Fabrication of vertically aligned single-walled carbon nanotube block reinforced copper matrix composites with anisotropic thermal properties for thermal management

The controlled alignment of vertically aligned single-walled carbon nanotube (VASWCNT) blocks possessing a certain degree of geometric anisotropy and anisotropic thermophysical properties within a copper matrix enables copper matrix composites to achieve anisotropic behaviors, providing a promising strategy for the development of thermal management materials with directional performance. By employing a binder-assisted mechanical mixing approach in combination with spark plasma sintering–assisted hot pressing, a uniform dispersion of VASWCNT blocks within the copper matrix was achieved, along with a high degree of axial alignment along the horizontal direction. Furthermore, electroless copper plating on the surfaces of the VASWCNT blocks significantly improved interfacial wettability and bonding with the copper matrix, thereby facilitating more efficient thermal transport. As a result, the fabricated composites exhibit pronounced anisotropic thermal properties, simultaneously achieving high thermal conductivity (326.4 W/m·K) and a low coefficient of thermal expansion (13.2 ppm/K), demonstrating their strong potential as advanced materials for next-generation thermal management applications.