Additive Manufactured Titanium-Ammonia Heat Pipes for Thermal Management of Space Electronic Devices

In the frame of the project AO-1-6896 ‘370-400 K “gravity-friendly” heat pipe with low freezing temperature’, novel additive manufactured heat pipes were developed and acceptance tested. The technology utilises laser powered bed fusion (LPBF) additive manufacturing (AM) technique to construct titanium heat pipe vessels with integrated micro-scale lattice capillary wick structures. Laser parameter optimisation trials and capillary lift height experimentation enabled miniaturisation of the lattice structure cell size to below the current state-of-the art processes. This enabled a level of capillary pumping against gravity, whilst achieving the specified 30 W direct thermal management of a simulated microprocessor. The AM heat pipe technology is the first of its kind and has been granted European Patent No. 2715265. This paper presents an overview of the technology and gives a comparison against a stainless steel, ammonia heat pipe, with a screen mesh capillary wick structure, that was developed in parallel to the AM heat pipe.