Effect of rare earth Y2O3 on the corrosion and friction properties of Al2O3 ceramic coatings prepared via microarc oxidation
Yu Guo, Zhu Xue, Gang Li, Ruiwen Xu, Xiaofeng Lu
Abstract
Rare earth Y 2 O 3 /Al 2 O 3 ceramic coatings were prepared on 6063 aluminum alloy via micro-arc oxidation. The corrosion and friction properties of the substrates were enhanced. Scanning electron microscopy results showed that the number of “crater” holes increased and decreased, and the diameter of micropores first increased and decreased. X-ray diffraction results indicated that the coatings mainly consisted of α-Al 2 O 3 , γ- Al 2 O 3 , and Y 2 O 3 . The Y 2 O 3 contents gradually increased with the increase in Y 2 O 3 concentration. The surface roughness of the coatings first increased to 3.231 μm and decreased to 2.404 gm, whereas the thickness increased from 17.8 μm to 22 μm with the increase in Y 2 O 3 concentration. Results showed that the surface hardness improved to 596.9 Hv, and the corrosion current decreased to 1.133e -008 A at Y 2 O 3 concentration of 3 g/L. The friction coefficient decreased to 0.42 at Y 2 O 3 concentration of 2 g/L.