| 摘要 |
<p>PROBLEM TO BE SOLVED: To form an SiC-C mixed layer in the surface layer part of a carbon substrate in a single process only by pressure control and to form a dense SiC coating film on the mixed layer by controlling the internal pressure of a reactor so that the pressure in the 2nd half of chemical reaction allowed to proceed in a one-cycle heating process in the presence of gaseous SiC and gaseous CO is made lower than that in the 1st half. SOLUTION: Gaseous SiO and gaseous CO are generated by allowing metallic Si to react with carbon oxide or carbon to react with SiO2 . Since the internal parts of a high-temp. reactor are made of an ordinary carbon material, nitrogen oxide may be used in place of the carbon oxide. The surface roughness Ra of a carbon substrate is regulated to 5-15. The internal pressure of the reactor is controlled so that the pressure in the 1st half of reaction allowed to proceed in a one-cycle heating process is regulated to 9-250Torr and that in the 2nd half to 1-8Torr. The internal temp. of the reactor during the reaction is 1,773-2,073K. The pressure control is carried out in accordance with standard data of the carbon substrate.</p> |
