Protective composite coatings obtained by plasma electrolytic oxidation on magnesium alloy MA8

An improvement of the wear and corrosion resistances of AZ31 magnesium alloy by plasma electrolytic oxidation in a silicate–hexametaphosphate electrolyte with the suspension of SiC nanoparticles

“…4). For effective use of nanoparticles in electrolyte composition for PEO, it is important to control their size and ξ-potential, a negative ξ-potential for the particles is known to be helpful for the incorporation of particles into the coatings under electric filed [21]. The uniform distribution of SiC nanoparticles into the coatings may indicate that the SiC particles might have a negative ξ-potential in the present study, which is consistent with the previously measured ξ-potential value of −17 mV for SiC nanoparticles, although in a diluted electrolyte.…”

“…The SiC nanoparticles were believed to exist in the coating outer layer, however, the incorporated SiC nanoparticles have not been well characterized by XRD or by SEM, which was attributed to the small amount of SiC nanoparticles in the composite coatings. In a more recent work of Gnedenkov et al [21], ZrO 2 and SiO 2 nanoparticles have been tried for the PEO treatment of a MA8 magnesium alloy and the corrosion protection of the coatings was evaluated by electrochemical methods. It was found that the incorporation of both kinds of nanoparticles, especially the ZrO 2 , has improved the corrosion resistance of the coatings.…”

Dynamic model of single discharge during microarc oxidation

“…The processes at the interface are governed by many external factors and become even more complicated because of the mutual influence of these factors. Apart from providing the general knowledge about the potential of microarc oxidation, studies of microplasma electrochemical processes [1][2][3][4][5][6][7][8] make it possible to create models of the individual stages of this process.…”

Fabrication and characterization of hydrophobic microarc oxidation/poly-lactic acid duplex coating on biodegradable Mg–Ca alloy for corrosion protection

“…Microarc oxidation (MAO) is a chemical conversion process and is one of the most appropriate method for Mg alloys owing to its excellent abrasive resistance, enhanced corrosion resistance and high bonding strength to the substrate [3,[5][6][7]. However, MAO coating is not able to provide long term corrosion protection for Mg alloys in physiological environment owing to its porous structure [5,8]. Therefore, polymer coating have been employed to seal the pores of the MAO coating on the surface of Mg alloys [3].…”