Composites Based on MAX-Phase TiSiC Based Composites Obtained by Vacuum and Spark Plasma Sintering

For the synthesis of composites based on the MAX-phase TiSiC, different approaches based on heat treatment and consolidation of powder mixtures 3Ti/1.8SiC/0.8C, 2Ti/1.2SiC/1.8TiC are considered. The first approach consists in powder heat treatment by vacuum sintering at 1400°C for 1 h and spark plasma sintering at 1350°C and a pressure of 50 MPa. The second approach consists in two-stage heat treatment, including additional consolidation by spark plasma sintering of vacuum-sintered composites. For each of the approaches, the influence of temperature and holding time during spark plasma sintering on the phase composition, density and porosity of the obtained composites has been determined. It is found that the consolidation of TiSiC–TiC–TiSi–TiSi and TiSiC–TiC composites obtained by vacuum sintering by spark plasma sintering with the addition of 5 wt. % SiC leads to the formation of high-density Ti3SiC2–TiC–TiSi2 composites with an open porosity index of up to 0.3% and MAX-phase content from 9 to 33 vol. % depending on the sintering temperature (1300–1400°C). It is shown that the microstructure of the composite surfaces synthesized by spark plasma is represented by agglomerates of MAX-phase grains of TiSiC, TiC and inclusions of secondary phases (SiC, TiSi — depending on the sintered composition).