Efficient chip formation manipulation using highly focused laser radiation

• Applicants: Professor Dr.-Ing. Dirk Biermann; Professor Dr.-Ing. Peer Woizeschke
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 566789021

Various undesirable phenomena can occur during the machining of metals. These include chip segmentation, which is usually associated with dynamic excitation of the process, especially with high-strength materials, and a missing chip breakage, especially with ductile or high-purity materials, which reduces process reliability and threatens to damage the component. Reliable chip breaking is a major challenge in the machining of lead-free and sulphur-free steels, which are taking up an increasing market share due to legal regulations. As these phenomena are based on micro-scale mechanisms, their intensity and severity can be influenced by localized manipulation. Previous methods that cause such manipulation are often based on a mechanical principle, such as chip grooves for chip breaking initiation and the so-called "constraint tool" for suppressing chip thickness fluctuations. These methods are either limited in their effective range or require elaborate peripherals in the machine. In this respect, chip breakers often only fulfill their function in a limited range of cutting parameters and the "constraint tool" must be positioned in front of the cutting edge using a highly complex device. Modern, highly energy-efficient laser beam systems that make it possible to introduce highly concentrated energy inputs (pulsed/continuous, constant/periodic/dynamic) into materials or workpieces with high temporal and spatial precision could offer a solution. The dimensions of the interaction area can be reduced down to the order of square micrometers. As a result, the laser beam tool and the process regimes of laser materials processing offer the potential to manipulate the deformation mechanisms and processes locally during the machining of metallic materials in a targeted and highly flexible manner. This project therefore plans to carry out fundamental investigations on the precise laser beam-induced manipulation of the chip formation process. On the one hand, the aim is to understand how local "manipulation spots" can be introduced into the chip during the chip formation process with the support of a highly focused laser beam as "predetermined breaking points" in a ductile material that generally has a low tendency to chip breakage, leading to a specifically controlled breakage of the chip in the subsequent bending phase. On the other hand, a high-strength material with a general tendency to chip segmentation shall be investigated to determine how the cyclic chip thickness fluctuation can be prevented by a local laser irradiation specifically adapted and synchronized to the chip formation process.

• DFG Programme: Research Grants