新型层状复合技术制备高导热石墨烯/金属叠层复合材料及其导热机理研究

How to improve the thermal conductivity of graphene/metal composites is a frontier topic in the research field of high thermal conductivity metal matrix composites. On the basis of the optimized design concept of the composite configuration for the high thermal conductivity graphene/metal composites and the outstanding properties of graphene film (GF), this proposal will adopt a new laminated composite strategy namely ‘metal-coated GF and copper foil are firstly overlapped, then entwined and finally subjected to densification to prepare the unique GF/Cu laminar composites. This strategy will hopefully enable the full exploration of the excellent in-plane thermal conductivity of graphene and realize the double-phase continuous thermal conduction channel inside the composites, so as to obtain the graphene/metal laminar composites with excellent thermal conductivity. The effect of processing parameters on the structures of GF/Cu laminar composites will be systematically studied to reveal the evolution mechanism and regulation pathway of the laminated structure. Meanwhile, based on the theory models, a multi-scale computational simulation method to describe the thermal conductivity behavior of GF/Cu laminar composites will be established to clarify the effect of GF/Cu structures on the composite thermal conductivity. The optimal design criteria for the interface/laminar configuration of high thermal conductivity GF/Cu laminar composites will be proposed. The research achievement of this proposal will provide a new design idea and theoretical basis for the development of high thermal conductivity graphene/metal composites.

如何提高石墨烯/金属复合材料的导热性能是目前高导热金属基复合材料研究领域的前沿性课题。本项目基于高导热石墨烯/金属复合材料复合构型的优化设计理念与石墨烯薄膜（GF）的优异特性，拟采用“表面镀层GF与铜箔叠放缠绕后致密化”的新型层状复合技术制备GF/Cu叠层复合材料，有望充分发挥石墨烯优异的平面热导率，实现复合材料内部的双相连续导热通道，从而获得具有高导热性能的石墨烯/金属叠层复合材料。系统研究工艺参数对GF/Cu叠层复合材料组织结构的影响，揭示层状复合结构的组织演变机理与调控途径。同时，基于理论模型，建立能够描述GF/Cu叠层复合材料热传导行为的多尺度计算模拟方法，阐明GF/Cu叠层复合材料组织结构对导热性能的影响机理，提出高导热GF/Cu叠层复合材料界面/层状构型的优化设计准则。本项目的研究成果将为高导热石墨烯/金属复合材料的制备开发提供新的设计思路和理论依据。

本项目创新提出“石墨烯薄膜（GF）与铜箔叠放缠绕后致密化”的新型层状复合工艺制备了高导热GF/Cu叠层复合材料，实现了复合材料内部的双相连续导热通道。GF/Cu复合材料的最高平面热导率可达685 W/mK，可充分满足现代高功率器件对电子封装材料的散热需求。基于热导率测试及导热模型阐明了GF结构参数—复合材料导热性能之间的构效关系，提出了高导热石墨烯/金属叠层复合材料导热性能设计的优化准则。采用“基体微合金化”法改善了石墨烯/Cu复合材料的界面结合。烧结过程中原位生成的界面碳化物纳米层/纳米颗粒不仅促进了界面结合强度和载荷传递效率，而且提升了石墨烯自身的位错强化能力，进一步揭示了界面纳米层/纳米颗粒的形成及演变机制。提出了一种改善石墨烯/Cu复合材料界面和力学性能的石墨烯缺陷工程策略，研究了等离子诱导石墨烯缺陷对石墨烯/Cu复合材料界面及力学的影响机理，揭示了等离子体诱导石墨烯缺陷的产生、演变机理及精细调控途径，阐明了石墨烯缺陷—复合材料界面—力学性能之间的构效关系。本项目研究成果丰富了石墨烯/金属复合材料的制备技术和导热/力学性能中的变化机理，对指导高导热高强石墨烯/金属复合材料的开发设计提供了新的实验依据和理论基础。