A deposition process in which a source material in the form of an ingot (or rod) is vaporised through the bombardment of an electron beam from a tungsten filament charged under high vacuum and re-solidifies as a coating on a target surface. Deposition rates can range from a few nm per minute to several µm per minute enabling control of the coating structure and morphology. PVD methods are typically either ‘line-of-sight’ or ‘semi-line-of-sight’ and utilise electron beam guns with power levels of a few 10s to 100s of kW. Rotation and translational of the target substrate assists the uniform coating of the outer surface of complex geometries.
EB-PVD is the preferred process for the generation of thermal barrier coatings (TBC) in jet engines. As the name suggests the TBC provides a layer of thermal insulation on the turbine blade enabling the blade to run cooler for an identical turbine entry temperature or reducing the need for blade cooling whilst maintaining its creep life.