Análise da topografia da superfície usinada por descargas elétricas do aço-rápido ABNT M2

Analysis of surface topography in electrical discharge machining of ABNT M2 high speed steel. The electrical discharge machining is an exceptional procedure for machining complex shapes into electric conductor materials, mainly for those of high hardness, difficult of machining by traditional processes. At each discharge, a crater is formed in the material and a small crater is formed in the electrode. From every molten material produced in each discharge, only 15%, or less is removed through the dielectric liquid. The remaining of molten material solidifies forming a wrinkled surface. The characteristics of the obtained surface, as overlap of craters, globules of sullage, "chimneys", bubbles (formed when trapped gases are released through the resolidified material), are revealed through an analysis by scanning electron microscopy. The proposed study aimed to examine the effect of several dielectric fluids, on the surface topography and material removal rate, in workpiece of high speed steel (ABNT M2), during the electrical discharge machining.