Silicon steam corrosion resistant internal coating for directly protecting carbon fiber and in-situ preparation method thereof

Abstract

The invention relates to a silicon steam corrosion resistant internal coating for directly protecting carbon fiber and an in-situ preparation method thereof. The internal coating is prepared by the following steps of: coating a primary pyrolytic carbon substrate layer on the surface of carbon fiber through a chemical vapor deposition mode; then coating a secondary silicon carbide enriched protective layer on the surface of the primary pyrolytic carbon substrate layer through the chemical vapor deposition mode. The invention further relates to a preparation method of the silicon steam corrosion resistant internal coating for directly protecting the carbon fiber. The silicon steam corrosion resistant internal coating obtained by the invention is compact and uniform in structure, is firmly bonded with a carbon fiber body in a carbon / carbon composite material crucible and completely coats the carbon fiber body; and a carbon fiber reinforcing material of the carbon / carbon composite material crucible with the silicon steam corrosion resistant internal coating is not corroded by silicon steam, thus the use reliability of a product is improved, and the service life of the product is prolonged.

Description

technical field [0001] The invention belongs to the technical field of chemical vapor deposition, and relates to an anti-silicon vapor erosion inner coating for directly protecting carbon fibers and an in-situ preparation method thereof. technical background [0002] Carbon fiber reinforced carbon-based composites (referred to as carbon / carbon) have outstanding characteristics such as low density, high strength, fast heat conduction, high high temperature strength retention, high sublimation temperature and high purity, and have been widely recognized in the high temperature industry. Applications, especially in the fields of smelting and purification of silicon materials, ingot casting, and single crystal drawing. However, in carbon fiber-reinforced carbon-based composites, carbon matrices such as pyrolytic carbon, resin carbon, and pitch carbon are all carbon materials, which cannot effectively protect carbon fibers. During high-temperature service, the ambient atmosphere ...

AI Technical Summary

Problems solved by technology

However, these traditional methods have some outstanding problems when preparing silicon carbide coatings on the surface of carbon fibers in carbon / carbon composite crucibles: 1. Density, silicon carbide coatings prepared by traditional processes are difficult to be completely dense; 2. Bonding strength , due to the difference in thermal expansion properties between silicon carbide and carbon fiber, the silicon carbide coating prepared by the traditional process is often easy to crack and fall off from the surface of the carbon fiber. 3. Coating integrity, the silicon carbide coating prepared by the traditional process has coating Defects of uneven coverage and residual blanks

Images