Spark Plasma Sintering and Characterization of Graphene Platelet/Ceramic Composites

Abstract This paper reports a study on sintering and characterization of graphene platelet (GPL)‐reinforced ceramic composites. Alumina (Al₂O₃) and zirconia (ZrO₂) toughened Al₂O₃ (ZTA) composites reinforced with GPLs are fabricated, respectively, using spark plasma sintering. The microstructures and mechanical properties of the sintered samples are investigated. It is found that the addition of GPLs hinders the growth of the ceramic matrix grains and help form homogenous microstructures of the ceramic matrices. Agglomeration of GPLs occurs during the fabrication process and formation of GPL aggregates is impeded when ceramic powders of smaller particle size and a shorter milling process are used. Fracture toughness of the ceramic matrices is significantly improved by introducing GPLs. Approximately, a 26.4% and a 29% improvements in fracture toughness are achieved for GPL/Al₂O₃ and GPL/ZTA composites, respectively. The main toughening mechanisms induced by GPLs are pull‐out and crack bridging.