http://www.handyharmancanada.com/The...tm#Braze%20650

Filler Metal name: Braze 655
Typical Applications: For brazing Invar, Kovar and similar alloys to
copper in vacuum tubes; as jet engine rubbing seals.
Solidus: 1385'F/750'C
Liquidus: 1560'F/850'C
Max. Recom. Brazing Temp. 'F: 1700
Nominal Composition,%: 65Ag 28Cu 5Mn 2Ni
Joint Color as Brazed: White
Density Troy oz/cu in: 5.20
Electrical Characteristics

* Conduct. % IACS: 12.8
* Resistivity microhm-cm: 13.4



I know from reading Ernie's posts Silicon Bronze is recommended (not
the low fuming kind)