Fabrication and microstructure characterization of Ti3SiC2 synthesized from Ti/Si/2TiC powders using the pulse discharge sintering (PDS) technique

Ti/Si/2TiC powders were prepared using a mixture method (M) and a mechanical alloying (MA) method to fabricate Ti3SiC2 at 1200degrees-1400degreesC using a pulse discharge sintering (PDS) technique. The results showed that the Ti3SiC2 samples with <5 wt% TiC could be rapidly synthesized from the M powders; however, the TiC content was always >18 wt% in the MA samples. Further sintering of the M powder showed that the purity of Ti3SiC2 could be improved to >97 wt% at 1250degrees-1300degreesC, which is similar to200degrees-300degreesC lower than that of sintered Ti/Si/C and Ti/SiC/C powders using the hot isostatic pressing (HIPing) technique. The microstructure of Ti3SiC2 also could be controlled using three types of powders, i.e., fine, coarse, or duplex-grained, within the sintering temperature range. In comparison with Ti/Si/C and Ti/SiC/C mixture powders, it has been suggested that high-purity Ti3SiC2 could be rapidly synthesized by sintering the Ti/Si/TiC powder mixture at relatively lower temperature using the PDS technique.