金刚石增强石墨膜/铝复合材料构型设计及其导热性能

Configuration design and thermal properties of diamond reinforced graphite film/aluminum composite

针对石墨膜/铝复合材料纵向导热能力不足的缺点,本文采用高导热金刚石穿透铝层,连接上下两层石墨膜,成功在石墨膜/铝复合材料内部构建了导热通道,为复合材料提供纵向导热路径,从而有效提高复合材料纵向热传导效率。为了改善金刚石与铝基的界面结合,使用物理气相沉积(PVD)技术对金刚石表面进行镀钨处理,随后采用快速热压烧结法(FHP)制备金刚石增强石墨膜/铝复合材料。研究了界面结合质量和金刚石体积分数对复合材料热导率性能的影响。研究表明:当镀钨金刚石体积分数为10vol%,复合材料面内热导率达到峰值658 W/(m·K),相较于未镀金刚石增强复合材料提升了7%。当镀钨金刚石体积分数超过10vol%时,复合材料面内热导率呈现下降趋势。对于镀钨金刚石高体积分数(30vol%)的复合材料而言,其面内热导率降低至535 W/(m·K)。然而,随着金刚石体积分数的增加,复合材料内部导热通道数量增加,纵向热导率达到最高值177 W/(m·K),相较于未镀金刚石增强复合材料提升了34%。结果表明通过在石墨膜/铝之间引入金刚石导热通道,可有效提高复合材料的纵向导热能力。

To improve the low longitudinal thermal conductivity of graphite film/aluminum composites,this study employed high-thermal diamond to penetrate the aluminum layer and establish a thermal conduction channel within the composites to effectively enhance their longitudinal thermal conductivity.To enhance the interface bonding between diamond and aluminum matrix.Tungsten coating was applied on the diamond surface using physical vapor deposition(PVD)technology.Subsequently,diamond-reinforced graphite film/aluminum composites were fabricated through fast hot pressing sintering(FHP)method.The influence of interfacial bonding and diamond volume fraction on the thermal conductivity of the composite were investigated.The results demonstrate that at a 10vol%volume fraction of W-coated diamond,the in-plane thermal conductivity reaches its peak value at 658 W/(m·K),which is 7%higher than that of an uncoated corundum reinforced composite.However,when the volume fraction of tungsten diamond plating exceeds 10vol%,the in-plane thermal conductivity shows a decreasing trend.The in-plane thermal conductivity is reduced to 535 W/(m·K)for composites with a high volume fraction of tungsten diamond coated(30vol%).Nevertheless,as the diamond volume fraction increases,more thermal conduction channels are formed within the composite leading to an increase in longitudinal thermal conductivity up to its highest value at 177 W/(m·K),which is 34%higher than that of uncoated diamond reinforced composites.The present study demonstrates that the incorporation of diamond thermal conduction channels between graphite film and aluminum effectively enhances the longitudinal thermal conductivity of composites.