Characteristic evaluation of Al2O3/CNTs hybrid materials for
micro-electrical discharge machining
micro-electrical discharge machining
(1. National Core Research Center for Hybrid Materials Solution, Pusan National University,
Busan 609-735, Korea;
2. Department of Electrical Engineering, Pusan National University, Pusan 609-735, Korea)
Busan 609-735, Korea;
2. Department of Electrical Engineering, Pusan National University, Pusan 609-735, Korea)
Abstract: 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.
Key words: Al2O3/CNTs hybrid materials; micro-electrical discharge machining; micro-hole; electrical conductivity