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Influence of the anode material on the breakdown behavior in dry electrical eischarge machining
(2012)Procedia CIRP ~ Fifth CIRP Conference on High Performance Cutting 2012In the last years dry electrical discharge machining (DEDM) has been proposed as an alternative to the traditional EDM. The main reason for these efforts is the absence of a liquid dielectric which results in a simpler and environmentally friendly machine. This paper presents measurements of the material removal rate in function of different tool electrode and work piece material put in relation with the breakdown behavior of the process ...Conference Paper -
Chip root analysis after machining carbon fiber reinforced plastics (CFRP) at different fiber orientations
(2014)Procedia CIRP ~ 6th CIRP International Conference on High Performance Cutting, HPC2014Machining carbon fiber reinforced plastics (CFRP) is currently being heavily investigated. The main drivers come from the aviation and automotive industry. Current drilling and milling tool geometries exhibit immense wear resulting in the damage of the work piece. Detailed understanding of chip formation mechanisms when machining CFRP is paramount and enables the optimization of tool geometries in terms of tool lifetime and work piece ...Conference Paper -
Applying Wire Electrical Discharge Dressing (WEDD) to Improve Grinding Performance of Metal Bounded Diamond Wheels
(2012)Procedia CIRP ~ Fifth CIRP Conference on High Performance Cutting 2012In order to improve grinding performance of metal-bonded diamond wheels, a proper conditioning method has to be used. In this work, wire electrical discharge dressing (WEDD) is evaluated. With a self-designed WEDD-device the dressing process can be carried out inside a grinding machine, reducing non-productive time. Moreover, the in-process WED-dressing was assessed, showing potential for future applications. Dressing experiments indicated ...Conference Paper -
Influence of Workpiece Circumferential Speed in Wire Electrical Discharge Machining
(2013)Procedia CIRP ~ Proceedings of the Seventeenth CIRP Conference on Electro Physical and Chemical Machining (ISEM)In Wire Electrical Discharge Machining (WEDM) a specific wire run-off speed is applied to compensate wear and avoid wire breakage. Since the workpiece generally stays stationary and short discharge durations are applied, the relative displacement between wire and workpiece during one single discharge is very small. In Wire Electrical Discharge Dressing (WEDD), however, the workpiece rotates at very high circumferential speeds, since ...Conference Paper -
Die-sink EDM in meso-micro machining
(2012)Procedia CIRP ~ Fifth CIRP Conference on High Performance Cutting 2012Micro EDM has been identified since more than a decade as suitable process for machining complex shaped structures with high aspect ratio, though only through variations of EDM such as micro EDM milling, micro EDM drilling, coated electrodes etc. In the current paper, we present the research focused on analysing the capability for implementation of die-sink EDM in meso - micro scale machining (structures with surface area smaller than ...Conference Paper -
Tool Life Time Extension with Nano-crystalline Diamond Coatings for Drilling Carbon-fibre Reinforced Plastics (CFRP)
(2014)Procedia CIRP ~ New Production Technologies in Aerospace Industry - 5th Machining Innovations Conference (MIC 2014)Carbon fibre reinforced plastics (CFRP) are delicate to machine as the material is highly abrasive and tends to show multiple workpiece damages like delamination, fibre pull out, uncut fibres and burnt matrix material. In result machining CFRP requires on the one hand tools which can withstand the massive wear, on the other hand geometrical highly adaptable tools to produce flawless workpieces. Diamond coated solid carbide tools can provide ...Conference Paper -
Effective Dynamometer for Measuring High Dynamic Process Force Signals in Micro Machining Operations
(2012)Procedia CIRP ~ Fifth CIRP Conference on High Performance Cutting 2012The authors present an innovative piezoelectric dynamometer (MicroDyn) providing the base for measuring high frequency signals in micro machining operations. Cutting tools with one or more cutting edges used in micro machining processes are mostly running with rotational speeds of more than 100’000 rpm, resulting in high excitation frequency. Thus, the interference of the excitation frequency of those processes with the natural frequency ...Conference Paper -
Modeling Errors influencing Active Structural Methods for Chatter Mitigation in Milling Process
(2014)Procedia CIRP ~ 6th CIRP International Conference on High Performance Cutting, HPC2014A concept of active structural method dedicated to the mitigation of regenerative chatter in milling process is presented. This concept proposes an adaptronic high performance motor spindle integrating piezoelectric actuators and accelerometers combined with an optimal control strategy whose objective is to increase the productivity in chatter-free machining conditions. The control strategy, named stabilization, explicitly considers the ...Conference Paper -
Analysis of Material Weakening in CFRP after a Drilling Operation
(2014)Procedia CIRP ~ New Production Technologies in Aerospace Industry - 5th Machining Innovations Conference (MIC 2014)Drilling Carbon Fibre Reinforced Plastics (CFRP) induces different material defects like delamination, burnt matrix material, rough bore channel surfaces, fibre pull-out and uncut fibres. Intensive research has been conducted to analyse the amount of defects caused, describing the surface and subsurface defects introduced by machining operations [1], [2]. Additionally, the mechanical strength of rivet joints has been analysed intensively ...Conference Paper -
Modeling and simulation of electrical discharge machining
(2012)Procedia CIRP ~ 1st CIRP Global Web Conference: Interdisciplinary Research in Production Engineering (CIRPE 2012)Electrical discharge machining involves complex physical processes occurring simultaneously, which lead to the removal of material from both electrodes. During the discharge, material melts, evaporates and is ejected when the plasma channel collapses. Modeling the erosion process can help to better interpret and predict results, which are otherwise difficult to understand. In this work, the material removal rate is predicted based on the ...Conference Paper