Influence of feed rate and tool rotation during micro-EDM of MWCNT alumina composite

The advancement in conducting filler reinforcement to ceramic materials has improved the overall properties of the matrix ceramic material. The enhancement can be in either thermal, electrical or mechanical properties as per... [ view full abstract ]

The advancement in conducting filler reinforcement to ceramic materials has improved the overall properties of the matrix ceramic material. The enhancement can be in either thermal, electrical or mechanical properties as per the nature of the conducting filler and desired characteristic. Similar approach is also reported in the current work. Multi walled carbon nanotubes of 12 vol. % concentration is reinforced to alumina which increases the net electrical conductivity of the composite. An improvement in the electrical property of the ceramic material allows them to be readily machined by electrical discharge machining process. A micro electrical discharge machining process is used to investigate the influence of feed rate and tool rotation to the overall machining rate. An appreciable machining characteristics is observed in all the non-parametric combinations. A better material removal characteristics is obtained with rotation of the tool.   This is brought forward by proper channelization of the dissociated sparks. However, a higher width of the drilled hole is obtained when the tool starts rotating. Also, an overall better machining rate is observed at lower speed of tool rotation as compared to higher speeds. A lower machining rate is observed with increase in the feed rate during machining of multi walled carbon nanotubes filled alumina composites, unlike that of machining metallic alloys. This is mainly due to increased tool reciprocation with increased feed rate due to lesser electrical conductivity. The machined hole is further observed to have irregular edges throughout due to high brittleness of the composite.