Abstract Copper micro-flakes were encapsulated with in situ catalytically grown graphene and then assembled into graphene/Cu (Gr/Cu) laminated composite under pressure at high temperature. The thermal conductivity (TC) and coefficient of thermal expansion (CTE) of the composites were investigated systematically. Although in situ catalytic growth graphene can avoid structural damage in a usual mechanical alloying process and is beneficial for improving interfacial bonding, the Gr/Cu laminated composites show decreased TC in both directions compared to the pure Cu matrix prepared by the same process. The composites exhibit anisotropic thermal properties owing to their laminated architecture and two-dimensional character of graphene. Given a volume fraction of graphene, the cross-plane TC of the Gr/Cu composite is lower than the in-plane TC because of more multilayer-graphene/copper interfaces and low cross-plane TC of graphene. Although the fraction of graphene is only 0.75 vol%, the Gr/Cu composite has a significantly lower cross-plane CTE than the pure Cu matrix in a wide temperature range.

中文翻译：

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原位生长石墨烯增强铜基层压复合材料的热性能

摘要 将微铜薄片包裹在原位催化生长的石墨烯中，然后在高温高压下组装成石墨烯/铜（Gr/Cu）层状复合材料。系统地研究了复合材料的热导率（TC）和热膨胀系数（CTE）。尽管原位催化生长石墨烯可以避免通常机械合金化过程中的结构损伤，并且有利于改善界面结合，但与相同工艺制备的纯铜基体相比，Gr/Cu 层状复合材料在两个方向上都表现出降低的 TC。由于其层状结构和石墨烯的二维特性，复合材料表现出各向异性的热性能。给定体积分数的石墨烯，Gr/Cu 复合材料的横截面 TC 低于面内 TC，因为更多的多层石墨烯/铜界面和石墨烯的低横截面 TC。尽管石墨烯的比例仅为 0.75 vol%，但在较宽的温度范围内，Gr/Cu 复合材料的横截面 CTE 明显低于纯铜基体。