In-situ synthesized Ti5Si3/TiC composites by spark plasma sintering technology

Sub-microstructured Ti5Si3/TiC composites were in-situ fabricated by through spark plasma sintering (SPS) technique using Ti and nanosized SiC powders without any additive. It was found that the composite could be sintered in a relatively short time (8 min at 1260 degrees C) to 98.8% of theoretical density. After sintering, the phase constituents and microstructures of the samples were analyzed by X-ray diffraction (XRD) techniques and observed by scanning electron microscopy (SEM) and TEM. Fracture toughness at room temperature was also measured by indentation tests. The results showed that fracture toughness of Ti5Si3/TiC composite reached 4.2 +/- 0.4 MPa.m(1/2), which is higher than that of monolith Ti5Si3 (2.5 MPa.m(1/2)).