Thermal and Thermomechanical Properties of Carbon Materials Dispersed Aluminum Heatsink with Al-Si Alloy

Abstract

The constant increase in power and heat flux densities encountered in electronic devices fuels a rising demand for lightweight heat sink materials with suitable thermal properties. In this article, I introduce the thermal conductivity and thermal expansion coefficient (TEC) of discontinuous pitch-based carbon fiber or graphite flake reinforced aluminum (Al) matrix composites with aluminum-silicon alloy (Al-Si) alloy fabricated through hot pressing. The small amount of Al-Si alloy contributed to enhance the sintering process in order to achieve fully-dense composites. Carbon fiber provides the reducing of TEC while the conservation of thermal conductivity and weight of Al. On the other hand, graphite flake enhanced thermal conductivity Al although TEC of Al was constant despite graphite flake addition. It seems that these results were attributed to the graphite sheet bridging close to Al/Graphite flake interface. This simple process using small quantity of Al-Si alloy allows the low-cost fabrication of Al based lightweight heat sink material.