Investigation of effects of cutting parameters on surface quality and hardness in the wire-EDM process

Abstract

The wire-electrical discharge machining method is one of the important modern manufacturing methods and has been widely used especially in the die manufacturing industry. The quality of the surfaces of the tools used in production, such as extrusion dies, punches, which are in contact with the produced product, is very important. The surface roughness of the extrusion die will affect the final product surface quality. In this study, pulse times, pulse pause times, wire feed speeds, and workpiece (die) thicknesses are variable, and their effect on hardness, surface roughness change, and material removal rate were researched. The study was carried out using steel material (cold work tool steel) used in products such as extrusion dies and punch. The effect of the thickness of the workpiece (die) processed by the WEDM method on the surface roughness was investigated, and, unlike the literature, the variation of the surface roughness of the wire entry side and wire exit side on the WEDMed surface was investigated. A slightly higher surface roughness was measured at the wire exit side compared to the wire entry side. In addition, the hardness of the die, which is in constant contact with the product produced, is also very important. The hardness of the die will directly affect the die life. In the study, carbon concentration changes were determined depending on the process parameters on the WEDMed surfaces, and the relationship between carbon concentration and microhardness was revealed. As a result, it was observed that the surface integrity depends on the process parameters, so the process parameters should be selected according to the desired properties of the produced parts.