In this context, work will be carried out on two strategies based on metal alloys that have to be printed. First, a process will be developed for printing parts with Ni-based superalloys. Second, a different type of process will be developed to print parts of aluminium alloys.
The additive manufacturing of aeronautical components with superalloys is carried out using technologies such as selective laser melting (SLM), which have high associated costs and difficulties in handing the raw material in the form of powders. The project will explore an alternative based on the use of an FDM printer, with a cost two orders of magnitude lower than that of SLM printers, based on the superalloy in the form of pellets or granules comprised of metal powders of alloys of interest and a polymer binder that will act as the vehicle during the printing. This approach has the advantage of not requiring high temperatures for the printing. In addition, the raw material exists in commercial form as it is the same as that used in metal injection moulding (MIM) processes. The printed parts must undergo subsequent processes to eliminate the polymer and sintering.
The printing of aluminium alloys will involve the development of a printing system based on the concept of paste extrusion printers that are used for polymers, ceramic suspensions or food printing, but could work at temperatures close to 600oC, approximately. The material that has to be extruded will be in the form of bars and has a microstructure designed specifically to minimise the temperature and effort of printing and improve the properties of parts printed using this system. For this reason, the development of the system for printing aluminium alloys will require optimisation of the starting material, particularly characterisation of the rheology of the material and determination of the processing window.
The project is funded by the Spanish National Plan for Scientific and Technical Research and Innovation 2017–2020, within the Spanish Research, Development and Innovation Programme oriented at the Challenges of Society. It has a budget of 157,000 euros and will be completed in 2021.