Scientific paper ID 2619 : 2024/3

Laser surface treatment technologies offer a wide range of possibilities to achieve innovative surface properties. In the course of this study, the authors analytically investigate the critical melting and boiling power densities in laser machining of various widely applied materials. With the help of the derived models, it is possible to ensure precise control for quality and cost-effectiveness in this advanced technology. After systematizing known concepts and applying the collected different material constants for copper, titanium, aluminum, St316 and ruby, models are derived and the critical power densities for the two limit states are compared. The results of the comparison show that due to the highest thermal conductivity of copper, the highest power density is d. After copper, according to the two investigated indicators, comes ruby, titanium, St316, and last in terms of d energy input is aluminum. The order of magnitude of the ratio between the boiling and melting power densities was established. This order is approximately 10 times for most materials, with the exception of aluminum, where this ratio is about 7 times. The research is related to the understanding of the basic thresholds of the material`s response to laser energy providing information in the development of new processes and applications.