Microstructure characterization and corrosion resistance evaluation of titanium anodized at different voltages

Abstract

Titanium has been perceived as a good alternative for marine and biomedical applications due to its high compatibility with the human body, strong material characteristic and ability to hinder corrosion. However, at certain condition such as temperature above 80℃, titanium is still prone to crevice corrosion. As a result of its high functionality, a lot of researchers have been researching on the corrosion resistance of titanium before and after surface treatment in different environment. Different titanium alloy have also been studied to understand their corrosion resistance ability and their physical strength. As a result, this project will focus on the corrosion behavior of anodized titanium at different potentials, 50 V, 100 V and the 200 V, in sodium chloride, NaCl, solution to simulate a seawater environment.

In this project, pure titanium will first undergo anodizing at 50 V, 100 V and 200 V where titanium dioxide will form. A series of immersion test in NaCl under high pressure and temperature of 160℃ will be used to simulate a high temperature seawater environment. The thickness of the oxide will also be accessed and measure using calotest, while the wear area will be measured and observe using ball-on-disk tribometer and the Alpha IQ surface profiler. Scanning electron microscopy, SEM, and X-ray diffraction, XRD, will also be use to study the surface morphology and the phase structure of anodic titanium dioxide layer, anatase and rutile layers, before and after immersion test. In addition, the anodized titanium will undergo a series of electrochemical corrosion test using the galvanostat operating at a potential of 10mV. This investigation will help to explore potential methods for corrosion resistance enhancement of titanium for offshore engineering applications.