Copper Alloy Marking by Altering its Surface Topology Using Laser Heat Treatment

The paper studies the effect of the parameters of laser heat treatment of the copper alloy surface on the formation of color palette during its marking. The prospects of using laser marking of the surface of metal products can be substantially broadened by managing the color of the applied image. The “color” version of the laser marking method can be effectively used in metallurgical industry for protecting the product from tampering. The authors have studied metallographic imaging of the metal surface of the samples treated with laser radiation under different parameters. The measurement of such structure elements of the sample surface as laser exposure zones (LEZ) and heat exposure zones (HEZ), and statistical treatment of the obtained data were performed. Based on the compiled contrasting color groups, the mean values of the measurements and standard deviations were determined. A correlation between the laser radiation parameters and copper alloy surface topology has been established. The colors of the obtained fixed image were identified by using the RAL color chart. It was found that such laser radiation parameters as laser beam travel speed and defocusing affect the color of the brass surfaces. These parameters were used to create four contrasting color groups.