Novel Design Method for Manufacturing Internal Cooling Channels Additively with a Functional Support Structure

Laser Powder Bed Fusion (PBF-LB/M) is a popular additive manufacturing (AM) technology for producing complex metal components. This layer-by-layer manufacturing process enables the production of intricate internal structures that conventional manufacturing (CM) processes cannot manufacture. Heat exchangers and heat sinks represent an area of application that can benefit significantly from novel internal structures. Due to the geometric freedom offered by PBF-LB/M, new solutions are possible for designing heat sinks, such as complex flow paths or increased surface-to-volume ratio, which can be used to increase heat transfer efficiency. Despite the design freedom offered by PBF-LB/M, design restrictions also need to be considered. One example of these restrictions is the requirement for support structures while manufacturing overhang features. Internal structures are an example of such features. The support structures must be mechanically removed after manufacturing, which becomes complicated or sometimes impossible, particularly for internal structures. To fully exploit the design freedom, this work focuses on a novel design method to enable support-free production of complex internal cooling structures via PBF-LB/M. The proposed solution in this work is to use the necessary support structures during manufacturing as the cooling structures, which can be adapted to the requirements of the heat sinks or heat exchangers to increase thermal efficiency. In this work, five cooling structures are investigated using conjugate heat transfer (CHT) simulation to maximize the ratio of heat transfer to pressure loss. Test samples are manufactured from AlSi10Mg via PBF-LB/M and examined using optical measurements to validate the manufacturability and dimensional accuracy. Finally, a cylinder head is used to demonstrate how a cooling structure suitable for a real-life application can be designed using the proposed design methodology in this work.