title: Soldering of Carbon Materials Using Transition Metal Rich Alloys.
abstract: Joining of carbon materials via soldering has not been possible up to now due to lack of wetting of carbons by metals at standard soldering temperatures. This issue has been a severely restricting factor for many potential electrical/electronic and mechanical applications of nanostructured and conventional carbon materials. Here we demonstrate the formation of alloys that enable soldering of these structures. By addition of several percent (2.5-5%) of transition metal such as chromium or nickel to a standard lead-free soldering tin based alloy we obtained a solder that can be applied using a commercial soldering iron at typical soldering temperatures of approximately 350 °C and at ambient conditions. The use of this solder enables the formation of mechanically strong and electrically conductive joints between carbon materials and, when supported by a simple two-step technique, can successfully bond carbon structures to any metal terminal. It has been shown using optical and scanning electron microscope images as well as X-ray diffraction patterns and energy dispersive X-ray mapping that the successful formation of carbon-solder bonds is possible, first, thanks to the uniform nonreactive dispersion of transition metals in the tin-based matrix. Further, during the soldering process, these free elements diffuse into the carbon-alloy border with no formation of brazing-like carbides, which would damage the surface of the carbon materials.
authors.affiliation: Department of Materials Science and Metallurgy, University of Cambridge , 27 Charles Babbage Road, CB3 0FS, Cambridge, U.K.
authors.forename: Marek
authors.initials: M
authors.lastname: Burda
authors.affiliation: Department of Materials Science and Metallurgy, University of Cambridge , 27 Charles Babbage Road, CB3 0FS, Cambridge, U.K.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Lekawa-Raus
authors.affiliation: Welding Department, Silesian University of Technology , Konarskiego 18a, 44-100 Gliwice, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Gruszczyk
authors.affiliation: Department of Materials Science and Metallurgy, University of Cambridge , 27 Charles Babbage Road, CB3 0FS, Cambridge, U.K.
authors.forename: Krzysztof K K
authors.initials: KK
authors.lastname: Koziol
keywords: carbon fibers; carbon nanomaterials; soldering alloys; wetting