Characteristic evaluation of Al2O3/CNTs hybrid materials for micro-electrical discharge machining

The characteristic evaluation of aluminum oxide (Al₂O₃)/carbon nanotubes (CNTs) hybrid composites for micro-electrical discharge machining (EDM) was described. Alumina matrix composites reinforced with CNTs were fabricated by a catalytic chemical vapor deposition method. Al₂O₃ composites with different CNT concentrations were synthesized. The electrical characteristic of Al₂O₃/CNTs composites was examined. These composites were machined by the EDM process according to the various EDM parameters, and the characteristics of machining were analyzed using field emission scanning electron microscope (FESEM). The electrical conductivity has a increasing tendency as the CNTs content is increased and has a critical point at 5% Al₂O₃ (volume fraction). In the machining accuracy, many tangles of CNT in Al₂O₃/CNTs composites cause violent spark. Thus, it causes the poor dimensional accuracy and circularity. The results show that conductivity of the materials and homogeneous distribution of CNTs in the matrix are important factors for micro-EDM of Al₂O₃/CNTs hybrid composites.