Oxidation protection of C/C–SiC composites by an electrophoretically deposited mullite precursor

Oxidation protection of C/C–SiC composites by an electrophoretically deposited mullite precursor: Cyclic thermogravimetric analysis

“…These measurements showed that the synthesis of a mullite precursor suitable for EPD is possible under the conditions described in our previous paper. 2 In order to prolong the oxidation protection of the mullite layers under cyclic thermal conditions additional suspensions based on the obtained mullite precursor sol were prepared. A nanoscale Al 2 O 3 powder (Degussa GmbH, Germany) with an average particle size of 13 nm was added which should serve as a reservoir for mullite formation from the growing SiO 2 layer during oxidation.…”

“…1,2 The SiC layer was chemically vapour deposited after the C/C substrate had first been capillary infiltrated with liquid silicon. As both processes take place at high temperatures many cracks develop in the SiC layer after cooling down to room temperature.…”

The Electrophoretic Deposition of Inorganic Nanoscaled Materials-A Review-

“…Another application of sol-gel EPD has been presented by Damjanovic et al, 56 who fabricated protective mullite coatings on CC-SiC composites through hydrolysis and condensation of tetraethoxysilane TEOS and aluminium-tri-secbutylate. Sol-gel processing combined with EPD has also been developed for production of SiC whisker reinforced zirconia composites of high microstructural homogeneity.…”

“…56 Titania coatings fabricated by EPD of commercial TiO 2 nanoparticles mentioned above P25, Degussa, Germany on SiC and carbon fibres were shown to provide protection up to 1000c C in oxidising atmosphere. 42,43 In case of carboncarbon composites, silica, alumina and silica-alumina mullite composition suspensions were used and the nanoscaled coatings produced were shown to provide oxidation protection at 600c C. 55 In similar research, hydrothermally derived yttrium disilicate Y 2 Si 2 O 7 nanopowder 12 nm average size was dispersed in water at pH 9.7 and electrophoretically deposited on SiCSiC composite plates at constant voltage of 8 V for 1.5 min.…”

Yttrium silicate coating system for oxidation protection of C/C–Si–SiC composites: Electrophoretic deposition and oxygen self-diffusion measurements

“…In our previous works [12][13][14][15] we used electrophoretic deposition (EPD) to produce mullite layers for extended oxidation protection of C/C-Si-SiC composites 12-14 as well as electrodes and electrolytes for solid oxide fuel cells. 15 The aim of this work was to prepare yttrium silicate powders and to use them for the production of protective coatings by means of electrophoretic deposition.…”