Modeling of the face milling process of parallely arranged workpiece compounds

• Applicant: Professor Dr.-Ing. Berend Denkena
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: from 2013 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 235699295

In the automotive and aircraft industry the mass reduction of components is one of the most effective ways to reduce fuel consumption and emissions. A lightweight strategy, which is used for highly loaded components, is the combination of two or several materials to form a workpiece compound. That way a component can be designed depending on the local load using most qualified materials. For the production of high-performance workpiece compounds (e.g. an engine block) high quality requirements concerning the accuracy of dimension and shape as well as surface quality must be fulfilled. However, significant shape deviations occur due to unequal cutting properties of the materials. A significant shape deviation is the projecting edge at the material transition which is specified by the average projecting edge of the single materials to each other. Another significant shape deviation is the transition deviation which occurs at the material joint. It arises from the loading and unloading of the cutting edge at the material transition. Furthermore different surface roughnesses occur in spite of equal kinematic engagement conditions, which differ more when machining workpiece compounds in comparison to single materials. A closer look at the cutting tool reveals changes of the cutting edge due to adhesions, built-up edges, tribochemical reactions or wear, which reduce the tool lifetime, its efficiency and might cause surface damages (e.g. scratches). The aim is to develop a model that enables the prediction of the workpiece shape during the face milling of workpiece compounds. Its input parameters are the tool geometry, process parameters, material data, statical and dynamic tool properties in the machine tool as well as experimental data of workpiece damages. For this purpose, significant influencing factors on the shape deviations of the surface are identified and characterized first. After that, individual models are developed in order to predict the projecting edge, transition deviation and surface roughness of the workpiece. These models are validated on the basis of experiments, summarized and validated in a comprehensive model, and adjusted if necessary, so that a random validation based on other workpiece compounds can be realized. This is for an estimation of the general validity.

• DFG Programme: Research Grants