WEDM performance and surface integrity of Inconel alloy IN718 with coated and uncoated wires

In this work, using zinc-coated copper wire and uncoated brass wire, WED machining performance of IN718 was evaluated with input process variables, the discharge duration, pulse interval time, and wire runoff speed. The output variables analyzed are wire feed rate, kerf width, and recast layer characteristics. The experimental results show that zinc-coated copper wire is better in general performance when compared with uncoated brass wire. With the optimization of WEDM process parameters for the zinc-coated copper wire, it obtained 35% increase in wire feed rate and a reduction of 40% in wire consumption. When WEDM at optimized conditions with uncoated brass wire, it was found that 36% gain on wire feed rate with 80% reduction of wire consumption. Electrode material (Cu and Zn) from both wires was incorporated in the IN718 recast layer and in direction to matrix material. The kerf width is dependent on the discharge energy and wire runoff speed.