摘要:The paper deals with researches of microtopography obtained at different working modes at ultrasonically aided micro-electrical discharge machining (μEDM+US) and pure micro-EDM, using both commanded and relaxation pulses. Images of machined surface taken with scanning electron microscope were analyzed in correlation with chemical composition of samples detected by X rays spectrometer. This led to some explanations of material removal mechanism, aiming at improvement of process modelling and performances increase of μEDM+US.