# Adjustment of Wire Vibrations in Order to Improve Geometric Accuracy and Surface Roughness at WEDM
## 1 Introduction  
Because WEDM technology is a machining technologies with a high quality of machined surfaces, even a small geometric deviation in certain parts of a workpiece from the desired shape has an essential influence on the overall functionality of the component. Many research studies in this field point to this undesirable effect, such as [PERSON] [1], [PERSON] [2], and [PERSON] [3]. In their research, they focused mainly on the identification of deviations in the eroded area from nominal dimensions. It is true that compliance with dimensional accuracy is an important, but not always, key factor in obtaining the required quality of an eroded surface. In practice, there is a large number of cases where the dimensional accuracy of a machined surface is maintained; however, the workpieces are still unsatisfactory in terms of exceeding permissible shape deviations. In the past, only a very small number of researchers have focused on research into these shape deviations. In addition, many of them have tried to understate the impact of geometric deviations of eroded surface shapes on the functionality of the finished product. They attributed this undesirable effect, in particular, to the inappropriate feed rate of the wire electrode. In particular, [PERSON] [4], [PERSON] [5], and [PERSON] [6] paid attention to this area of research. In their works, they described a certain improvement in the geometric precision of the eroded surface by reducing the feed rate of the wire electrode. However, it should beemphasized that too low a wire electrode feed rate leads to a loss of productivity in the electroerosion process. In order to achieve high reliability and a long lifespan for products, it is necessary to focus on the application of high-strength materials and on achieving high-quality machined surfaces. This was also noted by [PERSON] [7] who claimed that, in practice, we often encounter the fact that emphasis is placed only on qualitative indicators of a machined surface, concerning its dimensional accuracy, while geometric precision is treated as a sort of secondary quality parameter. In practice, its evaluation is only considered superficially. At the same time, according to [PERSON] [8], it is the geometric deviations of the machined surface that have a primary influence on the operational functionality, durability, and service life of products made using progressive WEDM technology. [PERSON] [9] addressed the influence of tool electrode vibrations on the quality of eroded surfaces in terms of geometric accuracy. He found that the tool electrode vibrations also play significant role in the occurrence of geometric inaccuracies of machined surfaces after WEDM. In his study, he tried to identify the effect of the tensioning force of the tool electrode close to critical values in order to reduce the oscillation amplitude of the wire electrode during the electroerosion process. However, over the course of his work, he did not provide precise recommendations that could lead to their complete elimination. In this context, it is useful to draw attention to the fact that, by increasing the tensioning force of a wire electrode, it is possible to significantly contribute to an improvement in several qualitative indicators of a machined surface, after WEDM, in terms of geometric precision. Nevertheless, certain limitations follow from the material properties of wire electrodes, which only allow tensioning by a certain maximum force (_Fw_). When it is exceeded, the wire electrode breaks, which again has an adverse effect on the overall productivity of WEDM. [PERSON] [10], in his research, also focused on tool electrode vibrations, and he justified his research mainly by the fact that the issue of tool electrode vibrations, during WEDM, and their impact on the quality of an eroded surface, has been given very little space in the past. Another group of researchers addressed the issue of the effect of wire electrode vibrations during WEDM on the quality of a machined surface in terms of surface roughness.