Determination of thermo-mechanical quantities with a sensor-integrated tool for single lip deep hole drilling

Abstract

To adjust the subsurface workpiece properties, such as hardness and residual stresses as well as surface quality, machining processes are often followed by forming, peening or heat treatment processes. An appropriate setup of the machining process can adjust the desired properties. The work presented here is part of an interdisciplinary research project in the framework of the priority program "Surface Conditioning in Machining Processes" (SPP 2086) of the German Research Foundation (DFG). This research project has the main objectives to determine the actual thermo-mechanical state of the surface and subsurface in single lip deep hole drilling during the process by means of a sensor-integrated tool as well as to control the process parameters to achieve the desired workpiece properties.Preliminary test series are related to the determination of the thermo-mechanical boundary conditions with thermal, material and machining models. From the obtained results, the requirements concerning the sensor-integrated tool can be derived. Further steps include the development of a tool for the in-process determination of the real cutting conditions, the selection and integration of sensor systems as well as the correlation of process states with workpiece conditions. The single lip deep hole drilling tool will be equipped with sensor systems for the acquisition of temperatures, forces, torques and vibrations close to the affected zone. In particular, for the determination of the process temperature close to the cutting zone, a multi-sensor approach was chosen. Effects on the workpiece can then be investigated using material simulations. The elaboration of a control strategy and its implementation in a deep hole drilling machine will finalize the current project phase. The final goal is that the required workpiece surface and subsurface properties can be controlled based on measurement and simulation data.