Characteristics of Colored Passive Layers on Titanium: Morphology, Optical Properties, and Corrosion Resistance

Abstract

Electrochemically formed colored passive layers on titanium and their optical, surface morphology, and corrosion properties are presented and discussed. With the application of progressively higher AC voltages (VAC) during preparation of these passive layers, they are found to become more protective of the underlying metal, as determined from corrosion resistance measurements employing electrochemical polarization curve and inductively coupled plasma mass spectrometry experiments. The passive layers on titanium were found to be uniform in their surface morphology with no apparent cracks or pits. Surface morphology, and its relation to optical properties, was also investigated using visible light microscopy, profilometry, and near-infrared ultraviolet visible reflectance spectroscopy measurements. A correlation between the light reflected from the entire sample surface and the coloration of surface grains was also observed through these measurements. The reflectance spectra showed a red-shift of wavelength maxima (λmax) values as AC voltages and, therefore, thicknesses were increased. Overall, these passive layers are protective of an already remarkable metal, and with greater knowledge of the properties of colored protective layers, their potential may be employed in a wide range of applications.

Existence of Resistive Switching Memory and Negative Differential Resistance State in Self-Colored MoS2/ZnO Heterojunction Devices

“…Self-colored films can be grown on many metal substrates such as titanium, steel, niobium, tantalum, and zirconium. 5 Recently, there have been many methods used in coloring various metals such as electrochemical techniques 6,7 and magnetic sputtering methods, 8,9 etc. However, the magnetron sputtering technique is a dominant method of syntheses of thin films which is extensively used at laboratory or industrial scales for the preparation of various types of single or multioxides or other oxide-based composite layers.…”

Doping of anodic nanotubular TiO2 electrodes with MnO2 for use as catalysts in water oxidation

“…The anodization of metals has long been studied in order to improve the metal's surface properties, such as corrosion and abrasion, or to decorate a metal's surface with various colors [1][2][3][4][5]. In the past 10 years, the anodization of Ti has attracted much attention as a protocol to homogenously produce 1 D semiconductive nano-objects for catalysis and photocatalysis, nanodevices, active components in energy storage or generation systems, smart membranes, and other purposes [6][7][8][9].…”