Simsalabim

Motivation

Up to now, metal additive manufacturing has concentrated on laser-based processes such as Laser Cladding or Powder Bed Fusion. These are characterized by a high technology readiness level (TRL), but do not meet all challenges in terms of materials, geometries and productivity. Sinter-based Additive Manufacturing (SBAM) offers a number of advantages, such as the ability to process hard-to-weld materials, a high surface quality and high production rates.

Unlike laser-based methods that melt the material during the process, shaping in sinter-based Additive Manufacturing occurs initially without the input of thermal energy. In Metal Binder Jetting, for example, components are built up layer by layer from powder; an organic binder, which is introduced locally by in ink-jet process, causes the metal particles to stick together. This creates what is known as a green part. The binder is removed again by subsequent heat treatment in the oven (debinding). During the sintering process, the component becomes denser and attains its final properties, although it also experiences geometric shrinkage.

Nickel-based superalloys are materials of strategic importance for the energy and transportation industry and hydrogen technologies. In particular, alloys with a high content of the strength-enhancing γ' phase cannot be processed using laser-based additive manufacturing, but are also challenging in forging or casting. Sintering-based processes offer a promising alternative here.

Objectives and Approach

The still comparatively low technological maturity of SBAM offers great potential for the development of a committed community. Saxon companies in particular have the opportunity to benefit more from the existing scientific expertise in order to drive forward the transfer and commercial use of these pioneering technologies in a targeted manner. The consortium has derived the following objectives from the technological and transfer-related challenges:

• Development of a process chain for sinter-based additive manufacturing of nickel-based alloys up to TRL 5: design, simulation, adjustment of material properties, quality assurance measures
• Shortening the necessary development cycles through more efficient sintering simulation
• Establishment and strengthening of a Saxon network for sinter-based additive manufacturing

Within the project, Fraunhofer IWS is focusing on the metal binder jetting process for nickel-based alloys.

Innovations and Prospects

Sinter-based additive manufacturing, and binder jetting in particular, is one of the fastest growing technologies within additive manufacturing. SIMSALABIM offers companies a scientific basis to better evaluate processes and material properties. This facilitates the development of customized products and the integration of the technology into industry. In addition, the project enables rapid testing of components with regard to their manufacturability and achievable tolerances using simulation. Better networking between the scientific community and industrial users promotes knowledge transfer and helps to open up new potential applications.