Abstract:

In this study, Electrical Discharge Micro Hole Drilling process applied to specific aerospace material of Ti-6Al-4V. Although Hole-EDM drilling uses the same principles as other EDM methods, a rotated hollow electrode and pumping of dielectric coolant fluid through the electrode tube are the two distinct features. This process has alternatively used for producing fuel injectors, holes in turbine blades and Wire-EDM starter points. In this experimental study, surface observation and the effects of machining parameters of arc on-time (Ton), arc off-time (Toff) and current (I) on performance parameters were studied. Experimental works applied with single channel, cylindrical, brass, tabular electrode. Deionized water was used for coolant where was pumping inside the electrode at high pressure. The performance parameters chosen as surface roughness (Ra), material removal rate (MRR), electrode wear ratio (EWR) which occurred under the influence of the machining parameters were analysed. The purpose of analysing, Taguchi method consulted to design of experiments. Regression mathematical model was developed and analysis of variance (ANOVA) implemented to figure out of the reliability of mathematical model results. The experimental results reveal that the 500µm brass electrode has comparatively better MRR and lower EW. According to ANOVA reliable mathematical models were developed with 0,9643, 0,9827 and 0,9201 R-sq.% for Ø500µm successfully.

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