Institute for Applied Materials – Materials Science and Engineering

Molding compound development for powder injection molding

For the construction and cost-effective production of components, suitable materials need to fulfill the following criteria: good availability, reproducible material quality, acceptable price and easy processability.

 

Close contoured precision, mass production, variety of shapes and complexity are some of the advantages of components manufactured by powder injection moulding. The processing chain consists of the following sub-steps:

 

  • Compounding of metallic or ceramic powders and binding systems to suitable molding compounds (feedstocks)
  • Simulation and tool fabrication
  • Production of green parts
  • Heat-treatment (debinding and sintering)

One example of the targeted development of modern material systems for applications in energy research is tungsten powder injection moulding:

Tungsten powder injection moulding @ KIT 

Isotropic materials with equiaxed grain orientation, good thermal shock resistance, variety of shapes and high density, are typical properties of powder injection molded tungsten.

By developing new, e.g. particle-reinforced tungsten materials, tailor-made materials and material systems can be produced. The added amount of, e.g. TiC or Y2O3 particles to the tungsten matrix stabilizes the grain boundaries and creates a fine grained structure by suppressing grain growth.

Mechanical properties like ductility and stability are adjustable in a wide range depending on the application.

 

New material innovations
... 4-point bending tests from 20 to 400 °C ...

S. Antusch, et al.: Journal of Nuclear Materials and Energy, 16 (2018), pp. 71-75.

 

In order to achieve the best possible impression and sintering results, it is necessary to optimize the molding compounds with regard to the powder filling level, flow properties and shrinkage behavior.

The further development of powder injection moulding to multi-component micro-powder injection moulding in particular requires alternative binder systems in order to be able to produce loose or solid composites specifically with different materials. This includes:

  • Binder systems based on reaction resins
  • Thermoplastic-wax combinations
  • Water soluble binder components

For any further questions on this topic please contact Mr. Dr. Steffen Antusch.