Evolution of binary phase TiC/Ti3SiC2 composites from TiC/Ti/Si by hot-pressed reactive sintering

Binary phase TiC/Ti3SiC2 composites have been synthesized by reactive hot-pressed sintering (HPS) with the aim of developing a new hard product. Raw powders of TiC, Ti and Si with compositions 2TiC/1Ti/1Si (2:1:1) and 2TiC/1Ti/1.1Si (2:1:1.1) have been used as the starting materials for the synthesis. The phase content and microstructure of synthesized composites have been analyzed using X-ray diffractometer (XRD) and scanning electron microscope (SEM). The mechanical properties such as four-point flexural strength and fracture toughness have been investigated for different processing parameters. The phase content (Ti3SiC2:TiC) of the composite synthesized from (2:1:1) powder vary from (81:19) to (71:29) with the hot pressing temperature increased from 1500 to 1700 °C. This sample exhibits maximum flexural strength of 627 MPa and fracture toughness of 6.84 MPa m1/2. The maximum apparent density is found to be 4.65 g/cm3 for this sample at optimum hot pressing temperature of 1500 °C. The composite synthesized from (2:1:1.1) composition shows improvement in the mechanical properties compared to 2:1:1 composition. The relationship between the phase content and mechanical properties has been investigated.