TFB 58:  Supreme Materials: Application of Spray Formed Materials

• Subject Area: Materials Science and Engineering ; Materials Science and Engineering
• Term: from 2005 to 2008
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 17015331

Special alloys can be produced as preforms: billets, rings, tubes, and sheets with a new process called Spray Forming . In this process a molten metal stream is atomised by a gas flow. Small droplets are generated and accelerated in the spray cone. During a short flight time the droplets cool down rapidly until they impact on the substrate and solidify. The so-called deposit is built by these droplets. Compared to Continuous Casting , the spray formed material is much more homogenous (reduced micro and macro segregation) and the grain sizes are smaller due to the rapid cooling of the droplets during the flight and impact. This leads to better properties in the final material. Low oxygen content and lower costs are advantages compared to the powder metallurgy route. Spray Forming is always most successful if there is no other process available to produce a special alloy of high quality. The Transfer Unit uses the fundamental results of the Collaborative Research Centre 372 Spray Forming in two projects together with companies to put the process into practice.The improvement of the machining properties of different steels (bearing steel, heat-treatable steel, case-hardening steel) is the aim of the first project, to make soft machining more economical. Conventionally, the sulphur content in the alloy will be increased. However, this will lead to a substantial decrease of the mechanical properties using the conventional production route. In contrast, the spray formed material shows only little losses in the mechanical properties due to the much better distribution and smaller sizes of the manganese sulphides.Despite an increasing industrial interest in spray formed sheets there is no production of spray formed sheets today. The reason is that Spray Forming of sheets is more complex and not fully understood. Therefore, the aim of the second project is the Spray Forming of aluminium sheets. To achieve this aim, the heating and cooling conditions of the process will be studied intensively to make a temperature control of the substrate, the deposit, and finally the reproduction of aluminium sheets possible.

• DFG Programme: CRC/Transfer Units

Completed projects

• T01 - Herstellung von AIMgSi-Legierungen als Flachprodukt (Project Head Uhlenwinkel, Volker )
• T02 - Höherfeste Stähle mit wirtschaftlicher Zerspanbarkeit (Project Heads Bomas, Hubert ;  Zoch, Hans-Werner )

• Applicant Institution: Universität Bremen
• Co-Applicant Institution: Leibniz-Institut für Werkstofforientierte Technologien IWT
• Spokesperson: Professor Dr.-Ing. Hans-Werner Zoch