Abstract
Titanium (Ti) is active metal. However, Ti has an ability to protect itself against chemical attack by a passive oxide film. The nature of the oxide film is an important factor in determining chemical reactions of Ti. Pure Ti was annealed in ambient air at 800℃. The oxide films of the specimens were removed by abrasion. The specimens were immersed in a mixed solution of NaF and H3PO4 (APF). The effect of oxide films on degradation of Ti in APF solution was measured by a thermal desorption spectrometer (TDS). The dislodgement of ions from the specimens during heating was detected. The amounts of released hydrogen were estimated for the specimens with the heat and the immersion treatments. The oxide films were an effective factor in determining the degradation of Ti in the APF solution. The TDS method was a useful technique for identification of the absorbed molecules.
