Material removal behavior during grinding of tungsten carbide cemented carbides with multiphase alternative binder materials

• Applicant: Professor Dr.-Ing. Thomas Bergs
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 538782306

Due to their high fracture toughness in combination with a high hardness, cemented carbides are used e.g. for cutting and forming tools and other wear-resistant components. Due to their material properties, cemented carbides are difficult to machine and are mostly machined by grinding. Due to social, ecological and economic reservations about cobalt (Co), binder materials other than Co or Co-reduced materials are being used more and more frequently. At present, the cutting behavior during grinding of carbides with multiphase alternative binder materials has not been sufficiently researched. The results of this research project will contribute to the improved understanding of the cause-effect relationships (CERs) between the process input, state and output variables in grinding of carbides with alternative binder materials, as well as to the knowledge-based process design of the grinding process of carbides with multiphase alternative binder materials. The aim of the present research project is to develop a model for the cutting process during grinding of cemented carbides with multiphase binder materials other than Co. On the basis of cemented carbides with WC as hard phase and varying binder materials, the influence of the phase composition on the machining behavior is to be described qualitatively and quantitatively. Based on the model of BIFANO and WIRTZ, the CERs between the process input, process state and process result variables are to be investigated and mapped in a heuristic model. For this purpose, the model of WIRTZ has to be questioned and extended with respect to the dimension of the different material phases. Consequently, the influence of the material composition on the cutting behavior and the process result in the form of edge zone damage has to be investigated. The work program is divided into five work packages (WP). In WP1, the carbides to be investigated are characterized on the basis of material and microstructure properties at the macroscopic and microscopic level. In WP2, the machining behavior and the edge zone formation are investigated with the aid of single-grain scribing investigations, which are an analogy to the grinding process. The results from AP2 are incorporated into both the qualitative explanatory model and the quantitative computational model. The qualitative explanatory model is additionally supplemented by the analysis of high-speed camera images in WP3. In WP4, the transferability of the findings obtained is to be verified by means of grinding tests. For this purpose, average chip thicknesses are specifically set via the process parameters. The results will be verified by analyzing the ground surfaces. In WP5, a qualitative explanatory model for the machining process and a quantitative calculation model of the material-specific, critical chip thickness will be developed.

• DFG Programme: Research Grants