Spark plasma sintering influence on microstructure and mechanical properties of Ti:Ta/carbonitride ceramic matrix composites

A mechanically induced self-sustaining reaction was carried out to synthesize a Ti 0.9 Ta 0.1 C 0.5 N 0.5 /Co powdered cermets, and then they were sintered by spark plasma sintering. Microstructural parameters effects studied by image analysis, and chemical composition (studied by Rietveld analysis) on the microhardness, hardening rate, fracture toughness, transverse rupture strength, and Young's modulus were related to the sintering conditions. The optimization of the sintering conditions (1150 °C, 30 MPa, and 8 min' dwell time) drove to a homogeneous microstructure and outstanding mechanical properties. Also, the tantalum was suggested to influence the interfacial energies of the system, yielding a stronger hard phase skeleton. • Highly densified products by SPS were obtained. • Hardening rate was quantified as a function of the microhardness vs. run time. • Ta presence is believed to be found at the grain and phase boundaries. • Tantalum is suggested to influence the interfacial energies of the system. • A stronger hard phase skeleton was observed by the formation of a Ta intermetallic binder.