Basic investigations of the preparation and properties of in-situ Al3Ti reinforced aluminium cast alloys

• Applicant: Professorin Dr.-Ing. Carolin Körner
• Subject Area: Metallurgical, Thermal and Thermomechanical Treatment of Materials ; Mechanical Properties of Metallic Materials and their Microstructural Origins
• Term: from 2018 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 412132208

Limiting for the use of aluminum castings is often not their strength, but the stiffness of the alloy. The aim of this project is therefore to increase significantly the stiffness of aluminum casting alloys by in situ formation of the very stiff intermetallic phase Al3Ti. Due to the low solubility of titanium in the aluminum melt, this is not possible by conventional melt metallurgy. In order to generate micrometer sized Al3Ti particles, an in-situ reaction of Ti powder particles (about 50 μm) with liquid aluminum to Al3Ti combined with a novel high-shear unit is used. The significant increase in volume associated with the conversion of titanium to Al3Ti and the resulting high stresses are expected to lead to a very fine fragmentation of the Al3Ti phase into micrometer-sized particles. These particles will be detached from the initial titanium phase and effectively distributed within the melt due to the high shear forces applied by the shear unit. The formation kinetics of the in-situ reinforcement phase and its reinforcement effect in aluminum cast alloys is fundamentally analyzed. The influence of typical die casting alloying elements such as Si and Mg is investigated. Based on this knowledge, the ultimate aim is to design an in-situ reinforced aluminum alloy whose stiffness exceeds significantly that of commercial die casting alloys.

• DFG Programme: Research Grants