black TiO2 ceramics with superior mechanical properties are achieved through the incorporation of aluminum oxide (Al2O3) additives and hot-pressing method. The black TiO2 ceramic exhibited a remarkable flexural strength of near 400 MPa, which is the highest value known to us to date for similar materials. The influence of Al2O3 on the mechanical properties of black TiO2 ceramics was discussed from the perspective of material microstructures. The Al-Ti-O nanolayer was observed at the grain boundaries, contributing to both the reinforcement of grain boundaries and the refinement of grains along with Al2O3 particles. This study not only developed black TiO2 ceramics with great mechanical properties but also expanded our understanding of the TiO2-Al2O3 material system.