Investigation of the effect of cryogenic treatment on fast drilling performance of brass electrodes

The material 1.2379 (X153CrMoV12), a cold work tool steel, is very hard and difficult to machine. In this study, experiments were analyzed by using EDM method for fast hole drilling and cryogenic treatment of electrode rods using various parameters. Brass electrode tubes with Ø 3, Ø 2 and Ø 1 diameter sizes were used in the experiments and the electrodes were deep cryogenically treated at 196 C for 12 hours, shallow cryogenically treated at -80 C for 6 hours and non-cryogenically treated electrodes were tested. In all experiments, the processing performance results were analyzed by using 7A-4A current, 30-23µs arc time (Ton), 3 µs dwell time (Toff) and 3V voltage values considering the machine safe operating parameters. . The effects of cryogenically treated and untreated electrodes on machining performance were evaluated with machining time (min), metal removal rate (g/min), electrode wear rate (g/min), kerf (degrees), microhardness changes and workpiece surface morphology analysis. According to the results, it was observed that deep cryogenic treatment partially increased the MRR (5%) at 6 hours of application and reduced the relative tool wear up to 40% when applied for 12 hours in the tests performed on 1 mm electrodes. SEM and EDS analyzes were also performed to examine the surface properties. According to SEM and EDX analysis of the drilled hole surfaces, workpiece and brass electrode residues were found on the machined surfaces. The clamping apparatus designed.