CVD coatings are deposited out of gaseous, slightly volatile metal compounds (Chemical Vapor Deposition). This permits coating of internal surfaces as in tubes or in cooling channels of turbine blades with complex geometries.

Turbine blades require an aluminide (= aluminum diffusion coating) for protection against oxidation and hot corrosion. This coating is generated by deposition of aluminum and diffusion into the substrate. The thickness of this diffusion coating is in the range of 20µm-150µm; thus, selective coating is possible.

Using the pack aluminizing process the reaction takes place in a powder mixture which is in contact with the component, while with the CVD coating process the coating gas is generated outside the reactor and is transferred to the substrate surfaces by a carrier gas.

CVD Equipment

• High performance CVD Aluminizing System for coating internal and external surfaces of turbine blades
• Second retort for continuous operation and increased output
• Working load volume 600 liter 
• Internal generators for high activity processes 
• Separate lines for internal and external coating