Researchers at the Institute of Technical Physics and Materials Science at the Centre for Energy Research of the Eötvös Loránd Research Network (EK MFA) have become the first to produce a gradient-structured Si3N4 ceramic with multi-layer graphene through attritor milling and hot isostatic pressing. The development was part of the Graphene Flagship FLAG-ERA Joint Transnational Call 2017 partnership for graphene innovation developments supported by the European Commission. The partners of the consortium, led by Dr. Csaba Balázsi (EK MFA), are researchers from the Fraunhofer Institute of Ceramic Technology and Systems (Fraunhofer IKTS, Germany) and the Institute of Materials Science of the Slovak Academy of Sciences (IMR SAS, Slovakia).
The Graphene Flagship Partnering Project CERANEA develops graphene-filled ceramic sandwiches that deliver materials with enhanced properties and functionalities.
The mineralized structures of certain bones, seashells and trees have something in common: their composition varies gradually throughout their volume,providing multiple functional roles simultaneously. These are classified as functionally graded materials (FGMs) and can also artificially be engineered with tailored properties for numerous different applications, including biomedical implants, optoelectronic devices, sensors and batteries.
The use of silicon nitride as an implant is very new development in orthopedic surgery. The ceramic-graphene sandwich structure developed by the researchers is very similar to the human bone. The outer part is a Si3N4 bulk ceramic with the same mechanical properties as solid bone. With the addition of graphene, a porous Si3N4-graphene ceramic composite with open and closed porosities – similar to the bone structure – can be formed.
The porosity and conductivity of the final composite can be influenced by the amount of the graphene, something that is extremely significant, given that these properties are also useful for other industrial applications.