Corrosion is a major concern in almost all fields of industrial manufacturing. ALD offers a revolutionary effective way for advanced and reliable corrosion protection, either as such or combined with other thin film deposition techniques. A prime example of this is recently (August 2011) ended European Union 7th Framework Programme founded project CORRAL, where advanced corrosion protection methods were developed and ALD was proven to be superior to every other existing corrosion protection technique. Less than 0.001 % porosity of the CORRAL coatings was achieved and according to NSS (neutral salt spray) tests, their ability to seal 100Cr6 steel substrates exceeded 800 h, whilst the automotive industries' specification is only 192 h. ALD films also improve the existing coatings manufactured with other techniques, e.g. blocking the possible pinholes in them and offering structural strengthening and better chemical and thermal stability, thus increasing their lifetime by a factor of 3-10. Furthermore, ALD is the only method with which accurate tailoring of thickness and composition of the protective coatings can be achieved. Additionally, the appearance (i.e. color) and electrical properties of the coated material can be tuned through coating.
ALD corrosion protection technology is based on impermeable sealing of the material against ambient conditions by deposition of an extremely dense, pinhole- and defect-free thin film protective layer on its surface by the ALD method. The choice of the film material depends on the underlying material and the environmental properties it is exposed to. ALD results in uniform and conformal deposition of compact and high-quality thin films on all surfaces of three-dimensional components.