【摘要】 面对5G时代，高功率化、集成化设备器件的热管理已成为影响性能的关键因素，热管理技术的飞速发展对导热界面材料的柔软性、绝缘性、导热性及可靠性等提出了更高的需求。以二维片状石墨烯（GNP）和不同粒径的球形氧化铝（Al₂O₃）为导热填料，对其进行改性以改善填料在硅橡胶基体中的分散性，增强界面间结合，减少界面热阻。然后采用热压原位固化工艺，利用球形Al₂O₃将各向异性的GNP形成褶皱结构，制备了改性球形Al₂O₃/褶皱结构石墨烯导热硅橡胶复合材料。探讨了导热填料的含量、复合材料样品厚度等对导热硅橡胶复合材料综合性能的影响。结果表明，当复合材料样品厚度为0.8 mm,GNP质量分数为8%,Al₂O₃质量分数为50%时，复合材料面内热导率可达12.058 W/（m·K），面外热导率可达5.097 W/（m·K）。复合材料具有较好的柔性，添加GNP和Al₂O₃后，断裂伸长率均超过120%，最高可达171.68%。另外，在GNP质量分数为5%,Al₂O₃质量分数为50%时，当调节复合材料厚度为2 mm时，其击穿电压能够达到3.5 kV，满足一定的绝缘性能要求；此时面内热导率为1.979 W/（m·K），面外热导率为1.231W/（m·K）。与传统共混浇铸制备的硅橡胶片相比，该策略能够形成互联导热网络以获得高导热性能硅橡胶片，在大功率电子器件领域具有巨大的应用前景。更多还原

【Abstract】 Facing the 5G era,the thermal management of high-power and integrated equipment components has emerged as a key factor impacting performance. The rapid development of thermal management technology requires higher performances of thermal conductive interface materials including flexibility,insulativity,thermal conductivity and reliability. Taking spherical alumina（Al₂O₃） with varying particle sizes and two-dimensional graphene nanoplates（GNP） as thermal conductive fillers,they were modified to enhance their dispersion in silicone rubber matrices,strengthen interfacial bonding,and reduce interfacial thermal resistance. Then the modified spherical Al₂O₃/wrinkled GNP thermal conductive silicone rubber composite was prepared by a hot pressing in-situ curing process to form an anisotropic GNP into a wrinkled structure using spherical Al₂O₃. The effect of content of thermal conductive fillers,as well as the thickness of the composite sample on the comprehensive performances of the composite were systematically investigated. The results indicate that the composite with 8 wt% GNP content and 50 wt% Al₂O₃ content reaches an in-plane thermal conductivity of 12.058 W/（m·K） and an out-of-plane thermal conductivity of 5.097 W/（m·K） when the composite sample thickness is 0.8 mm. The thermal conductive silicone rubber composites have good flexibility,after adding GNP and Al₂O₃,the elongation at break are more than 120%,and the maximum is 171.68%. Moreover,the breakdown voltage of the composite with 8 wt% GNP content and 50 wt% Al₂O₃ content reaches 3.5 kV,satisfying the insulation requirements when the composite sample thickness is 2 mm. Meanwhile it can also reaches an in-plane thermal conductivity of 1.979 W/（m·K） and an out-of-plane thermal conductivity of 1.231 W/（m·K）. In comparison to the traditional silicone rubber sheet prepared by blending casting,this approach forms an interconnected thermal network to achieve high thermal conductive silicone rubber sheet which shows significant potential for applications in high-power electronic devices.更多还原