IMPROVED PACK MIXTURE COMPOUND FOR CARBURIZATION COATING OF SILICON CARBIDE PACK AS CARBONACEOUS BASE MATERIAL

摘要

PURPOSE: To form the pack mixture composition useful for coating a carbonaceous substrate by blending Si, B, SiO₂ and SiC in a specified ratio in order to prevent a carbonaceous substrate from degradation due to oxidation at a high temp. ;CONSTITUTION: The pack mixture composition contains respective components of (a)-(d) in the following and is useful in forming SiC pack cementation coating in order to prevent a carbonaceous substrate from degradation at a temp. exceeding about 800°F. The composition consists of, in a ratio to a total weight of the composition, (a) about 15-50% Si, (b) 0-about 25% B, (c) about 0.01-3% SiO₂, (d) about 40%-85% SiC. Forming SiC pack cementation coating is conducted on a carbonaceous substrate so that (1) the pack mixture composition containing the (a)-(d) components is produced, (2) a release material is coated on a carbonaceous substrate (a cork is preferably), (3) a release material coated carbonaceous substrate is surrounded with the pack mixture composition, (4) the carbonaceous substrate is fired at about 2900-3300°F for about 4-16 hr.;COPYRIGHT: (C)1991,JPO