Ceramic matrix composites (CMCs) based on silicon carbide (SiC) are promising materials for applications as structural components used under high irradiation flux and high temperature conditions. The addition of SiC fibers (SiC_f) may improve both the physical and mechanical properties of CMCs and lead to an increase in their tolerance to failure. This work describes the fabrication and characterization of novel preceramic paper-derived SiC_f/SiC_p composites fabricated by spark plasma sintering (SPS). The sintering temperature and pressure were 2100 °C and 20–60 MPa, respectively. The content of fibers in the composites was approx. 10 wt.%. The matrix densification and fiber distribution were examined by X-ray computed tomography and scanning electron microscopy. Short processing time avoided the destruction of SiC fibers during SPS. The flexural strength of the fabricated SiC_f/SiC_p composites at room temperature varies between 300 and 430 MPa depending on the processing parameters and microstructure of the fabricated composites. A quasi-ductile fracture behavior of the fabricated composites was observed.

The study describes an original approach to the synthesis of composites based on the MAX-phase Ti₃SiC₂ by a combined powder metallurgy technique. The described approach includes a two-stage heat treatment and consolidation of powders by solid-phase vacuum sintering and spark plasma sintering technologies. Powder mixtures 3Ti/1.2Si/2C and Ti/1.2Si/2TiC were considered as feedstocks for the synthesis. The selected mixtures were presintered in a vacuum furnace at a temperature of 1400°C for 1 h. The obtained compacts were milled with the addition of pure silicon powder and spark plasma sintered at a temperature of 1300°C and a pressure of 50 MPa. The silicon overage in each of the sintering steps promoted the phase formation of Ti₃SiC₂. The influence of isothermal holding time at the additional synthesis stage in the range of 5–10 min on phase composition and surface microstructure of the obtained materials was studied. The maximum content of the Ti₃SiC₂ phase, 77.8 vol %, was reached for composites synthesized by the combined sintering of Ti/Si/C and Ti/Si/TiC mixtures at an additional sintering time of 10 and 5 min, respectively. It has been shown that the microstructure of the surfaces of the synthesized composites is represented by elongated grains of the MAX-phase Ti₃SiC₂ with length from 4 to 12 µm, agglomerates of titanium carbide, and precipitations of titanium disilicide.

This paper is devoted to the fabrication of laminated Ti₃SiC₂/Zr based composites from Ti₃SiC₂ filled preceramic paper and Zr powder. The composites represented a “layers-by-layer” structure and were sintered by spark plasma at 1400 °C and 50 MPa for 10-30 min. The densification behavior during the sintering, microstructure of obtained composites and influence of the holding time on the phase composition were studied.

This paper is devoted to proposing a new approach to the synthesis of SiC- and Ti₃SiC₂-based ceramics by using of preceramic paper as a feedstock. A preceramic paper with SiC and Ti₃SiC₂ powder fillers were sintered by spark plasma sintering (SPS) method for holding time 10 minutes under pressure 20-100 MPa. The temperature for the sintering of SiC- and Ti₃SiC₂-filled paper was 2073-2373 K and 1373-1473 K respectively. The influence of sintering parameters on the materials microstructure was analyzed by scanning electron microscopy. It was revealed that with an increase in pressure from 20 to 100 MPa, the microstructure of the materials becomes denser. It agrees with the results of measuring the density of the sintering materials by the hydrostatic weighting. The determination of Young`s modulus by the acoustic method demonstrates that with the increase of the applied pressure during SPS, Young’s modulus of the synthesized SiC- and Ti₃SiC₂-ceramics increase.

For the synthesis of composites based on the MAX-phase Ti₃SiC₂, various approaches based on heat treatment and consolidation of powder mixtures 3Ti/1.8SiC/0.8C and 2Ti/1.2SiC/1.8TiC have been 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 effect of temperature and holding time during spark plasma sintering on the phase composition, density, and porosity of the obtained composites has been determined. It has been found that the consolidation of Ti₃SiC₂–TiC–Ti₅Si₃–TiSi₂ and Ti₃SiC₂–TiC composites obtained by vacuum sintering and spark plasma sintering with the addition of 5 wt % of 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 has been shown that the microstructure of the composite surfaces synthesized by spark plasma is represented by agglomerates of MAX-phase grains of Ti₃SiC₂, TiC, and inclusions of secondary phases (SiC and Ti₅Si₃ depending on the sintered composition).

This paper is devoted to study a structure of SiC-based materials using ultrasonic tomography method. The SiC-based materials were fabricated from preceramic paper using spark plasma sintering (SPS) method. Also as part of the study the Young`s modulus and density of sintered materials were determined and the effect of sintering pressure changing to this parameters value was investigated. The preceramic paper is a composite material including a matrix of organic cellulose fibers and inorganic powder filler (SiC). The sintering temperature and pressure were 2373 K and 20-40 MPa, respectively. The holding time for the sintering process was 10 min. The density of sintered materials was investigated by the hydrostatic weighing method. Ultrasonic tomography was implemented using of single-channel sensor at 10 MHz frequency.