Radiation cooling for heat sinks with high emissivity lanthanum aluminate ceramic coating

The increasing miniaturization and densification of electronic components have increased the demands for efficient heat sinks to dissipate the dense heat generated by these small components. However, owing to the limitations of the substrate material of heat sinks, optimizing the fin structure and its arrangement to enhance heat conduction and convection remains a challenge. In this study, the temperature change of hot water in a 304 steel barrel with and without a La0.9Ca0.1Al0.9Fe0.1O3 (LAF) coating was studied. The results demonstrated that the cooling rate of hot water in the barrel coated with LAF coating increased by 28%. Furthermore, a high-emissivity LAF ceramic coating (0.91) was applied to an aluminum heat sink, and the heat transfer performance of the heat sink with and without the LAF coating was studied. The experimental results showed that the equilibrium temperature of the LAF-coated heat sink was reduced by ∼8 °C. Additionally, the LAF coating increased the total heat transfer coefficient by 20% and reduced the thermal resistance by 18%. The proportion of radiation heat transfer on the surface of the heat sink increased with the LAF coating, which accounted for 44% of the total heat transfer coefficient. Thus, LAF coatings have the potential to effectively improve the heat-transfer performance of thermal devices with different metals.