Abstract:

By using a unipolar multifunction pulse power supply, titania films with micropores and micrograins were prepared by microarc oxidation of titanium alloy in a Na₂CO₃ and NaOH electrolytic solution under the condition of the constant pulse current density and frequency of 20A/dm² and 5000Hz. XRD and SEM were employed to characterize the phase component and surface morphology of the films. The experimental results show that (1) the film consists of rutile and anatase phases, and the content of rutile increases with the increasing treatment time; (2) the coating surface is porous and has a large number of micrograins sized from 300nm to 1μm, and the sizes of the micrograins and micropores increase gradually, with the increasing time, while their densities decrease by degrees.

Key words: microarc oxidation, titanium alloy, phase component, surface morphology