A composite anodizing coating containing superfine Al2O3 particles on AZ31 magnesium alloy

Abstract

a b s t r a c t a r t i c l e i n f o Available online xxxxAnodic coatings with and without superfine Al 2 O 3 particles were prepared on AZ31 magnesium alloy by anodizing in an environmentally friendly alkaline solution. The microstructure and morphology of the coatings were analyzed using X-ray diffraction and scanning electron microscopy equipped with energy dispersive spectroscopy. The corrosion resistance of the uncoated AZ31 substrate and the anodic coatings was evaluated in 3.5% NaCl solution through potentiodynamic polarization tests. Friction and wear tests were performed to evaluate the wear resistance of the samples. The results show that the composite oxide coating has better corrosion resistance than the coating without Al 2 O 3 nanoparticles. The microhardness of the composite coating with reinforced Al 2 O 3 nanoparticles is up to 358 HV. When rubbed at 10 N load for 3 min during sliding against GCr15 at ambient temperature, the wear loss of the film was about 0.04 mm 3 , which is about one-tenth of that of the anodizing coating without nanoparticles. Therefore, the composite anodizing coating with Al 2 O 3 nanoparticles shows better anti-corrosion and anti-wear properties than the coating without Al 2 O 3 nanoparticles.

Formation of a composite anodic oxidation film containing Al2O3 particles on the AZ31 magnesium alloy

“…Based on our previous studies, [17][18][19][20] an environmentally friendly NaOH-Na 2 SiO 3 alkaline electrolyte containing 5 g/L of sodium hydroxide, 5 g/L of ethylene diamine and tetra acetic acid, 15 g/L of phytic acid, and 120 g/L of sodium silicate was selected for the anodizing treatment in the present work. A total of 10 g/L of Al 2 O 3 particles with a mean particle size of 300 nm (Figure 1) were introduced into the electrolyte to produce the composite coatings.…”

Characterization of micro-arc oxidation coatings on Ti6Al4V with addition of SiC particle

“…Composite coatings also can be prepared by adding nano or micro size particles into the electrolytes during the MAO treatment of metals. Particles of ZrO 2 [16], and Al 2 O 3 [17] applied to the MAO treatment proved that the coatings have shown more efficient protection after the incorporation of such nanoparticles. Silicon carbide (SiC) is known for its outstanding hardness, good wear resistance, and hightemperature stability, indicating that SiC can withstand high temperature during the MAO process and be a good supporter on MAO surfaces.…”

Effect of reinforcement, compact pressure and hard ceramic coating on aluminium rock dust composite performance

“…The type of coating material depends on the application of the core material; Alumina, Boron carbide, Tungsten carbide and Titanium based coatings are commonly used and they increase the properties significantly [8][9][10][11]. Al 2 O 3 coating over the alloys increases the tribological and corrosion properties to a great extent [12]. Various methods like anodizing, spray coating are used for surface coating [12][13].…”

“…Al 2 O 3 coating over the alloys increases the tribological and corrosion properties to a great extent [12]. Various methods like anodizing, spray coating are used for surface coating [12][13]. According to Dingfei Zhang et.al anodizing is an economical, efficient and environmental friendly traditional method for such applications.…”