Mechanical Properties of Oxidation‐Resistant SiC/C Compositionally Graded Graphite Materials

Abstract

Mechanical properties of oxidation-resistant SiC/C compositionally graded graphite materials composed of a CVD SiC coating layer, a SiC/C graded layer, and a graphite substrate were studied by bending, compressive, and hardness tests at room temperature. CVD SiC coated graphite and graphite with a SiC/C graded layer alone were also examined. The bending strengths of oxidation-resistant SiC/C compositionally graded graphite materials as well as CVD SiC coated graphite were about twice as much as that of graphite. The bending and compressive strengths of graphite with the SiC/C graded layer alone were almost the same as those of graphite. The higher strengths of graphite with the CVD SiC layer can be mainly due to the CVD SiC strength itself, and partly due to the smooth CVD surface. No effect of the SiC/C layer on the strengths was discussed in terms of porosity, surface morphology, and the strength of SiC.

Concept of prismatic high temperature gas-cooled reactor with SiC coating on graphite structures

“…From the viewpoint of mechanical properties, a SiC layer applied with the CVD technique on either a graphite substrate or on FGM SiC/C graded material can improve the bending strength approximately twofold compared to that of bare graphite, while the FGM SiC/C grade layer did not have this effect. However, SiC coating by either technique can remarkably improve the hardness of the material (Nakano et al, 1997).…”

Formation of titanium carbide on graphite via powder immersion reaction assisted coating

“…In the recent years, there has been an increase in the actual and potential uses of graphite and carbon/carbon composites especially in high temperature applications when they may be exposed to an oxidizing atmosphere or be in contact with metal alloys [1,2]. This results in detrimental effects on carbon surfaces or carbon/metal interfaces and deterioration of mechanical properties of parts made from graphite or carbon/carbon composites [3,4].…”

Chemical Vapor Deposition of Silicon Carbide/Titanium Carbide Composite Films from Dichlorodimethylsilane, Titanium Tetrachloride, and Methane

“…Refractory coating of materials by a ceramic film is an important application of CVD processes, which is a key technology for producing industrial materials with improved energy efficiency, corrosion resistance, mechanical smoothness, surface electric conductivity, etc. The film qualities needed to satisfy these tough specifications spurred the research and development of coatings with multicomponent ceramics, such as SiC/C [8][9][10] and SiC/TiC. 11,12 The CVD processes for multicomponent coatings often use multiple precursors.…”