Influence of SiO2 Particles on the Corrosion and Wear Resistance of Plasma Electrolytic Oxidation-Coated AM50 Mg Alloy

Abstract

The influence of SiO2 particles on the microstructure, phase composition, corrosion and wear performance of plasma electrolytic oxidation (PEO) coatings on AM50 Mg was investigated. Different treatment durations were applied to fabricate coatings in an alkaline, phosphate-based electrolyte (1 g/L KOH + 20 g/L Na3PO4 + 5 g/L SiO2), aiming to control the incorporated amount of SiO2 particles in the layer. It was found that the uptake of particles was accompanied by the coating growth at the initial stage, while the particle content remained unchanged at the final stage, which is dissimilar to the evolution of the coating thickness. The incorporation mode of the particles and phase composition of the layer was not affected by the treatment duration under the voltage-control regime. The corrosion performance of the coating mainly depends on the barrier property of the inner layer, while wear resistance primarily relies on the coating thickness.

The Effect of Electrolytic Solution Composition on the Structure, Corrosion, and Wear Resistance of PEO Coatings on AZ31 Magnesium Alloy

“…By altering frequency to 2 kHz in the second half cycle, cell current density remains constant for all electrolyte types (1.8 A dm −2 ) and does not change. Applying a higher frequency decreases the life span of discharges that neutralizes the orange-colored sparks and helps prevent intense breakdowns at the final stage [33].…”

“…As sliding continues, generated debris fills the larger-sized flaws, and the rest of the spalling particles engage in the wear process as third-bodies [29,50]. The literature [33,50] supposed third-body abrasion is the main wear mechanism in PEO coatings.…”

“…As sliding continues, generated debris fills the larger-sized flaws, and the rest of the spalling particles engage in the wear process as third-bodies [29,50]. The literature [33,50] supposed third-body abrasion is the main wear adhesive wear when the ball touches the substrate in Si specimen, which is consistent with previous studies [29,32,50]. The wear rates are calculated by taking into account the worn volume, applied load, and the test distance for a better comparison of coatings, and the results are illustrated in Figure 10.…”

Fabrication of High Temperature Oxidation Resistance Nanocomposite Coatings on PEO Treated TC21 Alloy

“…In this process, the type and concentration of nanoparticles directly affects the properties of the coatings. The most commonly added particles are various oxides including TiO 2 [20], Al 2 O 3 [21], ZrO 2 [22], SiO 2 [23], CeO 2 [24], and La 2 O 3 [25]. The particles can achieve either reactive or inert incorporation into the coating while imparting excellent properties to the coating.…”

Production of Phosphorescent Coatings on 6082 Aluminum Using Sr0.95Eu0.02Dy0.03Al2O4-δ Powder and Plasma Electrolytic Oxidation

“…Metal alloys such as aluminum or magnesium are widely used in automotive [17], aerospace [18], and aviation industries because of their light weight and ease of workability. Despite being mostly used for enhancing the wear and corrosion resistance properties of metals [19,20], the PEO method has proven to be useful for creating functionalized coatings, and in the last few years, there has been a growing amount of research devoted to studying these prospects. PEO has been used for producing photocatalytic [21], gas sensing [22], and dosimetric [23] coatings as well as coatings for biomedical applications such as dental [24] and orthopedic implants [25].…”