Metallurgical Abstracts on Light Metals and Alloys vol.54

Effect of Anisotropic Thermal Conductivity of Graphite Flakes and Interfacial Thermal Resistance on the Effective Thermal Conductivity of Graphite Flakes/ Aluminum Composite

Yan Zhao*, Kenjiro Sugio*, Yongbum Choi*, Sasaki Gen*, Zhefeng Xu** and Jinku Yu**

*Graduate School of Engineering, Hiroshima University
**State Key Laboratory of Metastable Materials Science and Technology, Yanshan University

[Published in Materials Transactions, Vol. 62 (2021), pp. 98–104]

https://doi.org/10.2320/matertrans.MT-M2020071
E-mail: ksugio[at]hiroshima-u.ac.jp
Key Words：graphite flakes/aluminum composites, orientation, interfacial thermal resistance, effective thermal conductivity, image-based simulation

The effective thermal conductivity (ETC) of graphite flake (GF)/Al composites is significantly influenced by the anisotropic thermal conductivity of GFs and the interfacial thermal resistance between both components. A two-dimensional (2D) image-based simulation was used in this study to investigate the effect of both the orientation of GFs and interfacial thermal resistance on the ETC of the composite. 10 vol% GF/Al and 20 vol% GF/Al composites were fabricated via spark plasma sintering. The microstructure ETC, and the relative density of the GF/Al composites were determined. The experimental ETCs were smaller than calculated ETCs using the rule of mixture. Additionally, the calculated ETC exhibited a decrease of 9.9% due to the effect of GF anisotropic thermal conductivity, and the ETC values decreased by 14.2% due to the effect of the interfacial thermal resistance at the Al-GF interface of the samples, which was determined to be in the range of 5.62-6.41×10^-8 m² KW^-1.

Thermal conductivities (TCs) of graphite flakes (GFs) in Sample1-2. Regions denoted as P1, P2, and P3 correspond to the microstructures. Colors means the TCs of GFs, where red is high TC and blue is low TC.