Doctoral defence: Maido Merisalu “Nanostructured coatings for car and aerospace industries”

On 8 December at 16:15 Maido Merisalu will defend his doctoral thesis “Nanostructured coatings for car and aerospace industries”.

Supervisor:
Professor emeritus Väino Sammelselg, University of Tartu

Opponents:
Dr. Marianna Kemell, University of Helsinki (Finland)
Dr. Arvo Mere, Tallinn University of Technology 

Summary
Aluminum alloys are widely used for manufacturing components in aerospace and automobile industries. Aluminum alloys are favored in these applications as they have light weight and superior mechanical properties but are also easy to process. However, these alloys are vulnerable to corrosion, which can be mitigated by using various protective coatings. The primary challenge with aluminum alloys in practical applications is the protection of high precision substrates that may also have a sophisticated three-dimensional shape or contain threaded cavities. This problem was addressed in this study, where the use of nanometric protective coatings was investigated. For that purpose, atomic layer deposition technique was used to grow various ceramic materials onto the aluminum alloy substrates that had received different pre-treatments. During these systematic studies, a technique was developed for the preparation of a novel nanostructured coating which protected the aluminum alloy against corrosion in salt spray tests. The novel coating also suffered only negligible damage from energetic atomic oxygen, which was used to simulate 1 year of exposure to space in low Earth orbit. Finally, the novel nanostructured coating was successfully applied on over 50 aluminum parts of satellite WISA Woodsat and will also be tested soon in space on the materials testing module on ESTCube-2.