Duration: 18 months
One of the biggest challenges in propulsion systems is managing the extreme temperatures encountered in a thruster nozzle. Thruster nozzles in space-crafts can reach temperatures exceeding 2,500°C, threatening to melt the nozzle. While rhenium is often the preferred structural material due to its excellent high-temperature strength, it lacks from oxidation resistance. Therefore typically Iridium coatings are applied to address this issue. One of the challenges today is that the formation of rhenium nozzles is typically involving cost intensive manufacturing techniques and today most of the suppliers are non European. This project explores a novel net shape manufacturing method for producing high-performance rhenium nozzles for space propulsion systems. Instead of using the expensive and time consuming method via Chemical Vapor Deposition (CVD) the nozzles will be created directly from powder. The manufacturing concept uses a feedstock based process to fabricate a mixture between suitable rhenium powders with a photo-polymer which allows the shaping of 3D parts. Following to the shaping process a debinding step is combined with a sintering step to get the final size of the nozzle. This method allows to fabricate very complex geometries including dedicated grid type structures (as illustrated in the image for stainless steel). The goal of the project is to assess this manufacturing method for different geometries. One of the challenges and risks is the identification of suitable raw materials which allow the shaping and to obtain a full dense part after the sintering. The advantage is, that in this particular case only the material which is required for the nozzle is consumed. All other feedstock material can be re-used. Therefore the waste of rhenium generated is in this case very low.
