Effect of SiC addition in electrolyte on the microstructure and tribological properties of micro-arc oxidation coatings on Al-Mg-Sc alloy

Abstract

Hard and wear-resistant ceramic coatings with SiC nanoparticles were in situ fabricated on Al-Mg-Sc alloy using micro-arc oxidation (MAO) method in alkaline silicate electrolyte. The microstructure, roughness, and composition of the MAO coatings were characterized by scanning electron microscopy (SEM), x-ray diffraction (XRD) and laser scanning confocal microscopy (LSCM), respectively. The microhardness of the MAO coatings was obtained microhardness tester. The wear resistance of the MAO coatings was evaluated by ball-on-disc reciprocating tribo-tester. The results showed that the phase composition of the obtained coatings with the typical pancake-like stacking structures was mainly composed of α-Al 2 O 3 and γ-Al 2 O 3 . the porosity and roughness gradually decreased with the increment of SiC nanoparticles concentration. Al content gradually decreased from the matrix to the outside, while the Si content gradually increased. The incorporation of SiC nanoparticles further increased the microhardness of the MAO coating. Especially in alkaline silicate electrolyte with 1.5g l −1 SiC nanoparticles, the microhardness could reach 1270 HV 0.5 . The friction coefficient of the MAO coatings prepared in electrolyte solution with SiC addition varied from 0.4 to 0.55, and the ceramic coating with 1.5g l −1 SiC nanoparticles exhibited the best wear resistance. The wear mechanism was attributed to be the combination of abrasive wear, adhesive wear and oxidation wear.

Effects of nano-SiO2 particle addition on the structure and properties of micro-arc oxidation ceramic coatings on 7075 aluminum alloy

“…The primary factors influencing the performance of MAO ceramic coatings produced by MAO include the composition of the electrolyte and electrical parameters (Qi et al , 2021; Zhai et al , 2022; Ma et al , 2022). Currently, by incorporating nan-particles into the electrolyte through the MAO process, high-performance nano-composite ceramic coatings can be fabricated (Wu and Jiang, 2021; Lu et al , 2019). Venugopal et al (2012).…”

Effect of Na2SiO3 concentration on corrosion resistance and wear resistance of MAO ceramic film on the Al‐Mg‐Sc alloy

“…Al-Mg-Sc alloy, a new generation of lightweight, highstrength, corrosion-resistant, and weldable structural materials for aerospace and aviation, 1 was mainly applied for the welded load structures of manned spacecraft. 2,3 Although Al-Mg-Sc alloy was very stable under normal conditions owing to the oxide passivation layer formed in air, this thin film could not provide sufficient corrosion resistance and wear resistance for some aviation components under severe service environment. Al-Mg-Sc alloy substrate could not be protected over a long period of time, and it was impossible to satisfy the desired requirements in severe environmental conditions.…”

Effect of current density on tribological properties of micro-arc oxidation ceramic film on Al-Mg-Sc alloy

“…Aluminum alloys were widely used in civil and aerospace fields owing to its low density, high specific strength and high specific stiffness [1,2]. For example, Al-Mg-Sc alloy with light weight, high strength and weldability could be used to manufacture structural parts of the re-entry module [3,4].…”

“…Jiang et al prepared ceramic film on the aluminum alloy surface through MAO, embedded SiC nanoparticles into the porous and loose outer layer, and significantly improved the wear resistance of aluminum alloy through the combination of ceramic film and nanoparticles. In addition, the thicker the ceramic, the better the wear resistance [16]. However, the effect of current density on the Al 2 O 3 ceramic film prepared on Al-Mg-Sc alloy by MAO had not been reported yet.…”