Preparation of TiC/Ni3Al composites by upward melt infiltration

TiC/Ni3Al composites have been prepared using upward infiltration method. The densification was performed by both Ni3Al melt filling and TiC sintering during the infiltration. The dissolution of TiC in liquid Ni3Al has been evidenced by finding Ni-3(Al,Ti)C after fast cooling in the TiC/Ni3Al composites. The dissolution may be responsible for the infiltration and sintering. Compared with downward infiltration, the upward infiltration brought about higher strength and fracture toughness and shorter infiltration time. TiC/20 vol. pct Ni3Al composite processed by upward infiltration had a flexural strength of 1476 MPa with a statistic Weibull modulus of 20.2 and a fracture toughness of 20.4 MPa root m. Better mechanical properties may be attributed to melt unidirectional movement in upward infiltration.