Mineral-bound and reusable mold materials for the casting production of aluminum components

• Applicants: Professor Dr.-Ing. Sebastian Müller; Dr. Alexander Wetzel
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing ; Construction Material Sciences, Chemistry, Building Physics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 557137947

Mineral-bound mold materials offer the potential to overcome the disadvantages of conventional metal casting processes and to unlock new application possibilities in casting processes due to their lower reactivity and reduced thermal conductivity during the processing of molten metals in casting procedures. This project is therefore dedicated to the investigation of mineral-bound mold materials for the production of aluminum cast components. These materials are intended to be used as reusable molds (permanent molds) in casting processes. The project aims to bridge, for the first time, the gap between the well-known sand casting methods and the die casting processes based on metallic permanent molds. A key focus of the research lies in correlating the phase composition of the binder matrix as a function of the precursors. The project will investigate how this composition changes under cyclic thermal loads and what impact this has on thermal stability. Through comprehensive microstructural and phase-analytical studies, the influence of specific thermal stress on the binder system of alkali-activated materials will be fundamentally researched, and the suitability of these modified mold materials for use in casting processes will be assessed. Additionally, the research will focus on the influence of aggregates and fibers to further improve thermal stability. Various materials, such as basalt and expanded glass, will be used to modify thermal conductivity and to specifically influence the cooling rate of the cast material. Due to differing properties regarding thermal conductivity, surface and strength, as well as dimensional and positional tolerances of the concrete molds, fundamental knowledge must also be developed concerning suitable mold and casting process design, along with the resulting properties of the cast components. The filling properties of aluminum melts in concrete molds will be studied under different process and geometric conditions. The durability of the concrete molds and the dimensional properties of the cast components will also be analyzed across varying geometries. Numerical simulations will deepen the understanding of mold filling and thermomechanical stresses and will assist in developing suitable methods for designing concrete molds in casting processes. Furthermore, the influence of the casting process on the metallurgical properties of the two aluminum alloys AlSi7Mg0.3 and AlMg10 will be investigated. This work will include the characterization of the microstructure and mechanical properties under the specific conditions of the new casting process. In particular, the effect of grain refiners such as AlB3 and AlB3V3 will be analyzed to reduce grain size and thereby improve the mechanical properties of the resulting components.

• DFG Programme: Research Grants