A REVIEW ON HIGH TEMPERATURE OXIDATION RESISTANT COATINGS PREPARED BY SOL - GEL PROCESS

Sol - Gel processing is one of the simplest techniques for preparation of compound coatings. Continuous coatings of SiO2Al2O3ZrO2 and their compounds can be prepared by Sol - Gel process on different substrates. In this paper, the characters and principle of Sol - Gel process and the technological process of the Sol - Gel derived high temperature oxidation resistant coatings have been introduced systemically, and the disadvantages of this technique have also been pointed out. It is suggested that the adherence strength between the coatings and substrates and cracking of the coatings should be investigated emphatically in the future. And Si - C - N coating derived from a novel non ?oxide Sol ?Gel processing has been introduced briefly.