Enhancing compressive properties and sound absorption characteristic of open-cell Mg foams through plasma electrolytic oxidation treatment

Abstract

Plasma electrolytic oxidation (PEO) technology was used to deposit a ceramic coating on the strut of open-cell Mg foams. In this experiment, the microstructure, the phase composition, and the elemental distribution of the PEO-coated Mg foams were investigated. Effect of the PEO treatment on the compressive properties and the sound absorption characteristic of open-cell Mg foams were studied. The experimental results indicate that PEO coating is mainly composed of a mixture of MgO and MgAl2O4 ceramics with high hardness and high brittleness. The compressive strength and the energy absorption capacity of Mg foams improved after being subjected to PEO treatment; however, the brittleness of the PEO-coated foams was more noticeable than that of the uncoated foams. The sound absorption coefficient of the PEO-coated Mg foams is slightly greater than that of the uncoated foams, which is mainly attributed to increased viscous friction induced by the micro-pores in the PEO coatings.