Ultrathin aluminum-graphite composite foil with high thermal conductivity prepared by hot-extrusion technique.

[Display omitted] • Ultrathin Al-graphite (Al-Gr) composite foil is fabricated by hot-extrusion method. • High extrusion ratio is realized by the self-lubrication effect of graphite sheets. • High through-plane thermal conductivity (TPTC, 46 W/mK) is achieved for Al-Gr foil. • Enhanced TPTC is due to the clean interface and interconnection of graphite sheets. Heat dissipation film/ foil materials with high thermal conductivity in the through-plane direction are in high demand for improving the heat dissipation in the integrated circuits (IC) with high level of integration. In this letter, ultrathin aluminum-graphite (Al-Gr) composite foil with high through-plane thermal conductivity (46 W/m·K) was fabricated using the hot-extrusion technique. Specifically, the ultrathin Al-Gr composite foil was obtained through a high extrusion ratio (∼13:1) using the Al-Gr cylinder, during which the graphite sheets act as an effective self-lubrication media. The high through-plane thermal conductivity of the ultrathin Al-Gr composite foil is attributed to the coupled effects of the clean and tight interfacial bonding state between the Al and graphite sheets as well as the interconnected graphite sheets in the through-plane direction. Ultrathin Al-Gr composite foil with high through-plane thermal conductivity is expected as a competitive candidate for enhancing the heat dissipation capacity of the IC system. [ABSTRACT FROM AUTHOR]