Reinforcing and toughening of TiAl composites by doping Sm2O3
(Key Laboratory of Auxiliary Chemistry and Technology for Chemical Industry of Ministry of Education,
School of Materials Science and Engineering, Shaanxi University of Science and Technology, Xi’an 710021, China)
School of Materials Science and Engineering, Shaanxi University of Science and Technology, Xi’an 710021, China)
Abstract: Al2O3/TiAl composites were fabricated by in-situ reaction synthesis using Ti, Al, TiO2 and Sm2O3 as starting materials. Effect of the doping Sm2O3 on the microstructures and properties of the Al2O3/TiAl composites was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and universal properties tests. The results show that the phases of the Sm2O3-doped composites are mainly composed of γ-TiAl/α2-Ti3Al matrix and reinforcing phases of Al2O3 and SmAl. The microstructures of Al2O3/TiAl composites are significantly refined with doping Sm2O3. Doping Sm2O3 has a positive effect on improving the mechanical properties of Al2O3/TiAl composites. When the Sm content is 5% (mass fraction), the flexural strength and fracture toughness reach the maximum values of 658.9 MPa and 10.13 MPa·m1/2, respectively.
Key words: TiAl; Sm2O3; grain size; mechanical properties