Micro-hole drilling by EDM and production of fine rods for the tool electrode or other purpose have become very important in industry. This thesis describes a new method, for production of very fine rods by ultrasonic-assisted chemical machining and machining characteristics of micro-hole drilling by EDM.
For theoritical approach of ultrasonic-assisted chemical machining, the process modelling is performed using the mass transfer theory in several conditions and the predicted values agree well with experimental results. For fine rods, copper wires of initial diameter of 250㎛ are used and successfully machined into a diameter of less than 30㎛ with good repeatibility.
To drill the micro-hole, kerosene and pure water is used as a dielectric. From the experiment, Water is superior to kerosene in respect to surface roughness of inlet and outlet of hole and machined surface as well as low electrode wear. However due to the electrochemical reaction of water, small pits are remained on the workpiece surface.