Dense bulk silicon oxycarbide glasses obtained by spark plasma sintering

作者：Alejandra Mazo M; Palencia Cristina; Nistal Andres; Rubio Fausto; Rubio Juan; Luis Oteo Jose

来源：Journal of the European Ceramic Society, 2012, 32(12): 3369-3378.

DOI：10.1016/j.jeurceramsoc.2012.03.033

• Sintering
• Nanocomposite
• Hardness
• Thermal conductivity
• Spark plasma sintering

Dense silicon oxycarbide glasses (SiOC) have been produced by spark plasma sintering (SPS) of SiOC powders. Raw powders were obtained by pyrolysis under nitrogen at 1100 degrees C of tetraethylorthosilcate/polydimethylsiloxane (TEOS/PDMS) hybrids. SPS experiments were carried out at 1300 and 1500 degrees C at 10 and 80 MPa and then were studied by chemical analysis, Si-29 and C-13 MAS NMR, ATR, Raman, XRD, FE-SEM, density, porosity, microhardness (H-v) and thermal conductivity (K). The SiOC materials are formed by SixOC4-x units within a silica matrix where silicon carbide and graphite nanodomains are also present. After the SPS treatment the silicon carbide crystallite size is close to 2.5 nm. At 1300 degrees C and 1500 degrees C the carbon nanodomain size is close to 3 nm and 2 nm, respectively. H-v values vary from 3.4 to 9.15 GPa, for 30% and 1% of porosity, respectively. Finally, K is always close to 1.38 W m(-1) K-1.

• 出版日期2012-9