Hybrid graphene/alumina nanofibers for electrodonductive zirconia

摘要

Ceramic materials have become of high industrial importance in some applications as their properties outperform ones of metallic components. However, use of ceramics is limited due to the difficulties in shaping. Electrically conductive ceramics can be machined by Electro-Discharge Machining (EDM) irrespective of its hardness or strength. In this study, yttria stabilized zirconia (YTZP) conductive composite was produced by incorporation of the cost-effective graphene coated alumina nanofibers (ANFC) into the matrix. Almost fully dense YTZP/5 vol.% ANFC nanocomposite was obtained by spark plasma sintering (SPS) at 1250 °C with uniaxial pressure of 40 MPa. Scanning electron microscopy observation of the microstructures showed that ANFCs were homogeneously dispersed in the matrix. Addition of ANFC resulted in slightly decreased mechanical properties, but the electrical resistivity of the composite dropped 9 orders of magnitude compared to monolithic zirconia, exhibiting 1.4 Ω-m, satisfying the required condition for the EDM.