Synthesis by Vacuum Infiltration, Microstructure, and Thermo‐Physical Properties of Graphite–Aluminum Composite

Graphite prefabricated blocks are fabricated using natural flake graphite and pore‐forming agent of urea, and then high volume fraction graphite–aluminum (Gr–Al) composites are fabricated applying graphite prefabricated blocks and aluminum alloy (ZL101) by vacuum infiltration process for the electronic packaging materials. The microstructures of graphite prefabricated block and Gr–Al composites are observed in detail, which shows that the graphite maintains a good integrity and arranges uniformly in aluminum alloy. Besides, the result shows the formation of a tightly adhered interface between the side surfaces of the graphite and aluminum alloy matrix, and no detrimental Al₄C₃ phase is found. Thermal properties of Gr–Al composites are researched perpendicularly to the pressing direction. Thermal conductivity increases from 282 to 398 W mK⁻¹ whereas the volume fraction of flake graphite increases from 40 to 75% in the composites, this reveals that the vacuum infiltration is a very promising method to synthesize Gr–Al composites.