Process parameter optimization in wire EDM of titanium alloy by Taguchi L16 orthogonal array approach

Titanium alloy TC4 was machined using wire EDM. A robust Taguchi design was created to produce a smooth machined surface.In the design of the experiment, the four main process parameters (pulse on time, pulse off time, wire tension, and wire feed) of wire EDM were chosen as the factors and the arithmetic mean roughness (Ra) was chosen as the response.The roughness of the machined surface was captured using a contact-type profilometer.Based on the signal-to-noise (S/N) ratio value, an optimal combination of process parameters was selected to obtain a machined surface with the lowest arithmetic average roughness.The ANOVA results showed that thepulse on time (Ton) was the statistically most significant factor in producing a smooth surface.The microstructure of the machined surface observed by the optical microscope displayed some cracks and deformed grains on the edges of the workpiece