Ti2AlC bulk material was synthesized by hot pressing of mixture powders of TiC, Ti, Al and active carbon. The phase compositions of resultant product at different temperature were detected by X-ray diffractometer. The microstructures of the samples were observed by SEM. Finally, the mechanical properties and thermal properties of the sample at 1400 ℃ were measured. The results show that high purity Ti2AlC material with little Ti3AlC2 can be synthesized by hot pressing 0.5TiC/1.5Ti/1.0Al/0.5C at 1 400 ℃. Ti2AlC exhibits high mechanical properties and metallic electrical properties. Its fracture toughness is 7.0 MPa·m1/2, its flexural strength is 384 MPa at room temperature, and its electrical conductivity is 2.56×106 Ω1·m-1 at room temperature.
High-purity Ti2AlN ceramic was prepared at 1300 ℃ by hot pressing(HP)of Ti/Al/TiN powders in stoichiometric proportion.The sintered product was characterized using X-ray diffraction(XRD)and MDI Jade 5.0 software(Materials Data Inc,Liverpool,CA).Scanning electron microscopy(SEM)and electron probe micro-analysis(EPMA)coupled with energy-dispersive spectroscopy(EDS)were utilized to investigate the morphology characteristics.The results show that Ti2AlN phase is well-developed with a close and lamellar structure.The grains are plate-like with the size of 3-5 μm,thickness of 8-10 μm and elongated dimension.The density of Ti2AlN is measured to be 4.22 g/cm3,which reaches 97.9% of its theory value.The distribution of Ti2AlN grains is homogeneous.
A ternary-layered carbide Ti2AlC material could be synthesized by spark plasma sintering（SPS） technology using elemental powder mixture of Ti, Al and active carbon. By means of XRD and SEM, phases were identified and microscopically evaluated. The experimental results show that the main phase in the product was fully crystallized Ti2AlC with small particle size when sintered at 1200℃. The synthesis temperature of SPS was 200-400℃ lower than that of hot pressing （HP） or hot isostatic pressing （HIP）. Through thermodynamics calculations, the mechanism of Ti2AlC was studied by calculating changes of Gibbs free energy of reactions.
