Thermal properties of aluminum–graphite composites by powder metallurgy

• Published in: Composites. Part B, Engineering Vol. 44; no. 1; pp. 698 - 703
• Main Authors: Chen, J.K., Huang, I.S.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.01.2013; Elsevier
• Subjects: A. Metal–matrix composites (MMCs); aluminum; Applied sciences; B. Anisotropy; B. Thermal properties; Composites; E. Sintering; Exact sciences and technology; Forms of application and semi-finished materials; graphene; Laminates; metallurgy; Physicochemistry of polymers; Polymer industry, paints, wood; Technology of polymers; thermal conductivity; thermal expansion; B. Thermal properties; A. Metal–matrix composites (MMCs); E. Sintering; B. Anisotropy; Hot process; Metal matrix composite; Polymer; Composite material; Thermal properties; Hot pressing; Sintering; Graphite; A. Metal-matrix composites (MMCs); Thermal expansion coefficient; Thermal conductivity
• ISSN: 1359-8368; 1879-1069
• DOI: 10.1016/j.compositesb.2012.01.083

10–90vol.% of flake graphite is combined with aluminum powders to form aluminum–graphite composites via vacuum hot pressing process. The results show that the relative density of powder composites achieves up to 99% for composites containing 10–90vol.% graphite. With the increase of flake graphite from 10 to 90vol.% in the composites, thermal conductivity increase from 324 to 783W/mK; the coefficients of thermal expansion (CTE) in direction parallel to basal planes of graphite flakes decrease from 16.9 to −2.5ppm/K, and the CTE perpendicular to basal plane decreases from 15.2 to 10.1ppm/K. The parallel arrangements of graphite flakes and aluminum lead the thermal conductivity values of composites to agree well with parallel model estimations. The CTE of composites in a-axis agree with rule of mixture estimation representing proportional contribution of the two phases. Along the c-axis of graphite in composites, the CTE are consistent with Turner model estimations indicating that the graphite flake could absorb the expansion from the aluminum phase.