Transition metal oxides as materials for additive laser marking on stainless steel

The product information plays an important role in the improvement of the manufacturing, allowing the tracking of the part through the full life cycle. Laser marking is one of the most versatile techniques for this purpose. In this paper, a modification of the powder bed selective laser melting for additive laser marking of stainless steel parts is presented. This modification is based on the use of only one transition metal oxide chemically bonded to the stainless steel substrate, without using any additional materials and cleaning substances. The resulting additive coatings, produced from initial MoO₃ and WO₃ powders, show strong adhesion, high hardness, long durability and a high optical contrast. For estimation of the chemical and structural properties, the Raman and X-Ray Diffraction (XRD) spectroscopy have been implemented. A computer model of the process of the laser melting and re-solidification has been developed as well. A comparative analysis of the properties of both (MoO₃ and WO₃) additive coatings has been performed. An attempt for a qualitative explanation of the thermo-chemical phenomena during the marking process has been undertaken.