Cutting edge preparation of ultra-hard cutting materials

• Applicant: Professor Dr. Bernd Breidenstein, since 7/2019
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: from 2016 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 277230623

The performance of cutting tools is largely determined by the cutting edge microgeometry. For the production of specific cutting edge microgeometries, mechanical processes are mostly used in industry. Regarding super hard cutting materials such as polycrystalline diamond (PCD) and polycrystalline cubic boron nitride (PCBN), these mechanical processes increasingly reach their limits with regard to productivity, occurring wear and the associated process reliability. For this reason, within the scope of the DFG project "Schneidkantenmikropräparation hochharter Schneidstoffe", laser ablation is being investigated concerning the suitability for the generation of cutting edge micro-geometries on PCBN tools. The scope of the project is to understand the changes in the properties of the cutting material induced by the laser energy input in dependence of the process parameters as well as the cutting material composition (PCBN content and binder) and to derive suitable process strategies for producing symmetrical and asymmetrical cutting edge microgeometries. It has already been proven in the course of the ongoing work that the cutting material properties (surface quality, chemical composition, hardness, residual stress) are significantly influenced by the laser process. Initial findings also show that the tool cutting performance is largely influenced by the changes in the properties of the cutting material resulting from the laser process. The aim of the proposed continuation project is the knowledge of the influence of laser processing of PCBN tools on their operational behavior. First, the mechanical stresses in the cutting wedge of rounded PCBN tools are determined by a combined approach of experiment and simulation. This serves as a basis for evaluating the impact of laser cutting edge micro-preparation on the load capacity and wear resistance of PCBN tools. In particular, mechanisms of initial tool failure (cutting edge breakouts) and continuous wear forms (flank wear, crater wear) are experimentally investigated in various applications. The aim of this research is to link the resulting wear mechanism to the cutting tool properties induced by laser machining. Finally, the performance increase of PCBN tools is demonstrated by laser preparation using optimally adjusted laser process strategies.

• DFG Programme: Research Grants
• Ehemaliger Antragsteller: Dr.-Ing. Thilo Grove, until 6/2019