Effects of Pulse Current on the Anodic Spark Oxidized Titanium

Objectives: This study evaluated the surface characteristics of the anodic oxide layer and the hydrothermal treatment layer, and the effect of the pulse current on the characteristic of the oxide layer. Methods: Electrochemical treatments were performed while applying a direct current, the pulse current, and a reverse pulse current during anodic spark oxidation. A mixed solution of 0.015M DL-a-GP (DL-a-Glycerophosphate Disodium salt) and 0.2M CA (Calcium Acetate) was used as the electrolyte. And the anodizing voltage was set with 280V and 320V. After Anodic spark oxidation, hydrothermal treatment was performed at 300°C for 2 hours. Results: On the surface of the anodic oxide layer, micropores < 3 mm in diameter were distributed homogeneously. A mixture of polygonal shaped and thin needle shaped crystals were precipitated on the hydrothermal treatment layer produced by the pulse current treatment group. A pattern of significantly increased cell viability was observed compared with the untreated group, and the hydrothermal group showed a result similar to the untreated group. HA layers were formed on the modified surface immersed in the simulated body fluid over a 4-week period, and the surface treated by the pulse current at 320 V showed the highest activity. Conclusion: The results of this evaluation indicate that anodic spark oxidized titanium by applying pulse current has the better compatibility compare to surface by direct or reverse pulse current. This work was supported by grant No. R01-2004-000-10545-0 from the Basic Research Program of the Korea Science & Engineering Foundation. This work was supported by the Korea Science and Engineering Foundation(KOSEF) grant funded by the Korea government(MOST) (No. R01-2005-000-10461-0).