Primary Research on Jet ECM Processing of Difficult to Cut Materials

Abstract

Unconventional production techniques became interesting and promising part of manufacturing methods. They provide complementary, to traditional loss methods, solutions enabling use of high - performance engineering materials for construction of machinery and industrial equipment. By using properly selected methods or their hybrids difficult to cut materials as steel, alloys, sintered materials and composites can be processed. Among the wide variety of unconventional methods of materials forming, particular attention should be given to electrochemical machining, which has been successfully used in various industries. This fact proves attractiveness and versatility of ECM. The method could be used on large scale and many variations was developed as each application requires an individual approach and has own requirements. One of the least known and described type of electrochemical machining is jet ECM where the electrolyte jet stream acts as a tool. In this kind of machining, the part is shaped only in the area where the electrolyte jet strikes the surface. This is due to the fact that the current density distribution is located just below the stream. In the area around the jet hitting the work piece thin electrolyte layer is formed. Thickness of that layer is growing rapidly. Since the electrolyte jet machining is an electrochemical process, the machined surface has all the benefits of ECM. There is no burrs and low temperature of the process prevents appearance of cracks and there is no heat-affected zone. Electrolyte jet machining can be used as well as in macro and micro drilling, turning, texturing, and electroplating. The process can be controlled by proper selection of such parameters as time, the current density and the diameter of the jet. Jet ECM can be used not only for material removal, but also for coloration (passivation) by means of anodic dissolution. 3D shaping of elements is also possible by controlling the current and the velocity of the electrolyte stream. In addition, by changing the polarity of the applied voltage it is possible to use this method in broadly considered electroplating. The paper presents results of the initial research on jet electrochemical machining (jet ECM) of acid proof steel and tungsten carbide. The material processing was carried in two ways – drilling holes and shaping grooves. Shaping was realized in milling and face turning regime. The influence of the two basic process parameters voltage and pressure was examined. In order to get rough information about the jet ECM process experiment planning method was applied. Obtained results enable planning of the further extended research.