(Ti,Cr)C Synthesized In Situ by Spark Plasma Sintering of TiC/Cr₃C₂ Powder Mixtures

抄録

(Ti,Cr)C was synthesized and consolidated in situ by spark plasma sintering (SPS) of two TiC/Cr₃C₂ powder mixtures of distinctly different particle sizes. SPS of both mixtures successfully produced single-phase (Ti,Cr)C in two minutes at 1800°C. It was found that the nano-scale mixture consists of fine and uniformly dispersed TiC/Cr₃C₂ particles while the micron-scale mixture consists of particles aggregated and unevenly distributed. The (Ti,Cr)C consolidated using nano-scale mixture retained an equilibrium grain structure linear grain boundaries thanks to the fine and uniform elemental distribution. On the contrary, the grain boundaries of (Ti,Cr)C consolidated using micron-scale mixture were heavily serrated with Cr-richer composition. It is believed that Cr₃C₂ melts and forms networks where it starts to react with TiC to form solid solution leaving serrations along the grain boundaries because of its non-uniform distribution. The higher fracture toughness of (Ti,Cr)C consolidated from nano-scale mixture may be attributed to its uniform microstructure.