Microstructure and thermomechanical characteristics of spark plasma sintered TiC ceramics doped with nano-sized WC

• Published in: Ceramics international 2019-02, Vol.45 (2), p.2153-2160
• Main Authors: Sabahi Namini, Abbas, Ahmadi, Zohre, Babapoor, Aziz, Shokouhimehr, Mohammadreza, Shahedi Asl, Mehdi
• Format: Article
• Language: English
• Subjects: Microstructure; Spark plasma sintering; Thermomechanical characteristics; Titanium carbide; Tungsten carbide
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2018.10.125

In this study, we studied the effects of nano-sized WC addition (0, 1.5 and 3 wt%) on microstructure and thermomechanical properties of TiC-based ceramics. WC-doped TiC matrix composites were sintered by spark plasma at 1900 °C under 40 MPa for 7 min. The densification behavior of WC-doped TiC ceramics was characterized and compared with the monolithic TiC. Microstructural investigation of the sintered specimens was achieved by scanning electron microscopy. X-ray diffraction analysis was carried out to determine the phase evolution of the prepared ceramics. In addition, the thermal and mechanical characteristics including thermal conductivity, Vickers hardness and flexural strength were evaluated and their relationship with the microstructural features was discussed. Thermal conductivity increment and the relevant pronounced effects on grain growth inhibition were observed for TiC-3 wt% WC. The obtained results demonstrated that the addition of 3 wt% WC plays a vital role in sinterability enhancement of TiC by accelerating the densification. The highest relative density (99.9%), Vickers hardness (28.6 GPa) and flexural strength (620 MPa) were obtained for the TiC ceramic doped with 3 wt% nano-sized WC.