Machining of Ti–6Al–4V using diffusion annealed zinc-coated brass wire in WEDHT

Titanium is predominantly used in the industrial sectors such as bio-medical, chemical, aircraft and marine because of its improved properties such as corrosion resistance and strength. Other properties such as increased toughness, hardness, poor thermal diffusivity make the material to fall under the category of difficult-to-cut, and this gave rise to the introduction of advanced machining processes. Wire electrical discharge hybrid turning (WEDHT) is one such process which could machine electrically conductive material and is discussed in this present research work. WEDHT of Ti–6Al–4V alloy is performed with diffusion annealed zinc-coated wires in the presence of deionised water as the dielectrics. The objective of the present work is to analyse the quality of the machined surface and the amount of material removed during hybrid turning process. The input parameters chosen for the present experimentation are wire feed rate (3, 4, 5 m/min), pulse ON time (108, 111, 114 µs), servo feed (5, 7, 9 mm/min), to conduct 27 experiments. The surface quality of the machined component is studied and analysed using 2D and 3D surface profilers along with scanning electron microscopic images. The effect of heat on the machined sample and its effect on the work material surface are studied with the help of micro-hardness analysis. The amount of material removed is calculated by measuring the weight of the sample prior to and after machining. From experimentation, the lower surface roughness of 2.0087 µm is obtained at 108 µs of pulse ON time, 5 m/min of wire feed rate and 5 mm/min of servo feed. The increased material removal 0.0169 g/min is obtained at 114 µs of pulse ON time, 5 m/min of wire feed rate and 5 mm/min of servo feed. On comparison, diffusion annealed zinc-coated brass wires outperformed uncoated brass wires with 18.95% and 44.37% for surface roughness and material removal rate criteria, respectively.