An industrial application for on-line detection of instability and wire breakage in wire EDM

One of the main challenges in wire electrical discharge machining (WEDM) is avoiding wire breakage and unstable situations as both phenomena reduce process performance and can cause low quality components. This work proposes a methodology that guarantees an early detection of instability that can be used to avoid the detrimental effects associated to both unstable machining and wire breakage. The proposed methodology establishes the procedures to follow in order to understand the causes of wire breakage and instability. In order to quantify the trend to instability of a given machining situation, a set of indicators related to discharge energy, ignition delay time, and peak current has been defined. Wire breakage risk associated to each situation is evaluated comparing the evolution of those indicators with some previously defined threshold values. The results of this work will be used to develop a real-time control strategy for increasing the performance of the WEDM process.