AlSi10Mg Heat Sinks for Passive Cooling: Convective–Radiative Performance of Finned and Triply Periodic Minimal Surface Designs via Laser Powder Bed Fusion

Increasing power densities in electronic systems require efficient passive thermal-management solutions. This study numerically compares five DMLS-compatible AlSi10Mg heat-sink architectures: perforated planar-fin, curved radial-fin, Schwarz P, BCC diamond and gyroid designs. Conjugate heat-transfer simulations incorporating conduction, natural convection and surface radiation were performed under an identical 18 W thermal load. Performance was evaluated using surface temperature, thermal resistance, temperature uniformity and convective–radiative heat dissipation. The gyroid achieved the lowest average surface temperature (82.02 °C) and combined thermal resistance (3.30 °C W−1), whereas the BCC diamond provided the greatest temperature uniformity (UI = 0.035). Radiation contributed 46–73% of total heat dissipation and was highest for the gyroid architecture. The results demonstrate that increased surface area alone does not ensure improved passive cooling; thermal performance depends on the coupled effects of topology, airflow accessibility and radiative heat exchange. Gyroid TPMS architectures therefore provide a promising DMLS-compatible approach for passive thermal management.