Performance optimization of composition-particle size dual-gradient diamond/SiC materials by DLP printing and reactive infiltration

Conventional homogeneous materials face a trade-off between thermal conductivity and toughness, limiting their application in high-power electronics and extreme structural conditions. This study addresses this challenge by fabricating SiC-based diamond composites with dual gradients in composition and particle size using digital light processing (DLP) 3D printing and reactive melt infiltration (RMI). We systematically investigated the effects of diamond content and particle size on the rheological behavior, photocuring properties of the diamond/SiC composite slurry system, as well as the silicon infiltration performance of the samples. Optimal slurry rheology was achieved with 3 μm diamond at 20 vol% under the condition of complete silicon infiltration. Furthermore, by increasing the diamond particle size, unobstructed liquid-phase silicon infiltration can be achieved even at a diamond volume fraction of 50 %. Verified by finite element simulation and experiments, the prepared dual-gradient composite samples exhibit a thermal conductivity of 222.40 ± 7.21 W/(m·K), a flexural strength of 275.53 ± 27.08 MPa, and a flexural modulus as low as 173.92 ± 22.82 GPa.This approach provides significant engineering value for efficient heat dissipation of high-power electronic equipment, structural reinforcement of engineering systems under extreme loads.