Significance of plasma electrolytic oxidation treatment on corrosion and sliding wear performances of selective laser melted AlSi10Mg alloy

Abstract

In this investigation, Plasma Electrolytic Oxidation (PEO) process was used to prepare an alumina (Al 2 O 3 ) coating for corrosion and wear protection of a Selective Laser Melted (SLM) AlSi10Mg alloy radiator. The phase compositions, microstructures, mechanical properties, corrosion properties and wear resistance of the SLM AlSi10Mg alloy and the PEO coatings were investigated systematically. It was observed that the AlSi10Mg alloy prepared by SLM displayed a denser microstructure, finer grains and excellent mechanical properties with an average ultimate tensile strength of 402 MPa and an elongation of 9.9%. In addition, a double-layered coating with Al 2 O 3 as the top layer having a thickness of ~20 μm and a hardness of 1051HV 0.01 was realizable on the SLM AlSi10Mg alloy by PEO treatment. The corrosion current density and wear rate of the PEO Al 2 O 3 coatings were 5.7 and 279.3 times lower compared to the plain SLM AlSi10Mg alloy. The results indicate that the PEO treatment can significantly improve the wear and corrosion resistance of the AlSi10Mg alloy prepared by the SLM process. • AlSi10Mg alloy prepared by SLM exhibits dense microstructure and fine grain size. • AlSi10Mg alloy prepared by SLM process has excellent mechanical properties. • PEO film has dense outer layer and less dense inner one whose main phase is γ-Al 2 O 3. • PEO can provide excellent corrosion and wear protection for the SLM AlSi10Mg parts.