Microstructure and Mechanical Properties of Al2O3/Tial In Situ Composites Doped with Cr2O3
Al2O3/TiAl composites were successfully fabricated by hot-press-assisted exothermic dispersion method with elemental powder mixtures of Ti, Al, TiO2 and Cr2O3. The effect of Cr2O3 addition on the microstructures and mechanical properties of Al2O3/TiAl composites has been characterized. The results show that the Rockwell hardness, flexural strength and fracture toughness of the composites increase with increasing Cr2O3 content. When the Cr2O3 content is 3.5 wt %, the flexural strength and the fracture toughness reach the maximum value of 658.7 MPa and 7.2 MPa•m1/2, respectively. The improvement of mechanical properties is firstly associated with a more homogeneous and finer microstructure developed by addition of Cr2O3; secondly, it is related to the increase of the ratio of α2-Ti3Al/γ- TiAl matrix phases.
Jianmin Zeng, Taosen Li, Shaojian Ma, Zhengyi Jiang and Daoguo Yang
F. Wang et al., "Microstructure and Mechanical Properties of Al2O3/Tial In Situ Composites Doped with Cr2O3", Advanced Materials Research, Vols. 194-196, pp. 1736-1739, 2011