CGS sprayed filler coatings for brazing of light weight alloys
Application of cold gas spraying for deposition of braze filler coatings is investigated. Different light weight alloy substrates, i.e. aluminum AA1050, AA3005, AA5754 and AA7022, magnesium AZ91 and titanium TiAl6V4, are used. Filler coating materials depend on the substrate melting temperature. So for aluminum alloys Al12Si and zinc based fillers, for AZ91 pure zinc and for Ti6Al4V different Cu-Ni blends are applied. CGS process parameters are varied with regard to process gas (nitrogen) temperature and pressure, powder feed rate and spray distance. Correlation to process characteristics and economical aspects are given. The usability of the produced filler coatings is shown by different optimized brazing/soldering processes. In case of aluminum braze joints a full metallographical investigation is carried out by optical and scanning electron microscopy as well as EDXS analyses. The gathered results are compared with those of conventional filler material addition, i.e. wire, roll plating and foil.
B. Wielage, T. Grund, S. Ahrens, A. Wank, F. Trommer, Chemnitz / D