Work

Topology-optimized heat sinks with superior thermo-mechanical properties fabricated by laser powder bed fusion

Year: 2024

Type: article

Abstract: Heat sinks with enhanced thermo-mechanical properties play a critical role in modern consumer devices for efficient heat dissipation. In this study, a radial heat sink with a dendritic structure was developed using a density-based topology optimization (TO) method to enhance radial heat dissipation. Finite element analysis revealed that the TO-designed heat sink exhibited up to a 40 % increase in radial heat transfer capacity compared to conventional fin heat sinks. The heat sink was fabricated by 316L stainless steel via laser powder bed fusion and subsequently coated with a copper layer through electrochemical deposition . During heat dissipation tests, the copper-plated TO heat sink reached a steady state more rapidly and achieved the highest heat transfer efficiency, with a heat flow of 658 J at an airflow rate of 30 L/min. Flow characteristic analysis revealed that this efficiency enhancement was primarily due to larger vortices and secondary flows generated by the unique TO structure. In the compression test, the TO heat sink demonstrated a 70 % increase in yield strength, attributed to horizontal shear deformation, which differs from the 45° shear deformation observed in finned heat sinks and prevents early fracture at the boundary. This study introduces a novel approach to optimizing and fabricating heat sink structures with superior thermo-mechanical properties.

Source: Applied Thermal Engineering

DOI: 10.1016/j.applthermaleng.2024.125359