Effect of shapes and compositions of spark plasma sintered ZrB -C composites on performance as EDM 2 tools

A systematic investigation on the fabrication of Zirconium diboride-Graphite composites for application as Electrical Discharge Machining tools has been carried out.
Various percentage of graphite powder (in weight) is added to Zirconium diboride
powder before Spark Plasma Sintering and the compositions, as well as the shapes of
these composites, are varied to study its effect on the Tool wear rate and Material removal
rate. The electro-discharge machining performances of these composite tools are
compared with copper electrodes and best material removal rate to tool wear rate ratio is
achieved for the Zirconium diboride-5wt% Graphite composite tools while electro-
discharge machining of AISI steel. Amongst all the shapes, the circular tools have the
highest material removal rate to tool wear rate ratio. The improved performance of the
Zirconium diboride-5wt% Graphite composite tools is due to better densifications than
the other composites.