Interfacial microstructure of graphite flake reinforced aluminum matrix composites fabricated via hot pressing

Hiroki Kurita (1, 2) , Takamichi Miyazaki (3) , Akira Kawasaki (4) , Yongfeng Lu (5) , Jean-François Silvain (2)

1 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
3 Technical Division
4 Department of Materials Processing
5 Department of Electrical Engineering

The microstructure of graphite flake (GF) reinforced aluminum (Al) matrix (Al–GF) composites was observed in detail. Due to thermal mismatch between Al and GF, an inner structure of GF was damaged in proximity to the Al/GF interface, while the unique bridging of the sticky graphite sheets barely connected the Al matrix and GF. This result suggests that the GF interlaminar strength is weaker than the Al/GF interfacial strength; the GF interlaminar strength is thus the dominant determinant of the thermomechanical and mechanical properties of the Al–GF composite. Whereas the thermal conductivity of the Al–GF composite was consistent with that theoretically predicted, the outstanding thermal expansion coefficient (TEC) of the graphite was not reflected in the produced Al–GF composites. The damaged inner structure of GF in proximity to the Al/GF interface contributes to heat transfer but does not bear the load resulting from thermal stress.

Mots clés: Metal-matrix composites (MMCs); Interface/interphase; Thermal properties; Powder processing; Metal-matrix composites (MMCs)

Domaines: Matériaux

Hiroki Kurita, Takamichi Miyazaki, Akira Kawasaki, Yongfeng Lu, Jean-François Silvain. Interfacial microstructure of graphite flake reinforced aluminum matrix composites fabricated via hot pressing. Composites Part A: Applied Science and Manufacturing, 2015, 73, pp.125-131. ⟨10.1016/j.compositesa.2015.03.013⟩. ⟨hal-03133218⟩