In situ fabrication of TiC/Ti3Al/Ti2AlC composite by spark plasma sintering technology

摘要

A powder mixture of Ti, Al₄C₃ and graphite was adopted to synthesize a new TiC/Ti₃Al/Ti₂AlC composite by spark plasma sintering. The reaction route was proposed from XRD analysis. TiC, Ti₃Al and Ti₂AlC formed from 800°C with TiC _x and Ti₃Al _y acting as the intermediate phases until the reaction process completed at 1200°C. It was found from TEM observation that Ti₃Al underwent an intergrowth relationship with TiC grains inside the Ti₂AlC matrix due to the in situ reaction sintering. The average hardness, fracture toughness, Young’s modulus and bending strength of the composite were 10.2 ± 0.6 GPa, 6.5 ± 0.2 MPa·m1/2, 436 ± 11 MPa and 227 ± 13 GPa, respectively.