Foreign Experience in Electric Spark Machining

Currently, there are actively developing various additive technologies for printing metal products. Among a fairly large number of technologies, layer-by-layer laser melting of metal powder can be distinguished. Foreign scientists claim that the parts manufactured using this technology have several disadvantages: high surface roughness, high undulation, low durability. Foreign researchers propose to eliminate the shortcomings by the combined use of electric spark processing and surface plastic deformation. (Research purpose) The research purpose is analyzing the available scientific work and evaluating the possibility of using electric spark processing to reduce the roughness of the surfaces of parts obtained by selective laser melting.(Materials and methods) The paper cited the work of foreign colleagues who conducted research using a selective laser sintering unit. Electric spark treatment was carried out with an electrode made of a nickel superalloy with a diameter of 3.2 millimeters. (Results and discussion) The use of electric spark treatment in combination with surface plastic deformation on samples obtained by selective laser melting of nickel powder makes it possible to reduce their roughness by 82 percent. At the same time, the undulation parameter is reduced by 45 percent. It has been shown that electric spark treatment with a nickel alloy electrode in combination with surface plastic deformation makes it possible to obtain wear-resistant coatings with a roughness of 2.4 micrometers, a waviness of 4.9 and a thickness of 10-85 micrometers on samples made by selective laser melting. (Conclusions) The use of electric spark processing and surface plastic deformation can significantly reduce the roughness and undulation of the working surfaces of parts obtained by selective laser sintering.