Laser powder bed fusion (PBF-LB/M) enables the production of lightweight, customizable titanium components, but the minimum feature size is limited to several hundred micrometers.

This work demonstrates the use of ultrafast laser percussion drilling (260 fs) to overcome this limitation by fabricating precise shallow dimples and deep microholes in PBF-LB/M-generated Ti64 parts.

Dimples as small as 50 µm with laser-induced periodic surface structures (LIPSS, ~1 µm spatial period) were obtained, highlighting enhanced microstructuring capabilities. The study shows that peak fluence and pulse number are key to controlling dimple geometry, while pulse energy determines the depth progression and achievable depth of microholes. Through-holes of 1.5 mm depth and 110 µm diameter were achieved, corresponding to an aspect ratio of 13.5.

These findings demonstrate the feasibility of using ultrafast laser drilling to introduce micrometer features and high-aspect-ratio geometries, broadening the applications of PBF-LB/M components in high-precision fields.

Advanced high-speed synchrotron X-ray imaging techniques enable real-time observation of the ablation of micro-holes and -grooves in stainless steel using ultrafast lasers. The images reveal valuable insights into the underlying dynamics of the processes.

Recent findings highlight the role of heat accumulation and laser polarization in the formation of micro-holes. Two mechanisms driving the side channel formation were identified. The first involves lateral deflection of the borehole tip, while the second occurs when drilling resumes after an interruption.

During multi-scan ablation of grooves, heat accumulation causes melt fluctuations and the formation of numerous micro-holes at the groove bottom, which significantly influences the depth progress.

These observations improve the understanding of transient effects in ultrafast laser processing, enabling the development of optimized laser parameters for improved precision, fewer defects, and enhanced productivity in industrial applications.

Conventionally, metals and plastics compete due to their differing mechanical, physical, chemical, and tribological properties. However, hybrid components that synergistically utilize the advantages of both materials present significant potential for weight reduction, functional integration, and cost savings. The production of plastic/metal hybrid components can be efficiently achieved during the primary forming process of the plastic part (injection molding) using macrostructures, eliminating the need for additional joining technologies. Macro structuring on metal components is accomplished through laser or electron radiation via repeated micro-welds (Surfi-Sculpt®). The strength of these structures can be tailored by adjusting process parameters, orientation, and geometry of the micro-welds. This study presents initial results regarding individual structural strength on stainless steel samples. It demonstrates the dependency of bending strength and structure geometry on ambient pressure as well as the increase in structural strength in welding direction. Higher energy input allows for elevated macrostructures but may reduce bending strength.

In pulsed laser ablation, the interaction of successive pulses is significantly affected by the surface morphology generated by preceding pulses. This study investigates the impact of burr formation around laser ablation spots on the absorption characteristics of subsequent pulses, highlighting its critical role in determining the sidewall quality during laser percussion drilling of metals. The findings allow for new approaches in optimizing laser parameters for enhanced machining precision and surface quality.

Ultrashort pulsed (USP) lasers have been widely investigated in micromachining of various materials. The unique laser characteristics induce nonlinear material absorption mechanisms and result in excellent processing quality. However, conventional USP laser processes are typically confined to 2-2.5D due to limitations inherent to conventional laser machine concept.

We introduce an ultrashort pulsed laser robot (USPLR) system, wherein a USP laser is attached to a robot axis, beam guidance is realized by intelligent, adaptive discrete optics. The combined movement of the robot and a 2D galvanometer scanner not only enhances the processing flexibility in one plane but also extends processing capabilities to three dimensions. Here, we present and discuss comprehensive experimental results on the performance of the USPLR system and demonstrate first applications in material processing. In addition, we compare an alternative beam guiding concept for the USPLR system based on an optical fiber.