Coloring on metals

Since its first development, laser colouring has been considered a potential candidate to replace traditional marking and colouring required in many industrial applications due to its flexibility, with the possibility of colouring different geometries with high resolution, being environmental-friendly, no toxic chemicals or dyes are required, and being a one-step process allowing a large-scale high productivity. Laser colouring by oxidation being restricted to certain materials such as stainless steel or titanium, we have developed a novel approach to colour metallic substrates exploiting plasmonic effects, where the light interacts with nanostructures generated by ultrafast laser pulses to result in colour generation. In this work, we focus on research of laser parameters such as energy per pulse, frequency, speed, pitch, burst and pulse duration and their optimization to obtain a permanent wide spectrum of colours in different materials such as aluminium, copper or titanium. Additionally, we will present a laser platform able to showcase both colouring approaches, oxidation and plasmonic effects, allowing the generation of complex 2D and 3D designs.