Real-time monitoring of wire electro-discharge machining semiconducting composite ceramics TiC+Al2O3

The continuously growing demand for high-precision complex-shaped parts combined with limited capabilities of conventional machining methods in their production have opened up high prospects for the use of Wire Electrical Discharge Machining (WEDM). The machining of ceramic composites with WEDM is an important area of highprecision machining. However, the high electrical resistance of such composites is a big problem, due to which WEDM of poorly conducting and semi-conducting materials cannot be monitored and controlled in the same way as that of electrically conductive materials. In particular, the adaptive control of the feed rate using monitoring of electrical parameters is no longer possible after the electrical conductivity of the workpiece material decreases to the level of semiconductors. This means that the development of monitoring and control principles and instruments for WEDM of semiconductor materials is critically important. In this work, after experimentally studying the physico-mechanical nature of EDM of semiconducting materials such as ceramic composites, recommendations for selecting the control criteria based on the vibroacoustic (VA) signal were developed. VA signals of the WEDM of semiconducting composite ceramics TiC+Al2O3 were measured to develop a more reliable method of preventing short circuits and wire electrode breakage than the conventional monitoring of voltage and amperage. We show that that the developed method is more efficient in detecting short circuits than conventional monitoring scheme and can thus be used as a foundation for the development of new adaptive control schemes of WEDM of semiconductor materials.