Kerf analysis and control in dry micro-wire electrical discharge machining

This paper describes the analysis and control method for the kerf of cut slots in dry micro-wire electrical discharge machining (μ-WEDM). First, the influence of the controllable parameters such as the air injection pressure, relative electrode feedrate, open voltage, and input capacitance were investigated based on the Taguchi methodology. The behavior of the kerf with respect to the workpiece height was also considered. Second, to improve the machining accuracy of the dry μ-WEDM, a control method was developed to compensate for the kerf based on real-time estimation of the material removal rate and by controlling the air injection pressure. In this research, all the experiments were performed in a constant-feedrate mode and with various high-pressure air injection. The experimental results show that the kerf in dry μ-WEDM was significantly affected by the air injection pressure, electrode relative feedrate, and cut height of the workpiece. Moreover, by monitoring the material removal rate of the process, the kerf in dry μ-WEDM was efficiently controlled.