Investigation of the microstructure, hardness and electrical conductivity properties of Fe/Graphene compacts

ABSTRACT The effects of graphene nanoplatelets added to pure Fe powders at different rates on microstructure, hardness and electrical conductivity were investigated. Prepared mixed powders were compressed at 700 MPa pressure and sintered at 1250°C. Densities of samples were measured Archimedes technique. Scanning electron microscope was used for microstructure investigations. The hardness was measured according to ASTM E384. Phase types, average crystallite size and dislocation density calculations in sintered samples were made. Electrical resistance measurements were made with the four-point probe measurement technique. Powder mixtures containing ≤5 wt-% graphene nanoplatelets were sintered into compact samples. The smallest grain size, highest dislocation density, highest hardness and electrical conductivity values were obtained in samples containing 2 wt-% of graphene nanoplatelets.