Core and mold materials for complex components

Cast salt cores

The excellent properties of cast salt cores with flexural strengths of over 25 MPa and the closed, smooth surfaces, as well as their outstanding water solubility, make salt cores the perfect core material for recasting in die casting. At Fraunhofer IFAM, our scientists are investigating the entire process technology from the material development of the salt mixtures in simulations and laboratory tests, to the production of the salt cores from the melt, to the recasting in the die casting process with aluminum and the dissolution and recycling of the aqueous salt solution in various projects. We place a special focus on the sustainable use of the salt cores and their recycling.

Salt cores are always suitable where cavities have to be created, so the potential for use in plastics processes such as CFRP manufacturing processes (vacuum infusion, RTM, etc.) or plastic injection molding is another addressed field of application.

Our services include:

• Development and characterization of salt mixtures
• Development of casting tools for the production of salt cores by gravity or low-pressure die casting
• Characterization of salt cores (microstructure, mechanical testing, pore analysis, etc.)
• Production and delivery of salt cores for prototypes and small batches
• Recasting of salt cores by die casting
• Casting simulation and process development

Inorganically bonded mold materials

The substitution of organic binders by inorganic systems is the focus of mold material development at Fraunhofer IFAM. This includes, for example, inorganic binders for iron and steel casting or new binder systems for the additive manufacturing of molds and cores for metals with high casting temperatures. The reduction of the required amount of mold material as well as aspects of recycling or landfilling of used mold materials are further focal points of development.

Our services include:

• Custom development and optimization of inorganically bonded mold materials
• Characterization of mold materials
• Execution of casting and demolding tests
• Process development and evaluation
• Development of investment materials for investment casting with block molds

Ceramic cores and inorganically bonded cores

Complex internal geometries are produced in investment casting components or in die casting by lost ceramic cores. Different and sometimes contradictory requirements are placed on the ceramic cores in the various process steps. In the case of die casting, high strength is a prerequisite; in the case of investment casting, sufficient strength is required for wax injection molding as well as good temperature and dimensional stability during firing of the mold shell. After casting, on the other hand, easy demoldability is a prerequisite in order to reduce the time-consuming and cost-intensive effort required for coring. Fraunhofer IFAM conducts research into inorganic binders, for example for cores in sand or gravity die casting or binder development for additive manufacturing of cores, develops cores with adapted pore structures or improved decoring properties, and provides support in casting tests.

Our services include:

• Customized development of inorganically bonded cores
• Testing and evaluation of cores in die casting (sand cores, ceramic cores, salt cores)
• Execution of casting and demolding tests
• Development of cores with adapted properties