High-efficiency fabrication of functional structured array surface on hard metallic ceramic materials by a novel magnetic field-assisted self-assembly electrode

Hard metallic ceramic materials such as silicon carbide (SiC) and Tungsten carbide (WC), have been widely used in many important industrial applications attributing to their high hardness and stable material properties. Electrical discharge machining (EDM) is one of the effective methods to fabricate the functional structured surfaces on these materials. However, serious electrode wear together with a complicated electrode replacement process leads to high fabrication costs and low production efficiency. Hence, EDM with a self-assembly electrode was proposed for the fabrication of the functional structured array surface on metallic ceramic materials. Based on the discrete design concept, we designed a magnetic field-assisted self-assembly electrode (MASAE). The MASAE is made up of an array of ferromagnetic metallic balls attracted together under the guidance of the magnetic field generated by a permanent magnet. By adjusting the position, number, and size of the metallic balls, different MASAEs can be prepared. After the EDM process, different structured surface arrays on the metallic ceramic materials can be fabricated. The shape evolution and surface quality of the EDMed structure arrays were measured and analysed by ContourGT-X 3D optical profile and scanning electron microscope (SEM). The composition and phase changes of the EDMed surface were characterized by energydispersive X-ray spectroscopy (EDS) and Raman. Compared with the traditional integral electrodes made by milling or turning, the MASAE has a great advantage in preparation time, cost-effectiveness, and replaceability. The proposed manufacturing strategy
provides an effective way for the design and manufacturing of functional structured surfaces on metallic ceramic materials.