Polymer impregnation and pyrolysis process development for improving thermal conductivity of SiCp/SiC–PIP matrix fabrication

Densification of a SiC-matrix by electrophoretic deposition and polymer infiltration and pyrolysis process

“…It is also obvious that the density of the samples formed by EPD and subsequently infiltrated with the pre-ceramic polymer, pyrolysed and crystallized (PIP) increases progressively with the number of PIP cycles, achieving 86.5%TD after six PIP cycles. This is a significant improvement in comparison with the literature data, 11 which reports the need for twelve PIP cycles using high-pressure impregnation to achieve the same level of density. Hence, our results clearly indicate that for full densification after PIP, a higher green density and a few additional PIP cycles would be needed.…”

“…21 Higher values can be ascribed to higher crystallinity of samples due to large amount of initial crystalline powder in the material. Lee et al 11 reported on similar thermal conductivity values (50 W/mK) for SiC p /SiC-PIP matrix, where the green parts produced by slip casting or pressing of powder and polymer mixtures samples densified after twelve PIP cycles with high pressure infiltration of polymer.…”

“…This represents a significant improvement over the recent literature report. 11 Here, the authors used the same type of polymer to impregnate slip-cast and dry-pressed green parts, but they observed highly porous regions in the central parts of the samples and dense regions near the surface, which was suggested as the main processing issue for further polymer infiltration.…”

“…In another variant of the PIP process, the green parts produced by the slip casting or pressing of powder and polymer mixtures were impregnated with polymer to fabricate a SiC p /SiC-PIP matrix. 11 This combined process was presented as a promising technique for fabricating a dense SiC-matrix; however, the impregnation with the polymer was retarded after 0955-2219/$ -see front matter © 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jeurceramsoc.2010.11.021 a certain number of PIP cycles due to the formation of a dense layer near the surface of the sample.…”

An investigation on the synthesis of borazine

“…However, it is not feasible to be prepared in forms of fibers, coatings, and complicatedly shaped bodies by conventional high temperature sintering process. Precursor derived ceramic routes provide an approach to this issue [2][3][4]. Borazine (B 3 H 3 N 3 H 3 ) is reported to be a promising precursor for boron nitride [5][6][7][8].…”