Investigation of gas bubble formation at spark erosion in small working gaps

Gas bubble formation, especially in small working gaps, has an important influence on the spark erosion process. This paper demonstrates that the gas bubbles originate from electrical discharge in the dielectric. Investigations are carried out for two typical dielectrics: hydrocarbon (n-dodecane) and de-ionized water. From the experimental results obtained with single pulses conclusions are drawn about what happens at discharge sequences like in a micro-erosion process