The synthesis and characterization of graphene-encapsulated metal particles via plasma-enhanced chemical vapor deposition

Graphene-Cu composites have potential applications in various industries due to their improved properties compared to copper. The commonly used methods for synthesizing Graphene-Cu composites involve mixing graphene nanoplatelets with Cu powders using the Hummer method and its derivatives, followed by pressing and sintering processes. However, controlling the morphology of graphene nanoplatelets and achieving homogeneous distribution poses challenges in these methods. Recently, studies have been conducted on coating copper powders with graphene using various techniques. Among these studies, the Chemical Vapor Deposition (CVD) method is suitable for industrial applications. However, coating Cu powders with graphene using the CVD method faces difficulties due to the high-temperature requirement for hydrocarbon decomposition. This thesis work focuses on the development of graphene-coated copper (Graphene-Cu) powders using a low-temperature plasma-enhanced CVD (PECVD) method. Using these coated powders, Graphene-Cu composites were produced, and their mechanical and thermal properties were investigated. The structural, mechanical, and thermal properties of the fabricated Graphene-Cu composites were determined using various characterization methods, aimed at evaluating the microstructure and graphene distribution of the composites. The obtained results demonstrate the successful production of homogeneous Graphene-Cu composites using the low-temperature PECVD method. The effect of graphene presence on the microstructure of the formed composites was investigated, and structures with smaller grain sizes and reduced porosity were observed in the presence of graphene. Mechanical tests showed that the presence of graphene increased the yield strength and elastic properties of the composites. Thermal tests revealed that the graphene coating enhanced the thermal diffusivity of the composites. The obtained results were analyzed in relation to the microstructure of the composites, and the improvement mechanisms were investigated. This study contributes to the development of production methods for graphene-reinforced copper composites and enables their potential use in various applications.