Effect of Pulse Frequency on Titanium Alloy Micro-arc Oxidation Coating

Oxide ceramic coatings were formed on Ti6A14V alloy surface by micro-arc oxidation (MAO) treatment in the mixture solution of Na2SiO3 and Na3PO4.The influence of pulse frequency on the coating thickness,surface morphology,phase compositions and the anticorrosive property was studied.The results show that with the increase of pulse frequency,the thickness of the coatings decreased,the size of micropores reduced,the number of micropores increased.The oxide ceramic coating was composed of anatase and rutile TiO2.When the pulse frequency was lower than 500 Hz,it had slight impact on the content of rutile and anatase TiO2.While the pulse frequency was higher than 500 Hz,the rutile TiO2 content of the oxide coating slightly increased with the increase of pulse frequency,and the anticorrosive property obviously enhanced in 30% sulfuric acid solution.