Microstructure of Ti₃SiC₂ prepared by the in-situ hot pressing/solid-liquid reaction process

The microstructure of Ti₃SiC₂ ceramic prepared by the in-situ hot pressing/solid-liquid reaction process was investigated by transmission electron microscopy. TiC and SiC were identified to be the main impurity phases in this material. The presence of TiC inclusions in Ti₃SiC₂ resulted in high density of dislocations within Ti₃SiC₂ matrix and even interfacial cracking. The SiC impurities were one-dimensional disordered, i.e. with overwhelming of stacking faults and could be distinguished from TiC. Beside the observed impurities imbedded in Ti₃SiC₂, an interesting phenomenon was that needle-shaped Ti₃SiC₂ was also observed within TiC grains. The needle-shape Ti₃SiC₂ grew in TiC following the crystallographic relations of (111) TiC // (0001) Ti₃SiC₂, (002) TiC // (11̄04) Ti₃SiC₂, and [11̄0] TiC // [110] Ti₃SiC₂. Slip trace of basal plane dislocations were observed in Ti₃SiC₂ and the dislocations pile up at grain boundaries suggesting that significant plastic deformation would be expected in single crystal or coarse-grain material.