Surface adhesion enhancement of anodized A5052 aluminum alloy with low-power atmospheric pressure plasma jets in order to recover wettability

We focused a low-power atmospheric pressure plasma jet (APPJ) on a specimen of anodized A5052 aluminum alloy with degraded surface wettability due to atmospheric exposure for more than 30 days. We show that an APPJ driven at about 10 W of power can restore surface wettability. To demonstrate this, specimens were irradiated with an APPJ using He as the carrier gas at a scanning pitch of 1 mm, a scanning speed of 10 mm/s, and a working distance of 20 mm between the glass tube and the specimen surface. Compared to the sample immediately after anodizing, the irradiated surface was found to have equivalent hydrophilicity, 88% of the fracture load in the tensile shear test, and 2% change from X-ray photoelectron spectroscopy (XPS) analysis of C and O on the specimen surface. Thus, short APPJ irradiation is effective in enhancing the surface wettability of specimens that have been exposed for more than 30 days from anodization. Furthermore, the surface modification technique attempted in this study can be applied to a wide range of multi-materials to enable the joining of dissimilar materials.