Temperature Controlled Front Face Flow Drilling of Magnesium Alloys

Hannich, S.1, a; Biermann, D.1, b; Wittke, P.2, c; Walther, F.2, d

Institut für Spanende Fertigung, Technische Universität Dortmund, Baroper Str. 303, 44227 Dortmund
Fachgebiet Werkstoffprüftechnik (WPT), TU Dortmund

a) hannich@isf.de; b) biermann@isf.de; c) philipp.wittke@tu-dortmund.de; d) frank.walther@tu-dortmund.de


Front face flow drilling represents a new application of the conventional flow drilling process. With this new technique it is possible to form closed holes with diameters, which can exceed the local wall thickness of the profile. By using a subsequent threading operation like thread forming, it is possible to generate solid joints. In this article investigations regarding the machining of the magnesium alloy AZ91 are presented. The feasibility of the front face flow drilling application was analysed for the machining of thin profiles with different wall thicknesses. The mechanical loads in form of the feed forces as well as torques were measured during the process. Another important aspect is the quality of the generated bores. In order to quantify the quality of the bores, measurements of the circularity as well as the diameters were carried out. Besides the variation of process parameters such as peripheral speed and feed rate, a pre-heating of the tool was conducted to raise the formability of the workpiece material and to increase the process stability. The pre-heating of the tool was accomplished by using a portable induction system with an integrated temperature control. As a result of the investigations, suitable process strategies will be recommended regarding a stable front face flow drilling operation of magnesium alloys.


LightMAT 2017, Proceedings of the 2nd International Conference on Light Materials, 08.-10.11.2017, Bremen, (2017)