The effect of oxidation time on the micro-arc titanium dioxide surface coating containing Si,Ca and Na

Alkaline electrolyte containing Si, Ca and Na elements was used to make porous coating of titanium dioxide on the titanium matrix surface by the way of micro-arc oxidation (MAO). The influences of MAO time on the microstructures and the distribution of elements in the coating surface was investigated. The results showed that the coating surface contains Ti, O, Si, Ca, Na. The contents of Si, Ca, and Na elements increase with the increasing of MAO time. After the MAO time reaches 10 minutes, the increasing speed of elements content decreases. The pore size of the coating surface is in direct proportion to the MAO time. The number of pores is in inverse proportion to the MAO time. After the MAO time reaches 5 minutes, the pore size increasing speed and the number of pores decreasing speed weaken.