Experimental investigation of wire electrical discharge machining of gallium-doped germanium

This paper investigates the electrical discharge machining of gallium-doped p-type germanium with a relaxation type pulse generator. A series of experiments were performed to establish the slicing rate for different types and sizes of electrode wires. The cut samples were analyzed using a 3D optical profiler and a scanning electron microscope (SEM) for surface roughness and subsurface damage. The samples were etched and analyzed for any contamination using an X-ray energy dispersive spectrometer (EDS). This paper also investigates the use of small wire diameters (50–200 μm) to enhance slicing rate and surface characteristics. The maximum discharge energy at which germanium can be machined without any subsurface damage was determined using the experiments. The phenomenon of increase in slicing rate with decrease in wire diameter is explained using the concept of discharge energy density (Ed).