New insights into the surface features of SKD61 steel at heat-treated and non-heat-treated states as processed by powder-mixed EDM

In this paper, the two states of SKD61 steel include heat-treated (HT) and non-heat-treated (NHT), were processed by powder-mixed electrical discharge machining (PMEDM) using tungsten compound powder. Several machined surface properties were investigated by methods such as scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), 3D Laser Scanning Microscope, and X-ray diffraction (XRD). In both states, their surfaces were changed in chemical composition and content of elements (CCCE), and tungsten carbide phase (W2C) was created. In comparison with the HT state, some surface features of NHT specimens, such as: the percentage of micro-crack acreage per surface (PCAS) is better improved, the penetration of the W element into surfaces and the intensity of the tungsten carbide phase are larger, the distribution of C and W elements on the surface is a more even, and the surface topography has more uniformity and flatness. © 2023 Elsevier B.V.