AVS 58th Annual International Symposium and Exhibition
    Advanced Surface Engineering Division Wednesday Sessions
       Session SE+PS-WeA

Paper SE+PS-WeA4
In Situ Fabricating Blue Ceramic Coatings on Al Alloy by Plasma Electrolytic Oxidation

Wednesday, November 2, 2011, 3:00 pm, Room 104

Session: Atmospheric Pressure Plasmas
Presenter: Zhijiang Wang, University of Windsor, Canada
Authors: Z.J. Wang, University of Windsor, Canada
R.O. Hussein, University of Windsor, Canada
X. Nie, University of Windsor, Canada
H. Hu, University of Windsor, Canada
Correspondent: Click to Email
In-situ formation of novel blue ceramic coatings on Al alloy with a controllable blue color was successfully achieved using a plasma electrolytic oxidation (PEO) process working at atmospheric pressure. This novel blue ceramic coating overcomes the shortcomings of surface treatments resulting from traditional dyeing process by depositing organic dyes into the porous structure of anodic film, such as poor resistance of abrasion and rapid fading when exposed to light. X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy were employed to characterize the microstructure of the blue ceramic coating. The main compositions of the coating are CoAl2O4 and Al2O3. This work shows that the working current density plays significant roles on CoAl2O4 phase in the ceramic coating which has a controllable influence on the coating color. Low current density reduces the percentage of CoAl2O4 component in the coating, and light blue ceramic is produced. On the other hand, higher current density increases CoAl2O4 component in the coating, hence deep blue ceramic is fabricated. Electrochemical test, ball-on-plate sliding wear tester and thermal shock method were utilized for the corrosion, wear and thermal shock resistance analysis of the fabricated ceramic coatings. The results indicate that the developed blue coating via PEO process superiorly improves the tribological property, anti-corrosion property and thermal shock resistance. The fabricated blue ceramic coating tends to be applied to colored light cast alloys for applications used in relatively harsh and severe working environments.