| The growth process of ceramic coatings formed by micro-arc oxidation on titanium alloys were studied by the analysis of the surface and sectional pattern for ceramic coatings that treated by different electrical parameter. The factors investigated which influenced the ceramic coatings on surface morphology were analyzed consequently. And phase constituents of ceramic coatings were investigated using X-ray diffractometer. The bonding strength and the tearing state of different surface morphology for ceramic coatings/epoxy resin were studied , fuermore, conclued and analysis the correlative factors which influenced the bonding strength of the interface to coating/epoxy resin.The results indicate that the choice and control of electrical parameter play a key role in the surface morphology and growth of ceramic coatings. With the prolonging oxidation time the micropores number on the surface of the coatings decreases obviously, while the size and the deviation of micropores increases under constant electrical parameters. The current density ., voltage and duty cycle have a influenceing rule to morphology of ceramic coatings as same as oxidation time .As the frequency increased, the micropores number on the surface of the coatings increases , the pores size and the deviation of micropores decreased, so did the surface roughness. The bonding strength of coating/epoxy resinincreased with increasing frequency, and reached a maximum value of 66.05 MPa at 400Hz, then decreased gradually up to a relative stable value. As the relative content for rutile and anatase TiO2 increased, the bonding strength of coating/epoxy improved. The more content of rutile TiO2 in coatings , the best of bonding strength of coating/epoxy is. The solidification time and thickness of epoxy resin, the 30mm circular column of titanium grit blast and ultrasonic cleaning or not are all impact the bonding strength of coating/epoxy. |
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