In this study, we mainly use cemented carbide hard alloy material for investigating a new application of wire electric discharge machining (WEDM) under air conditions. As a result, we find that cemented carbide can be machined by wire electric discharge under air conditions. From the experimental results for this material, it can be concluded that the machining rate increases when we use wire material with a high melting point and a high tensile strength at a high temperature, such as tungsten wire. It is also found that feed rate of the wire can influence the machining rate and an optimal feed rate exists. We found also that the machining rate can be increased in dry wire electric discharge machining when using a pulse waveform with a low peak current and a long pulse for the same pulse energy as compared with a high peak and a short pulse current. Moreover, owing to the shorter gap of air machining, it is possible to carry out a micromachining process, which is difficult to realize in liquid machining.
