▎ 摘　　要

Alumina (Al2O3) has gained attention as an attractive structural ceramic material because of exceptional oxidation resistant, wear resistant and high strength under environment of high temperature. In this paper, a high-density (Up to 95%) graphene nanoplatelet (GNPs)/Al2O3 ceramic composite instead of non-conductive monolithic Al2O3 was fabricated by the spark plasma sintering method. Material properties such asrelative density, hardness and electrical conductivity of the composite with varying GNP contents (5, 10, 15, and 20 Volume Fractions) in Al2O3 were evaluated. We clearly observed fine grain size, reduced hardness, and high electrical conductivity in the composite having a GNP content of GNPs 15 vol.%. Thereafter, a micro electro discharge machining (mu-EDM) milling process was continuously performed on the GNP/Al2O3 ceramic composites for analyzing their surface roughness and surface topographyat different discharge energies. A high discharge energy lead poor surface properties such as uneven structure and the presence of cracks and pores. An increase in the surface roughness was observed at a high discharge energy and graphene contents. This study will provide valuable means into the relationship between functional materials and EDM parameters.