The rapid development of electronic devices towards higher power density and miniaturization, has made heat dissipation a critical challenge that limits their reliability and lifespan. This study presents the preparation of natural flake graphite (NFG)-based composites, synergistically modulated by intermediate-phase carbon microspheres (MCMB) and spherical graphite (SG), via micro-hot pressing 3D additive molding technology. This innovative approach addresses the limitations of traditional metal-based heat dissipation materials. The pore structure and properties of the composites were optimized by varying the contents of MCMB and spherical graphite. The results demonstrated that the composites exhibited superior overall performance when 40 wt% MCMB and 20 wt% SG were incorporated. The compressive strength significantly increased to 32.71 MPa, while the thermal conductivity in the parallel and perpendicular directions reached 351.08 W/ (m·K) and 296.16 W/(m·K), respectively, and the anisotropy ratio was reduced to 1.18. Mechanistic analysis revealed that MCMB reduced anisotropy by disrupting the orientation of the NFG lamellae, while SG optimized the pore structure and established a multistage thermal conductivity pathway. The synergistic effects of both components resulted in a unified material with high thermal conductivity, low thermal expansion, and strong mechanical properties, offering a novel solution for the thermal management of electronic devices.

Preparation and properties of NFG-based composites synergistically regulated by MCMB and SG
    Abstract
    1 Introduction
    2 Experimental materials and Preparation methods
        2.1 Preparation of composites
        2.2 Sample Preparation
        2.3 Characterization
    3 Analysis and discussion of results
        3.1 Pore structure and densification behavior
            3.1.1 MCMB improves pore structure
            3.1.2 Impregnation principle
            3.1.3 Influence of the introduction of spherical graphite on the impregnation effect
    3.2 Physical properties
        3.2.1 Effect of MCMB incorporation on compression resistance of composite materials
        3.2.2 Effect of spherical graphite incorporation on compression resistance of composites
    3.3 Analysis of thermal conductivity of composite materials
        3.3.1 Graphitization degree of composite materials
        3.3.2 Isotropy ratio and low CTE
        3.3.3 Thermal conductivity analysis
        3.3.4 Thermal conductivity prediction model of composite materials
    4 Conclusion
    References

• Mingmin Liu(School of Mechanical and Power Engineering, China Three Gorges University, Yichang 443002, China)
• Liang Gong(School of Mechanical and Power Engineering, China Three Gorges University, Yichang 443002, China)
• Hualong Zhang(School of Mechanical and Power Engineering, China Three Gorges University, Yichang 443002, China)
• Shiyu Zeng(School of Mechanical and Power Engineering, China Three Gorges University, Yichang 443002, China)
• Aodong Gao(School of Mechanical and Power Engineering, China Three Gorges University, Yichang 443002, China)
• Siwei Li(School of Mechanical and Power Engineering, China Three Gorges University, Yichang 443002, China) Corresponding author
• Shixiong Deng(School of Mechanical and Power Engineering, China Three Gorges University, Yichang 443002, China)
• Lei Xing(School of Mechanical and Power Engineering, China Three Gorges University, Yichang 443002, China)
• Yihao Chen(School of Mechanical and Power Engineering, China Three Gorges University, Yichang 443002, China)
• Haihua WU(School of Mechanical and Power Engineering, China Three Gorges University, Yichang 443002, China, Hubei Engineering Research Center for Graphite Additive Manufacturing Technology and Equipment, China Three Gorges University, Yichang 443002, China) Corresponding author
• Xicong Ye(School of Mechanical and Power Engineering, China Three Gorges University, Yichang 443002, China, Hubei Engineering Research Center for Graphite Additive Manufacturing Technology and Equipment, China Three Gorges University, Yichang 443002, China)