Surface structuring by remelting with laser radiation is a new approach to shape metallic surfaces (“WaveShape”). In this structuring process, surface material is reallocated in its molten state instead of being removed, because the process is based on the new active principle of remelting. The surface structure and the microroughness result from a laser-controlled melt pool due to surface tension. Basic research has been conducted with promising results, especially for the hot work steel 1.2343. Since remelting is a thermally driven process, significant differences between metallic materials were expected due to their thermophysical properties such as thermal conductivity, absorption coefficient, viscosity, heat capacity, etc. Therefore, the presented research soughed to expand the spectrum of processable materials. Within the framework of our investigation, we compared the achieved structure height as well as melt pool dimensions for six different materials. Furthermore, we successfully tested new structuring strategies such as not linearly shaped scanning vectors to create innovative surface structures on all materials investigated. The biggest structures were achieved on the titanium alloy Ti6Al4V and the nickel based super alloy IN718. Finally, an approach of reverse structuring was investigated in order to erase existing structures and achieve a smoothed rewriteable metallic surface. The results show that surface structuring by laser remelting is well suited to process a wide range of different metals and to achieve a broad variety of different structures as well as to effectively erase existing surface structures such as milling marks.

A new approach to the reduction of the waviness of metal surfaces is based on laser remelting with modulated laser power. Waviness reduction is reached due to the modification of direction of solidification of a molten pool. The changes of the molten pool are induced by laser radiation in which amplitude is modulated in accordance with initial topography of surface. The laser process with modulated laser power allows decreasing the waviness up to 80%–95% depending of the wavelength of the initial structure. Results are given for milled steel 1.2343. This new approach shows better results in comparison with laser polishing with nonmodulated laser power.

Improving the quality of coatings made by vacuum ion-plasma technology without material removal is often a difficult task. This article provides description of the implementation of laser polishing for reduction of the roughness of such coatings. Microhardness of coating and its adhsive and cohesive properties before and after laser polishing are also mentioned.

Laser structuring by remelting (WaveShape) is a manufacturing process for metal surfaces in which structures are generated without material removal. The structuring principle is based on the controlled motion of the three-phase line in the area of the solidification front. The contour of the solidification front is imprinted into the remelting track during the continuous solidification process. Typically, harmonic surface structures in the form of sinusoidal oscillations are generated by means of WaveShape with virtually no material loss. However, a significant shape deviation is often observed over a wide range of process parameters. In this study, it was found that much of the shape deviation is concentrated at a spatial wavelength equal to half the spatial wavelength used for structuring. Therefore, an approach to reduce the shape deviations was specifically investigated by superimposing a compensation signal on the harmonic structuring signal. In this approach, a compensation signal with half the spatial wavelength was varied in phase and amplitude and superimposed on the structuring signal. Amplitude and phase shift of the compensation signal were further investigated for selected laser beam diameters and spatial wavelengths. This demonstrated that a shape deviation of harmonic surface structures on titanium alloy Ti6Al4V could be reduced by up to 91% by means of an adapted compensation signal.