Cutting-edge preparation is a critical step in tool manufacturing, as edge radius strongly influences cutting performance, wear resistance, and process stability. In polycrystalline diamond (PCD) tools, laser sharpening offers a flexible non-contact approach, but the challenge remains to achieve reliable radius control together with acceptable surface quality and industrially relevant throughput. This study investigates edge-radius formation in PCD laser sharpening using an industrial femtosecond laser operating in the MHz-burst regime. Particular attention is given to the influence of laser processing parameters, beam incidence angle, and scanning strategy on the resulting edge geometry and surface integrity.

Different edge-radius estimation methods are compared in order to evaluate their suitability for reliable characterization of laser-sharpened cutting edges. The results show a pronounced dependence of edge radius on laser beam incidence angle, confirming the importance of quasi-tangential irradiation for controlled material removal and improved edge formation. By appropriate selection of process parameters, cutting-edge radii down to 3.5 µm were achieved and still can be improved. In addition to radius control, the study examines surface finishing behavior and throughput improvement for different incidence angles and laser processing strategies.

The obtained results demonstrate that an industrial MHz-burst femtosecond laser can provide a cost-effective solution for PCD edge sharpening with moderate-to-good radius control. The work contributes to the understanding of process property relationships in laser based tool preparation and supports the development of practical parameter windows for industrial implementation of ultrafast laser sharpening.