Distortion control during grinding by computer-aided design of distortion compensation strategies

Motivation

Due to the removal of material layers with residual stresses and the induction of residual stresses by high thermal and mechanical loads during the grinding process bending potentials are generated in the surface layer. These bending potentials may lead to shape and dimensional changes. To assure the required quality, with regard to shape and dimension, especially of thin-walled workpieces, which react very sensitive on changes of the bending potential, straightening processes are needed. Using controlled straightening processes the implementation of defined compensation potentials is possible. Currently experience-based and manually carried out straightening-processes are primarily still in use in industrial practice.

Objective

The models and simulations for the prediction of shape and dimension-accuracy in grind-hardening-processes include the potential to be transferred to the conventional grinding processes. In the proposed research project controlled compensation strategies will be simulated and experimentally validated. By high thermal influences during the grinding process, reproducible and significant shape changes of thin workpieces can be achieved. Furthermore the effect of controlled thermal and mechanical straightening-processes and their compensation-potential can be understood purposefully. Using the developed simulation the combination of different straightening-processes and -strategies will be designed and finally implemented in the experimental environment.

Approach

The examination begins with the possibility of fully compensating the resulting distortion by suitable thermal and mechanical processing before and after a grinding process on profiled flat samples. First, the initial state of the samples is experimentally analyzed and described by models, which are subsequently implemented in FE simulations. Based on that, the models and simulations are modified corresponding to the grinding process with the help of experimental investigations. The effect of the mechanical and thermal process of the distortion control is initially determined with help of the simulation. The result is validated by the experimental implementation, whereby the possibility of distortion compensation by thermal or mechanical processes in the context of a pre- and post-treatment should be considered. The grinding process should be designed in such a way that a phase transformation of the material structure is avoided. From the resulting data, the investigated approaches for manufacturing compensation of component distortions are combined in order to analyze the occurring interactions and to be able to use their specific potentials in combination.