Simulated Body Fluid Immersion of Calcium- and Phosphorus-containing Anodic Titanium Oxide Film

• Main Authors: Daniel Mao-Teh Chen, 陳懋德
• Other Authors: Chao-Sung Lin
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/97711315351003674630

碩士 === 國立臺灣大學 === 材料科學與工程學研究所 === 95 === Anodic oxidation of titanium in the solution containing calcium and phosphorus compounds can prepare a calcium- and phosphorus- containing oxide film. However, during the galvanostatic anodizing process, a porous inner layer formed prior to sparks and a crater-containing overlay formed with sparks resulted in decrease the adhesion of the anodic film. Calcium and phosphorus were predominantly incorporated in the porous overlay, in which the amorphous region contained more calcium and phosphorus than the crystalline region regardless of the anodizing voltages. Moreover, the ratio of amorphous to crystalline regions in the porous overlay changed insignificantly with anodizing voltage. Therefore, higher anodizing voltage can enhance the calcium and phosphorus contents in the anodic film, yet leads to the adhesion decrease problem. Simulated body fluid (SBF) is an unstable solution with some supersaturated calcium phosphate salts. Pure titanium plates and anodized titanium plates were immersed in SBF, and a layer mainly containing calcium and phosphorus was precipitated on them. The chemical properties of both pure titanium and the anodic film were herein enhanced. The time-consuming SBF precipitation process can be adjusted by alkali- and heat-treatment (AHT) before SBF immersion. Both the AHTed titanium and the anodic film resulted in forming a high-pH zone in the SBF medium, and further accelerated the precipitation process in SBF. Properties of the multi-layer structure on titanium were determined by SEM, cross-sectional TEM, EDS, XRD and the adhesion test in this study.