Abstract
In electrical discharge machining, processing accuracy was effected by behaviors of fused material. Fused material behaviors depend on the pressure during electrical discharge. The mechanism of pressure occurrence was needed to clear. In this study, pressure was measured by optical fiber sensor during single pulse discharge. Gap region medium viscosity was changed by medium and temperature. As the results, bubble collapse was only occurred with low viscosity. In the case of low viscosity, it was found that bubble collapse time was increased as discharge current increased without viscosity.
