InssTek, a metal DED technology developer based in Daejeon, South Korea, succeeded in manufacturing a multi-material Functionaly Grade Material, or FGM, rocket nozzle using different metals (aluminum-bronze alloy and stainless steel) in a single print run. This application proves that aerospace components used in extreme environments can be made using the ideal materials with superior characteristics in each different region of the same part. As confirmed by NASA and other space companies, the ability to produce single parts using different metals is expected to be a key enabling technology for the growing space industry market.
Many aerospace components are used in extreme environments. Rocket nozzles in particular have different requirements with many different parameters. For example, the working temperature and heat flow are different in the upper and lower regions of the nozzle, thus the preferred types of materials may vary for each region.
While this has led to an increasing demand to apply different materials in each area of the same part, the ability to safely and effectively bind together the two different materials remains a challenge, with the contact becoming too weak due to the difference in characteristics of each material. Innstek demonstrated that when the composition of the materials is changed gradually, through the precision of metal deposition AM technology, it can produce a more stable material that can withstand harsher conditions in extreme applications.
Thus, Functionally Graded Material (FGM) approach was demonstrated by Insstek as a novel method of combining two metal materials, gradually changing the composition of the two different materials to produce a multi-material part.
Most metal 3D printing technologies such as casting, forging, and cutting, manufacture parts with a single material. However, Direct Energy Deposition (DED) offers a significant advantage by enabling the use of multiple materials. When 3D printing with multi-materials, the most important technology is the “Powder Supply” technology. It should supply stable quantities for a long time throughout the print and also supply multiple powders at the same time, as the properties of a metal alloy can be easily changed by the composition of the different elements. Thus “Accurate Control ” and “Multiple Powder Feeding” technology is essential.
InssTek’s CVM Powder Feeding System technology does just that: it provides a more stable powder supply during the metal 3D printing process. It can be controlled within ±5% of the target amount by monitoring the powder supply in real-time. In addition, it is an optimized technology for manufacturing multi-material parts with a new composition by independently controlling up to six different powders.
InssTek has its own HW, SW, and material processing technologies that can be used to manufacture multi-material parts. Based on these technologies, InssTek succeeded in producing the actual scale rocket nozzle into Functionally Graded Material. Research is underway to apply multi-material parts to diverse fields such as aerospace, marine, and medical industry.
InssTek will be exhibiting at IMTS, in Chicago this September, and at Formnext in Frankfurt, Germany, this November to showcase various metal 3D printing technologies, including its Multi-Material Manufacturing capabilities.