Surface characteristics enhancement of MWCNT alumina composites using multi-pass WEDM process

Machining of ceramic composites in electrical discharge machining process is often associated with high roughness, unwanted surface and subsurface defects. This situation is generally not desired as it will reduce the life of the ceramic components fabricated in this machining process. Thus, an improvement towards enhancement of surface characteristics is desired. Multi-pass wire electrical discharge machining process can serve as an effective means of enhancing the surface characteristics in machining of ceramic composite. The current work utilizes the multi-pass concept to improve the surface properties of multi-walled carbon nanotubes filled alumina composites. A decreasing nature of surface roughness is observed with increase in the number of machining passes. A lesser appearance of unwanted debris and cracks is observed at the end of the final pass on the machined surface. The spalling effect is found to be more dominant at the initial first pass while melting and evaporation effect is more dominating in higher passes. Also, a better subsurface characteristic with lesser porous recast layer is observed with increase in the number of passes.