CVD coatings are thin films resulting from the chemical reaction between a gaseous phase and the heated surface of a substrate. Among the industries using CVD coating technology are electronics, tooling, fuel cogeneration, and aerospace. The electronics industry uses CVD to deposit semiconductor materials onto different substrates. For the tooling industry, titanium nitride (TiN), titanium carbide (TiC), or aluminum oxide (Al2O3) is deposited onto cutting or metal forming tools. These hardcoatings act as chemical and thermal barriers between the tool and workpiece.
In the aerospace industry, CVD is used to deposit aluminide or chromide coatings onto jet engine blades and other hot section components. The coatings improve the corrosion and oxidation resistance of the base metal. CVD is replacing older established methods for protecting these same components. While the use of CVD coatings in the aerospace industry is relatively new, it is gaining increasing acceptance. In addition to producing aluminides and chromides, CVD reactions can form coatings containing silicon, yttrium, hafnium and other rare earth elements. Since the coatings are the result of the chemical reaction between high purity gases and solids, coatings can be free of porosity and inclusions.