Construction of 3D interconnected diamond networks in Al-matrix composite for high-efficiency thermal management

Realizing high-efficiency thermal management is of great significance for the fast growth of high-performance electronic devices. Herein, three-dimensional (3D) diamond networks (DN) are proposed as highly thermal conductive reinforcements for Al-matrix composite by template-directed chemical vapor deposition (CVD) on Cr-modified Cu foams. The diamond networks with dense and uniform structure were further incorporated with pure Al by gas pressure infiltration (GPI). Results showed that the diamond skeletons were uniformly and integrally distributed in the dense Al matrix with a compact interfacial bonding and limited interface product after GPI process. A relatively high thermal conductivity of 315.7 W/mK was achieved at a low diamond loading of 4.6 vol.%, which was equivalent to 54% enhancement compared to pure Al. The synthesized diamond networks with high quality and continuous structure can act as high-efficiency heat transfer pathways to ensure most of heat being transferred through the 3D diamond skeletons, which effectively reduced the phonon-boundary scatterings. As a consequence, the fabricated composite shows a great superiority in both thermal conductivity and thermal conductivity enhancement efficiency as compared with the conventional Al-matrix composites reinforced with even higher volume fraction of diamond particles. The construction of 3D interconnected diamond networks in metal-matrix composites might open new doors for the design and preparation of high-efficiency thermal management materials.