Efficient and sustainable short electric arc machining based on SKD-11 material

Abstract

SKD11 has a wide range of applications in the tooling industry. However, due to its high mechanical strength and hardness, it is a difficult material to machine. To address the issues of low machining efficiency, severe tool electrode wear, and environmental pollution caused by traditional EDM, this paper proposes a more efficient and sustainable method of EDM production called short electric arc machining (SEAM). This paper discussed the mechanism of material removal by a short electric arc and then conducted experiments on SKD11 machining with various voltage parameters using a self-designed short electric arc milling machine, analysing the material removal rate (MRR), relative tool electrode wear ratio (REWR), and specific energy consumption (SEC) of the machined workpiece. The experimental results indicate that the maximum removal rate is 15,745 mm3/min, the REWR is significantly reduced to 1.4 %, and the energy consumption ratio is 76.84 KJ/cm3. Finally, the microscopic morphology and elemental composition of the workpiece and tool electrode were analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), and the variation of cross-sectional grains was analyzed by electron backscatter diffraction (EBSD).It can be concluded that the short-arc milling method discussed in this paper can provide an efficient machining method for difficult-to-machine materials.