Dense bulk silicon oxycarbide glasses obtained by spark plasma sintering

Processing and characterization of polymer precursor derived silicon oxycarbide ceramic foams and compacts

“…The density of pyrolyzed samples is 1.4-1.5 g/cm 3 and geometric density is close to 1.5-1.6 g/cm 3 . Compared to the density values reported in the existing literatures for SiOC [29][30][31], the observed density is lower for the cold pressed and pyrolysed SiOC. This could be attributed to the presence of residual porosity due to the escapement of volatile matter during the thermolysis.…”

Structure properties relationship in silicon oxycarbide glasses obtained by spark plasma sintering

“…Moreover, Mazo et al indicated that there are a maximum SiC crystallite size of around 2 nm in the SPS sintered SiOC coming from the carbothermal reduction of SiO 2 and C [31]. Here, we have shown that in the samples reinforced with SiO 2 , the excess of SiO 2 limits the extent of the formation of SiC bonds.…”

“…The above encountered correspondence of the mechanical properties with the chemical composition is not found when measuring the microhardness of the SPS sintered materials. As observed in Table 3, there is almost no difference in the Vickers microhardness values in all the unreinforced samples but an increase with the addition either of SiC and SiO 2 being the measured values in the range of silicon oxycarbides obtained by the same procedure [31]. As published by other authors [32] an increase of the microhardness values in SiOC nanocoposites is expected, although in the present work, it has been found that the incorporation of Al 2 O 3 nanoparticles acts in detrimental of the mechanical properties of the sintered nanocomposites.…”

“…One of the main advantages of this technique is that there is no necessity to melt the whole sample to obtain fully dense ceramics but only the particle boundary is involved in the sintering process. Therefore, in spite of the fact that the main structure of the SiOC phase is conserved after sintering [31], both the different carbon distribution and the addition of inert fillers provides dense bulk materials with different nanodomain distribution and hence, different mechanical and electrical properties. The short dwelling time necessary to achieve the complete densification indicates that the surface properties will direct the processes occurring during sintering.…”

Small‐Scale Deformation of Pulsed Electric Current Sintered Silicon Oxycarbide Polymer Derived Ceramics

“…wherein dense pellets of SiC–Si 3 N 4 nanocomposites were produced with yttria as an additive. However, there is rather limited literature available on the PECS of SiOC PDCs . For instance, the microstructural evolution of dense SiOC ceramics sintered up to 1600 °C with a hardness of ≈7 GPa and flexural strength of ≈220 MPa was reported by Esfehanian et al .…”