Laser-Induced Color Marking of Titanium Alloy

Abstract

Keywords: laser color marking, titanium alloy, surface oxidation, laser processing parameterCopyright © 2016 Universitas Ahmad Dahlan. All rights reserved. IntroductionColor markings on metal surfaces are made by the traditional technologies such as printing, electroplating, painting and so on. However, these processes have some limitations in practical applications [1]. The poor scratch and wear of printing coatings and complexity of electroplating processes and high cost of paintings are recognized problems. So the traditional color marking technologies are gradually replaced by the laser color marking technology which requires a laser to scan the metal surface and give rise to surface oxidation to create a permanent color marking on a metal surface and does not use any chemicals, coatings or tools [2]. The laser-induced color patterns can make the metal surface visually more attractive and are gaining interest for consumer products [3,4].A lot of investigations have been carried out to better understand the laser color marking process. The color patterns were marked on stainless steel by an infrared laser [5,6], or fiber laser [7][8][9][10][11][12] or KrF excimer laser [13] or UV laser [14] and marked on titanium by a fiber laser [15,16]. These studies mainly focused on the influence of laser processing parameters on the resulting colors and the analysis of laser induced oxide films on metal surfaces. It has been proved that the laser-induced colors are sensitive to laser processing parameters which consistently appear in these studies are laser power, scanning speed, and focal plane offset. But the controlled parameters differ in various laser marking systems. The effect of other parameters on the laser-induced colors was not reported, such as pumping current, Q-switch frequency, laser line spacing, Q release time etc. Regarding the analysis of oxide films, the surface morphology and optical properties of the oxide films and their thickness were mainly studied. But as the laser beam generates intense heat, internal stresses may occur, which may cause distortion of the substrates outside its limits. It is must be avoided in industrial applications of laser coloring marking technology. So far the related researches haven't been reported.In this study, a Nd:YAG nanosecond laser was used to mark several color square patterns of 5mm×5mm on titanium alloy substrates in air. The influence of selected laser processing parameters on the obtained colors was investigated by One-Factor-at-a-Time (OFAT) experiments. As well as the influence of the resulting colors on the substrate was

Influence of the Overlap Coefficient on the Contrast in Laser Marking of C110w Steel

“…It can be noted that these factors in most cases are interrelated and have a complex effect on the specific technological process [7]. The article [8] with a nanosecond pulsed laser analyses the influence of the pulse tracking frequency and the distance between the processing lines when scanning titanium alloy substrates on the process of colour laser marking. The authors in [9] investigated the effect of a number of parameters of laser processing, such as power and fill factor of laser pulses on a certain working area when marking barcodes on the surfaces of aluminum alloys.…”