Surface modifications of aluminium and aluminium oxide induced by a treatment with a He-plasma jet and plasma electrolytic oxidation

Abstract Erosion of an aluminium oxide surface as well as a formation of an aluminium oxide coating on an aluminium substrate, comparable with erosion and oxide formation induced by plasma electrolytic oxidation (PEO), can be caused at atmospheric pressure conditions by a DBD-like (dielectric barrier discharge) plasma jet. Obtained experimental results conform a previously assumed similarity of the erosion mechanisms induced by the atmospheric pressure DBD-like plasma jet and PEO microdischarges. The mechanism of a predominantly inward growth of the oxide layer during PEO processing is substantiated based on a comparison of aluminium oxide erosion and oxide layer deposition by a treatment with the considered He-plasma jet and a PEO process.