PURPOSE: To obtain a dense composite material having little residual voids in a short time by applying a temperature gradient to a porous formed article to get a high inner temperature and low surface temperature, supplying a gaseous raw material to the gap of the article and slowly performing a solid-forming reaction from the inner side.
CONSTITUTION: A porous formed article 16 is placed in a reaction zone 11 of a reactor 2 placed in a vacuum vessel 1. The formed article 16 is heated from inside by microwave generated by a microwave oscillator 3 and, at the same time, the surface of the article 16 is cooled with a cooling medium flowing a cooling channel (a) to apply a temperature gradient to the formed article 16 to get a high inner temperature and low surface temperature. A gaseous raw material is introduced through a gaseous raw material feeding pipe 15 into the reaction zone 11, permeated into the gap of the formed article 16 and slowly subjected to a solid-forming reaction from the inner side of the formed article 16 heated at a high temperature, A matrix layer is slowly formed from the inner side and is extended gradually to the surface side to fill the gap with the matrix layer and obtain a composite material having small residual void content.
KOGA ARATA
ISHIZAKI MASAHITO
MIYAHARA KAORU
