The ATI Destination Zero roadmap highlights fuel cells as a key future propulsion and power technology. One of the biggest challenges with realising the use of fuel cells within an aerospace environment is thermal management. In particular, radiators for fuel cells must be able to reject significant quantities of heat with only a small temperature difference. With current technology this results in heavy heat exchangers that contribute significant drag to the aircraft. This represents an opportunity for innovative heat exchanger designs and manufacturing processes that can improve upon current state-of-the-art, which this project intends to achieve through its metal binder-jetting technologies. Established methods like laser-powder bed fusion struggle due to their slow and costly nature, both in terms of initial investment and ongoing operational expenses. Metal binder jet printing (MB-J) is a lower-cost option and offered faster production. However, this process has traditionally been limited to niche applications that require fine feature detail, but very small part sizes -- e.g. medical devices. This limitation comes from the high level of shrinkage the part undergoes during the sintering stage. Qdot has been developing an alternative processing route for this technology that enables much larger part sizes to be produced, whilst retaining its many benefits. Instead of trying to print large parts sizes, that inevitably fracture or crack, we divide a design into several smaller units and then use a process called co-sintering to bind them back together. This approach doesn't require line of site, or any additional machinery or bonding agents and, if done correctly, will produce a final part with no visible bonding surfaces. A key issue with standard binder jet processes lies in their use of polymeric binders to hold powder bed particles together, leading to porosity and shrinkage during the subsequent burnout phase. This compromises the quality, resolution, and geometry of the final parts, driving up costs and limiting scalability. To address these challenges, Atomik AM introduces reactive binders composed of the actual build material, rather than sacrificial polymers. By incorporating novel reactive organometallics along with metal micro and nano-particles, these binders can chemically fuse powder beds into 3D structures, offering several advantages such as: enhanced strength, improved density, lower sintering temperature and reduced shrinkage. The goal of this project is deign and build a high-performance fuel cell radiator that demonstrates the capability of Qdot's co-sintering method in combination with Atomik's novel reactive binders.

Qdot Technology and Meta Additive will work together to develop a heat exchanger design, and manufacturing process, taking advantage of hierarchical binder jetting. The project is applying novel, aluminium binder-jetting technology for the thermal management of eVTOL aircraft systems. Opening the design space, and scalability of the process will result in high-performance, and high-efficiency, heat exchangers.