Nanojoining of steels with Cu nanopastes

• Applicant: Dr.-Ing. Susann Hausner
• Subject Area: Mechanical Properties of Metallic Materials and their Microstructural Origins ; Joining and Separation Technology
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 571173945

The aim of the project is to investigate the joining of steels at low temperatures using Cu nanopastes. Due to the reduced surface-to-volume ratio of the Cu nanoparticles in the nanopastes, lower joining temperatures are possible compared to brazing with Cu fillers, for example. This prevents undesirable effects that can occur when brazing steels, such grain growth, general changes or destruction of a specifically adjusted microstructure of the steels with corresponding properties, carbide formation and molten metal attack. The aim of the project is to join three different steels with Cu nanopastes with at least comparable mechanical properties compared to brazing with a pure copper filler, whereby the joining temperatures of the nanojoining process are below the brazing process. For this purpose, Cu nanopastes adapted for joining steels have to be developed and characterized. The Cu nanopastes are used for joining steels by varying different process parameters (temperature, holding time, joining pressure). Various characterization methods will be used to gain a deeper understanding of the processes involved in joining. The nanoparticles, the pastes and the produced joints will be characterized in detail, whereby in addition to standard investigations such as microstructure, tensile shear strength and fractography, special features such as fatigue strength tests of the joints, in-situ microtensile tests of the joint seam and in-situ microbending tests of the joints will be carried out.

• DFG Programme: Research Grants