Evaluation of the Mechanical and Electrical Properties of Spark Plasma Sintered Titanium Carbide Reinforced Alumina Ceramic Composite

Spark Plasma Sintering (SPS) is identified as a suitable technique to prepare the alumina titanium carbide composite to overcome the difficulty in fabricating it through other consolidation method. The present work focuses on the fabrication and characterization of a series of titanium carbide reinforced alumina ceramic composites using a spark plasma sintering process. The titanium carbide reinforcement on the alumina matrix is varied between 20 and 35 wt.%, in order to improve the electrical conductivity and fracture toughness of the composites. The particle size of the starting powders at received and ball milled conditions was analysed through Particle size analyser and Scanning Electron Microscope (SEM). Microstructural analysis revealed that the TiC reinforcement is uniformly dispersed in the sintered composite. XRD report showed that α-alumina and titanium carbide were the two dominant phases without the formation of any reaction phases. Further, the correlation between mechanical and physical properties of the prepared composite was investigated as a function of TiC. Various fracture toughening indicators like crack deflection, bridging and branching were analysed by Vicker’s indentation method. Electrical resistivity of the sintered compact decreases proportionally with the increase in titanium carbide constituents. Maximum density (98.80%) and hardness (20.56 GPa) was obtained for 30 wt. % reinforced composite. Almost 40% improvement in fracture toughness is noted for 25 wt. % reinforced composite. This work demonstrates the synthesis and fabrication of alumina titanium carbide composites at low temperature via SPS resulted in obtaining an intact compact with improved mechanical and electrical properties.