The analysis of the measurement information on electrical discharge machined steel surfaces

Abstract

The problem of studying the characteristics of the surface of heat-resistant steel samples after electrical discharge machining is considered as one of the most common and effective methods for manufacturing hard-to-machine parts, depending on the processing parameters. For the purposes of the study, samples were processed on an electrical discharge machine in various processing modes in accordance with a full-factorial experimental plan, which makes it possible to implement all possible combinations of processing parameters. To assess the state of the treated surface, the surface roughness of all obtained samples was measured in the longitudinal and transverse directions. The results of the analysis of the evaluation of the obtained surface roughness profi les are presented. The previously known conclusion that the average height of irregularities increases with increasing pulse current is confi rmed. It has been established that, along with this, the fractal dimension of the profi le also changes in the scale range of 20–500 μm, calculated on the basis of the “area – scale” function. A spectral analysis of microroughnesses based on the accumulated spectral power of the surface roughness profi le of steel samples was carried out, as a result of which it was shown that the main contribution to their formation is made by spatial frequencies in the range up to 0.05 μm–1. The results obtained will be useful in planning the modes of electrical discharge machining, depending on the functional purpose of the surfaces.