Effects of adding multiwalled carbon nanotube into dielectric when edming titanium alloy

Abstract

The low thermal conductivity and gummy-like characteristic of titanium based materials reduce the tool life of cutting tool significantly when machining using conventional processes. Non-contact machining like electrical discharge machining becomes one of the alternative methods to machine these titanium alloys especially when involving complex shapes and geometry. The use of powder-mixed dielectric (PMD) has been successfully applied in machining moulds and dies steel based materials but limited study has been reported on PMD-EDMing titanium alloys. In the present work, EDMing performance of Ti6Al4V using kerosene dielectric with and without adding multi-walled carbon nanotube is compared experimentally. The effects of three controlled parameters, i.e. Pulse ON Time, Interval Time and Peak Current were evaluated on the machined samples. It is found that addition of multi-walled carbon nanotubes in dielectric shows significant improvement in material removal rate (7%) and surface finish (9%) together with reduction in white layer thickness as compared to plain dielectric without powder.