Thin film deposition with a cold atmospheric pressure plasma jet for corrosion protection of aluminum and for tailoring adhesion properties

摘要

Thin film deposition at atmospheric pressure with high deposition rates is of great interest for industrial plasma-based applications. In this study thin films were deposited on aluminum with a cold atmospheric pressure plasma jet using hexamethyldisiloxane (HMDSO) as precursor. A very high dynamic deposition rate on the order of 450 nm m min~(-1) was achieved. Composition and structure of the thin films show a strong dependence on the downstream location of the precursor injection. This effect is related to the fast relaxation of the plasma in the transition region to the afterglow where the precursor is injected. The use of different coatings for corrosion protection, adhesion promotion, or low-adhesion applications is studied. The coatings provide good corrosion resistance to aluminum 2024 for more than 96 h in a neutral salt spray test and improve the adhesive bond strength of aluminum/epoxy joints strongly.