Ion Release of Passivated Ti-6Al-4V：Effect of thickness and phase of TiO2 film

• Main Authors: Chung Ping Chao, 趙崇斌
• Other Authors: Edward Chang
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/26707864468698339559

碩士 === 國立成功大學 === 材料科學及工程學系 === 87 === Abstract In orthopaedic surgeries, metals are often used, however, when placed in a physiological environment, metal ions are released with potentially harmful local and systematic effects. In application, a tenacious oxide film of TiO2 , formed spontaneously either as anatase or rutile phase on the surface of titanium and its alloys, will be conducive to the reduction of ion release. Previous study reported that a heat treatment at 400℃for 45 min of the nitric acid passivated Ti-6Al-4V alloy significantly reduced the ion release, however, the factor contributing to the improvement were uncertain. The present research aimed to study the individual and combined effects of phase and thickness of TiO2 oxide film on the ion release of the Ti-6Al-4V alloy. In part I of the experiments, TEM was used to examine the phase of oxide film of the 33﹪nitric acid passivated material vacuum heat treated at 400℃and 700℃, or air heat treated from 25℃to 400℃. Also, XPS method was employed to measure the thickness of the oxide film. In part II of the experiments, ion release of the differently treated materials was measured by ICP analysis. Within the experimental range studied, the study indicated that the rutile phase of TiO2 on the surface of passivated Ti-6Al-4V plays a major role, while the thickness of oxide is secondary, in contributing to the repress ion of ion release in a physiological environment. Simultaneous controls of phase and thickness of TiO2 oxide will additively contribute to the reduction of ion release.