Flash spark plasma sintering of Zr<sub>1−</sub><i><sub>x</sub></i>Ti<i><sub>x</sub></i>C solid solution

Zr1−xTixC (x = 0, 0.2, 0.4, 0.6, 0.8, 1) solid solution ceramics were fabricated by flash spark plasma sintering (FSPS). The phase composition, microstructure, and mechanical property of the flash sintered ceramics were investigated. The results showed that the composition of Zr1−xTixC solid solution plays a key role on the densification of the ceramics. A high relative density (98.6 %) and hardness (>20 GPa) was achieved in a solid solution composition of Zr0.4Ti0.6C. The unique in-situ high temperature, fast cooling rate, and mold-free sintering in the FSPS sintering process leads to the formation of gradient microstructure in Zr1−xTixC solid solution, where the corresponding density and hardness show gradient distribution characteristics.