Development of Advanced Manufacturing Technologies for Repairing Next Generation Aeroengines (DEMAND-REPAIR)

The aerospace industry is working towards building a sustainable industry to reduce its environmental impact and effect on climate change. Replacing damaged parts with the new ones is a costly affair, which can be avoided if the parts can be repaired and remanufactured. However, traditional technologies such as electron beam patch welding or high-velocity-oxy fuel or plasma spray are not suitable to effectively repair next generation parts. The extensive heat input from these processes can cause thermal and geometrical distortions and degrade mechanical properties, resulting in an unacceptable risk to safety.

Therefore, new alternative technologies must be explored for repairing such advanced components. The emerging processes of cold spray, high velocity air fuel (HVAF) spray, extreme high speed laser cladding (EHLA) and laser metal deposition-powder (LMDp) have been identified by the consortium as promising surface engineering and additive manufacturing technologies, due to their lower heat input compared with traditional techniques.

All of these emerging technologies make use of powder feedstock material, with the process reliability and deposit quality dependent on well-controlled powder properties (composition, microstructure, morphology, powder size distribution). Ti-6Al-4V powders are typically manufactured via gas atomization and result in a low yield of powders in the desired size distribution. This results in high costs and limits the uptake of many emerging repair and additive manufacturing technologies.

Novel approaches to manufacture of high value Ti-6Al-4V powders will create highly flowable titanium powders with a fine and narrow size distribution at a much lower cost. The process is also expected to result in powders with novel microstructures. While less of a concern for the laser-based repair processes that re-melt particles, such changes to microstructure are expected to increase ductility during deformation and as such, significantly benefit the spray-based processes of HVAF and cold spray.

Therefore, the DEMAND-REPAIR project plans to explore novel advanced manufacturing technologies and innovative titanium powders to repair the next generation aero-engine components.