Enhanced Thermal Conductivity and Bending Strength of Graphite Flakes/aluminum Composites Via Graphite Surface Modification

Abstract

The effect of graphite surface modification on the thermal conductivity (TC) and bending strength of graphite flakes /Al composites (Gf/Al) prepared by gas pressure infiltration were investigated. Al₃Ni and Al₄C₃ phase may form at the interface in Ni-coated G _f/Al and uncoated G _f/Al composites, respectively, while the Al-Cu compound cannot be observed in Cu-coated Gf/Al composites. The Cu and Ni coatings enhance TC and the bending strength of the composites in the meantime. TC of Cu-coated G _f/Al composites reach 515 Wm⁻¹·K⁻¹ with 75 vol% G _f, which are higher than that of Ni-coated G _f/Al. Meanwhile, due to Al₃Ni at the interface, the bending strength of Ni-coated G _f/Al composites are far more than those of the uncoated and Cu-coated G _f/Al with the same content of Gf. The results indicate that metal-coated Gf can effectively improve the interfacial bonding between G _f and Al.

Keywords

graphite flakes/Al composites / metal coating / thermal conductivity / bending strength