SBIR Phase I: Ultra High Thermal Conductivity Aluminum/Graphite Composites from Recovered Scrap Graphite and Low Cost Natural Graphite

这个小企业创新研究（SBIR）第一阶段项目将使用回收或天然石墨开发低成本的高导热石墨/铝复合材料，用于电子热管理应用。在导电率为800 W/mK（2倍铜）时，以75%体积（v/o）随机分散在Al基体中的高导电性石墨片具有零界面电阻。界面阻抗为零是由于高v/o石墨预制件渗透过程中在界面处形成了SiC反应层。利用鳞片石墨实现尽可能高的导热性将涉及开发接近各向同性的石墨鳞片预制体结构和具有可控热膨胀的材料。所提出的工作的主要挑战将是在渗透过程中实现能接触熔融Al-Si的薄片的随机分布，以实现理想的SiC界面反应。今天的产品，从手机到复杂的成像卫星，都需要高性能的材料来跟上新兴市场的需求。消费电子和微电子封装系统更小，更热，必须在更小的空间内提供更多的功能。热管理是未来电子系统的关键技术。这项研究的一个主要目标是用轻质、低成本、高导电性的铝/石墨片复合材料取代铜和其他传统材料。

This Small Business Innovation Research (SBIR) Phase I project will use recycled or natural graphite to develop low cost graphite/aluminum composites with high thermal conductivity for electronic thermal management applications. Highly conductive graphite flakes randomly dispersed at ~75 volume percent (v/o) into Al matrix with zero interface resistance is calculated at a conductivity of 800 W/mK, (2x copper). Zero interface impedance is due to the formation of a SiC reaction layer at the interface during infiltration of high v/o graphite preforms. Achieving the highest possible thermal conductivity using flake graphite will involve developing near isotropic graphite flake preform architecture and a material with controllable thermal expansion. The primary challenge in the proposed work will be to achieve random distribution of flakes having access to molten Al-Si during infiltration to enable the desirable SiC interface reaction. Today's products, for cellular phones to sophisticated imaging satellites require high performance materials that keep pace with emerging market demands. Consumer electronics and microelectronics packaging systems are smaller, hotter and must provide increasing functionality in less space. Thermal management is critical technology for future electronics systems. A major goal of this research then is to replace copper and other legacy materials with lightweight, low-cost, highly conductive Al/graphite flake composites.