Proceedings of the
World Congress on Micro and Nano Manufacturing (WCMNM 2022 )
19–22 September 2022, Lueven, Belgium
doi:10.3850/978-981-18-5180-3_RP47-0058
Laser Color Marking of Stainless Steel: An Experimental Study on the Effect of Process Parameters
Department of Mechanical Engineering Indian Institute of Technology Bombay, Mumbai, India
ABSTRACT
Laser Color Marking (LCM) offers several advantages over other metal coloration methods. LCM disseminates colors more precisely and of better quality without using any chemicals or inks, making it an environment-friendly process. However, the process is mainly governed by nano/micro-meter thick oxide films formed and considering the complexity of the mechanism involved, its accomplishment at the industry level can be challenging. Therefore, LCM demands a more profound understanding of the role of each parameter for better control over the process. In this pursuit, an experimental study has been conducted to generate distinctive colors over stainless steel AISI 304 samples by varying process parameters, viz. average power, pulse width, scanning speed, pulse repetition rate, and line spacing. Color-marked samples are analyzed using optical microscopy, scanning electron microscopy, electron dispersion spectroscopy, and X-ray diffraction spectroscopy to understand the variation in surface characteristics and chemical composition. It is observed that mainly iron oxides and chromium oxides play a crucial role in the colored appearance of the surface. Color space values are measured using a colorimeter to understand the quality of color generated. Relation between the process parameters of the marking process and colors formed on the surface is studied. This study shows that the average power and pulse width are significant in generating different colors on the metal surface. This work demonstrates that bright shades of different colors with better quality can be generated through an appropriate choice of laser parameters.
Keywords: Laser Color Marking, Laser Ablation, Metal Oxidation, Stainless Steel, Colorimetry.
Department of Mechanical Engineering Indian Institute of Technology Bombay, Mumbai, India
ABSTRACT
Laser Color Marking (LCM) offers several advantages over other metal coloration methods. LCM disseminates colors more precisely and of better quality without using any chemicals or inks, making it an environment-friendly process. However, the process is mainly governed by nano/micro-meter thick oxide films formed and considering the complexity of the mechanism involved, its accomplishment at the industry level can be challenging. Therefore, LCM demands a more profound understanding of the role of each parameter for better control over the process. In this pursuit, an experimental study has been conducted to generate distinctive colors over stainless steel AISI 304 samples by varying process parameters, viz. average power, pulse width, scanning speed, pulse repetition rate, and line spacing. Color-marked samples are analyzed using optical microscopy, scanning electron microscopy, electron dispersion spectroscopy, and X-ray diffraction spectroscopy to understand the variation in surface characteristics and chemical composition. It is observed that mainly iron oxides and chromium oxides play a crucial role in the colored appearance of the surface. Color space values are measured using a colorimeter to understand the quality of color generated. Relation between the process parameters of the marking process and colors formed on the surface is studied. This study shows that the average power and pulse width are significant in generating different colors on the metal surface. This work demonstrates that bright shades of different colors with better quality can be generated through an appropriate choice of laser parameters.
Keywords: Laser Color Marking, Laser Ablation, Metal Oxidation, Stainless Steel, Colorimetry.
