Nazeer Faisal, Ma Zhuang, Xie Yitong, Gao Lihong, Malik Abdul, Khan Muhammad Abubaker, Wang Fuchi, Li Hezhang
School of Materials Science and Engineering, Beijing Institute of Technology Beijing 100081 China
National Key Laboratory of Science and Technology on Materials under Shock and Impact Beijing 100081 China.
RSC Adv. 2019 Jun 7;9(31):17967-17974. doi: 10.1039/c9ra03743h. eCollection 2019 Jun 4.
Recently, metals with graphene and graphene oxide have been extensively used to enhance the mechanical and anisotropic thermal properties of composites. A novel facile fabrication approach of layer by layer self-assembly followed by hot press sintering was adopted to make copper-reduced graphene oxide composites. The microstructure and heat dissipation properties of pure copper and copper-reduced graphene oxide composites were analyzed with the help of SEM and continuous laser machine analysis. Thermal diffusivity of pure copper and copper-reduced graphene oxide composites was examined in different directions to measure the anisotropic thermal properties by using different volumetric percentages of reduced graphene oxide in the composites. Extraordinarily high anisotropic thermal conductivity of the copper-reduced graphene oxide composites was obtained at a very low concentration of 0.8 vol% reduced graphene oxide, with the difference between the thermal conductivity in-plane and through-plane being a factor of 8.82. Laser test results confirmed the highly anisotropic behavior of our copper-reduced graphene oxide composite with the remarkable property of heat dissipation. The three point bending test was also performed to check the flexural strength of the composites. At 0.6 vol% rGO, the flexural strength was noted (∼127 MPa), and it is 22% higher than that of pure sintered Cu. The high value of anisotropic thermal conductivity and higher flexural strength exhibited by the copper-reduced graphene oxide composite produced using a simple two-step fabrication method give us new hope to use these materials as heat sinks in thermal packaging systems.
近年来，含有石墨烯和氧化石墨烯的金属已被广泛用于增强复合材料的机械性能和各向异性热性能。采用一种新颖的逐层自组装然后热压烧结的简便制造方法来制备铜-还原氧化石墨烯复合材料。借助扫描电子显微镜（SEM）和连续激光机分析，对纯铜和铜-还原氧化石墨烯复合材料的微观结构和散热性能进行了分析。通过在复合材料中使用不同体积百分比的还原氧化石墨烯，在不同方向上检测了纯铜和铜-还原氧化石墨烯复合材料的热扩散率，以测量其各向异性热性能。在还原氧化石墨烯浓度低至0.8体积%时，铜-还原氧化石墨烯复合材料获得了极高的各向异性热导率，其面内热导率与垂直面热导率之差为8.82倍。激光测试结果证实了我们的铜-还原氧化石墨烯复合材料具有高度各向异性行为以及卓越的散热性能。还进行了三点弯曲试验以检查复合材料的抗弯强度。在还原氧化石墨烯含量为0.6体积%时，抗弯强度为（约127兆帕），比纯烧结铜高22%。使用简单的两步制造方法制备的铜-还原氧化石墨烯复合材料所展现出的高各向异性热导率和更高的抗弯强度，为我们将这些材料用作热封装系统中的散热器带来了新的希望。
