Synthesis of a metallic ceramic -Ti3SiC2 by PDS process and its properties

Powder mixtures of Ti/Si/C, Ti/SiC/C, Ti/Si/TiC, Ti/SiC/TiC and Ti/TiSi2/TiC were used for the synthesis of Ti3SiC2 by using a pulse discharge sintering (PDS) process. The Ti/Si/TiC powder was found to be the best among the five powder mixtures for the Ti3SiC2 synthesis. The highest content of Ti3SiC2 can be improved to about 99wt% at the sintering temperature of 1300degreesC for 15 minutes. The relative density of all the synthesized samples is higher than 98-99% at the sintering temperature above 1275degreesC. The nearly single phase Ti3SiC2 was found to show plastic deformation at room temperature and a good machinability. Both electrical and thermal conductivity were found to be more than two times of the value of a control pure Ti sample. The high-temperature mechanical tests confirmed that the Ti3SiC2 samples synthesized by the PDS process displayed a comparable performance with those fabricated by the other techniques.