Improving through-plane thermal conductivity of PDMS-based composites using highly oriented carbon fibers bridged by Al2O3 particles
Improving through-plane thermal conductivity of PDMS-based composites using highly oriented carbon fibers bridged by Al2O3 particles
复制标题
使用 Al2O3 颗粒桥接的高取向碳纤维提高基于 PDMS 的复合材料的平面导热率
DOI：
10.1016/j.compscitech.2022.109717
复制
发表时间：
2022-09-13
影响因子：
9.1
通讯作者：
Zhang, Xue-ao
中科院分区：
文献类型：
--
作者：
Huang, Ruoyu;Ding, Dongliang;Zhang, Xue-ao
高功率密度电子产品的散热迫切需要高效的热界面材料。在本研究中，利用流动场的方法制备了以Al_2O_3颗粒为桥联碳纤维(CFs)空间取向的乙烯基聚二甲基硅氧烷(PDMS)复合材料。当CFS质量分数为24%，Al_2O_3质量分数为47%时，复合材料的平面导热系数(TPTC)达到38.0Wm(-1)K~(-1)。Al_2O_3桥联的定向碳纤维是一种有效的穿面导热网络。通过稳态有限元模拟，结合计算机层析成像和机器学习，定量讨论了CFS的形状因子(b/a)、空间角(Gamma)和Cf载荷(V-f)对TPTC的影响。增加的V-f对TPTC的正贡献与b/a和γ的负贡献是竞争的，两者都随着V-f的增加而增加。此外，b/a比伽马的负效应更大。该复合材料具有良好的热稳定性(T-d=407.5℃，热膨胀系数=-55.3x10(-6)K-1)、较低的压缩模数(1.71 Mpa)和硬度(47(肖尔C))，具有潜在的应用前景。这项工作为大规模制备TIMs提供了一种可行的方法，并通过引入影响因素(b/a和γ)更新了TIMs的导热机理。
Efficient thermal interface materials (TIMs) are urgently needed for heat dissipation of high-power density electronics. In this study, vinyl polydimethylsiloxane (PDMS) composites with the spatial alignment of carbon fibers (CFs) bridged by Al2O3 particles were fabricated by the flow field. The through-plane thermal conductivity (TPTC) of the composites with 24 vol% CFs and 47 vol% Al2O3 loading reached 38.0 W m(-1) K-1. The oriented CFs bridged by Al2O3 acted as the efficient through-plane thermal conductive network. Furthermore, the effects of shape factor (b/a), spatial angle (gamma) of CFs, and CF loading (V-f) on the TPTC were quantitatively discussed by steady-state finite element simulation combined with micro-computed tomography and machine learning. The positive contribution of the increased V-f to TPTC was in competition with the negative contribution of b/a and gamma, both of which increased with the increase of V-f. Moreover, b/a exerted more negative effects than gamma. The PDMS composites demonstrated excellent thermal stability (T-d = 407.5 degrees C, CTE = -55.3 x 10(-6) K-1), low compress modulus (1.71 MPa), and hardness (47 (Shore C)), which made them potential candidates for TIMs. This work offers a feasible method to prepare TIMs on large scale and refreshes the thermal conduction mechanism of TIMs by introducing the influencing factors (b/a and gamma).