Pool Boiling Heat Transfer Enhancement with Porous Fin Arrays Manufactured by Selective Laser Melting

Advanced cooling solutions are crucial for the further development of modern technologies. Additive manufacturing (AM) helps to remove many of the conventional design constraints and thereby enables the realization of novel heat sink topologies and geometries that lead to enhanced thermal performance. In this study, porous fin arrays with minimum cavity and channel size of 0.3mm are designed and manufactured using Selective Laser Melting (SLM) technology. AlSi12 alloy powders are adopted to print directly on the copper base. Stable connection is achieved between two materials and thermal resistance is reduced to minimum. The heat transfer performance of heat sinks with different porous layers are evaluated through pool boiling experiments with deionized water. The benchmark test involves a plain copper surface with a footprint of 10×10mm, same as the base used for additive manufacturing. High speed visualization results are combined with the measured boiling data to assess the two-phase heat transfer performance of heat sinks. Superior heat removal performance is achieved with SLM manufactured porous fin arrays with the highest heat transfer coefficient (HTC) enhancement of 80% and critical heat flux (CHF) enhancement of more than 170%. The performance boost is mainly attributed to the larger number of nucleation sites, increased heat transfer area, capillary-assisted suction, and separated liquid-vapor pathways associated with the porous fin array designs. The present study showcases the combination of complex structure design with SLM technology and would provide useful insight for the development of future high performance heat sink designs and the optimization of AM process.