PURPOSE: To obtain a carbon material coated with boron carbide having excellent thermal shock resistance by forming a gradient-functional boundary region having a specific thickness between a boron carbide layer and a carbon material as a base.
CONSTITUTION: A carbon material is arranged in a high-frequency induction furnace and an argon gas and a boron oxide gas are introduced to the high-frequency induction furnace while heating the carbon material at 1,600-2,100°C to convert the surface of the carbon material into boron carbide and form a boundary region continuously reducing boron and increasing carbon from the side of a boron carbide coating film to the side of the carbon material in ≥20μm thickness. The method for thickening both the boron carbide layer and the boundary region is preferably carried out by firstly forming the boron carbide layer at a temperature of >2,100°C, then lowering to 1,600-2,100°C to form the boundary region.
| WO/2000/045621 | CARBON-BASED HEATING UNIT AND METHOD FOR PREPARATION THEREOF |
| WO/2019/065018 | GRAPHITE MATERIAL |
| JPH0635324 | [Title of Invention] Method for producing glassy carbon |
KIKUCHI YOSHIHIRO
HYAKKI YASUO
