Black and gray microarc oxidation (MAO) coatings were prepared in a phosphate electrolyte with and without K2TiF6 on 2A70 aluminum alloy, respectively. Voltage-time curves were recorded during the MAO process. The effects of K2TiF6 on the morphology, composition, abrasive resistance and corrosion resistance of MAO coatings were investigated. The results showed that the MAO coating produced in the electrolyte with K2TiF6 was thicker, and more uniform than that produced in the electrolyte without K2TiF6. Ti was detected in the surface of the MAO coating formed in the electrolyte with K2TiF6. The results of abrasive resistance and corrosion resistance showed that the MAO coating formed in the electrolyte with K2TiF6 exhibited better abrasive resistance and corrosion resistance. (C) 2012 Elsevier B.V. All rights reserved.