Extension of vibratory drilling technic in difficult to machine materials and the field of cutting
Today, conventional drilling methods reached their limitations in deep drilling. To counter these limitations, we developed a new technology: vibratory drilling. Vibratory drilling is a new technique that allows a good chip fragmentation with which it is possible to improve the production rate of deep drilling operations. The results obtained in steel material show the relevance of this new technology. However, while using this technology with dry conditions in aluminum, we have observed problems during cheap evacuation because of friction phenomenon. It is necessary to find a strategy in order to identify the compatible toll(s) and coating(s) with dry machining. This thesis work has focused on a study at the tribological level on the tool-chip interface. To study the impact of the geometry of the tool, a virtual study of the behavior of the head self-sustained vibration drilling was conducted by using a simulator that is also able to take into account the defections related to the drill geometry. Several experiments have shown that the use of the adapted geometry and coating can increase the tool life and production rate. In addition, we have proposed a vibratory drilling head which is compatible with all cutting machines. This head has been validated for different materials such as steel and inox.
PhD student: Olcay Onder Université de Grenoble, 17th October 2011 Directors: Henris Paris, Joël Rech (ENISE)