Gold-copper Orobraze™ brazing filler metals are high purity filler metals showing good resistance to oxidation at elevated temperatures and excellent corrosion resistance in many chemical environments.

Gold-copper Orobraze™ filler metals are suitable for use in the fabrication of vacuum tube / thermionic valve devices as both gold and copper have low vapor pressures under the elevated temperature and levels of vacuum seen in such items. In addition, the filler metals can be manufactured such that they contain only minimum levels of volatile elements, and can therefore be supplied to meet the requirements of EN 1044 - V1 grade (vacuum grade 1 materials).

All the gold-copper Orobraze™ filler metals have relatively short melting ranges and free flowing characteristics, and come with ever increasing series of melting ranges allowing their use in step brazing operations. Typical joint gaps are between 0.025-0.1mm depending on parent materials and joint configuration.

Gold-copper Orobraze™ filler metals can produce ductile joints without excessive inter-alloying / erosion of the parent metals, which is advantageous when brazing thin walled structures. They form small radius smooth fillets at the joint edges.

Typical applications are for brazing vacuum tube / thermionic valve devices. Gold-copper Orobraze™ filler metals exhibit good wetting on copper, nickel, iron, cobalt, molybdenum, niobium, tungsten and their alloys, and due to their good ductility are also useful for brazing metallized ceramics.

Information provided by Johnson Matthey Metal Joining