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Brazing Alloys
Gold–based brazing alloys are used in industrial brazing, offering improved resistance to oxidation, good mechanical properties of joints at elevated temperatures, and excellent corrosion resistance in challenging environments, when compared to base metal alloys. Of course, due to cost, these alloys tends to be limited to high value applications. Alloys that contain around nickel-gold alloys (20 wt % gold) with the balance made up of chromium, iron and silicon, were developed for the assembly of space shuttle engines as alternatives to conventional nickel-based brazes. The addition of palladium to gold alloys further improves resistance to oxidation at elevated temperatures, as well as the strength of the alloys. These materials are used mostly for joining superalloy and metal components that need to operate in relatively aggressive environments eg jet engines. These alloys can have melting temperatures that reach up to 1200 °C. For more in-depth information on brazing and joining visit the archive of Gold Bulletin. |