Preparation of SiC-based cellular substrate by pressure-pulsed chemical vapor infiltration into honeycomb-shaped paper preforms

Author： Ohzawa Y. Nakane K. Gupta V. Nakajima T.

Publisher： Springer Publishing Company

ISSN： 0022-2461

Source： Journal of Materials Science, Vol.37, Iss.12, 2002-06, pp. : 2413-2419

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Abstract

Using a pressure-pulsed chemical vapor infiltration technique, SiC was infiltrated from a SiCl_4 (4%)–CH_4 (4%)–H_2 gas phase into carbonized paper preforms at 1100°C. SiC-based cellular substrates with cell wall thicknesses of 25, 50 and 100 μm were obtained by using honeycomb-shaped paper preforms as the templates. The reduction of both wall thickness t and cell pitch d of SiC-based honeycomb substrate successfully led to an increase in geometric surface area per unit volume S, keeping pressure drop ΔP at constant, besides; ΔP decreased without lowering S by the reduction of t and the increase in d. The pressure drop in the prepared honeycomb substrates depended on S^2α^−3 value, where α was open frontal area fraction. The compressive strength of the honeycomb substrates with t of 25 μm was about 7 MPa. The strength increased in proportion with 1 - α, which corresponded to the volume fraction of the cell wall in the honeycomb substrate.