Contamination tolerant hypo- and hypereutectic Al-Si-alloys for additive manufacturing

• Applicants: Dr.-Ing. Nils Ellendt; Dr.-Ing. Anastasiya Tönjes
• Subject Area: Materials in Sintering Processes and Generative Manufacturing Processes ; Mechanical Process Engineering
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 493860861

Aluminum, as a lightweight metal, is being used in a wide range of applications in the aerospace and automotive industries. However, the production of primary aluminum is very energy intensive. The recycling of aluminum introduces different contaminations such as for example iron. In aluminum alloys, iron is known to form intermetallic phases, which can lead to embrittlement of the bulk material if their size becomes too large. Synthesis with high cooling rates, like additive manufacturing, may offer an interesting recycling route. This may allow additive manufacturing to be a central process in sustainable closed material chains.Thermophysical properties, such as surface tension and viscosity, are of great importance for the process. However, even small amounts of contamination can have a large effect on these properties. In our project, the effect of Fe contamination on two Al-Si alloys with silicon concentrations of 10 wt.% (hypoeutectic) and 20 wt.% (hypereutectic) will be investigated. While AlSi10 is a common alloy for LPBF, the process window for processing becomes smaller with increasing silicon content. A systematic variation of Fe contamination allows to understand its effect on the base of thermophysical properties, meltpool conditions, phase formation and defect structures of manufactured parts.If the relationships between contamination, thermophysical properties, phase formation and process windows are known, contamination can be compensated by adjusted process conditions.

• DFG Programme: Priority Programmes
• Subproject of: SPP 2122: Materials for Additive Manufacturing