Quantitative Description of Resiudal Stress Pattern during Deep and Pendulum Grinding of 100Cr6

• Applicants: Professor Dr.-Ing. Christoph Broeckmann, since 9/2014; Professor Dr.-Ing. Fritz Klocke
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering ; Metallurgical, Thermal and Thermomechanical Treatment of Materials
• Term: from 2014 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 252869699

The objective of this joint proposal is a comprehensive study of the basic mechanisms of formation of residual stresses in transformation hardenable steels during grinding. In particular, for the first time the interactions between thermal and mechanical loads and interaction due to phase transformations during deep and pendulum grinding are fully considered. Through targeted new and further development of measurement methods for identification of thermo-mechanical loads the interaction of influencing factors shall be determined and described quantitatively in the investigated range of parameters. Furthermore, mechanical mechanisms of action (MOA) based on the knowledge of grinding forces, real contact length between workpiece and grinding wheel as well as real total kinematic contact area are in the focus of the investigations. Moreover thermal and mechanical effects are detected by enhanced measurement method. Detailed knowledge of the thermo-mechanical loads allows further investigation of the impact of mechanical MOA on phase transformation for the first time during grinding. Identification of various material properties for the hardened and tempered steel 100Cr6 is carried out in cooperation with the HASYLAB at DESY (Hamburg) and enables coupling of the total collective loads (thermal, metallurgical, mechanical) in one model. Formation mechanisms of residual stresses can thus be characterized. The detailed knowledge of the interactions between MOAs and the formation mechanisms considering the workpiece history, let the prediction of residual stress evolution in the surface layer as a function of the number of passes especially for pendulum grinding. Finally, the transferability to a complex geometry will be investigated.

• DFG Programme: Research Grants