Aerospace Material Specification 4765 covers silver alloy in the form of welding wire, welding rod, powder, and paste. Typically used for joining austenitic steels where joint strength of up to 800°F is required.
Ag: 56% | Cu: 42% | Ni: 2%
Further reading: AMS 4772 silver alloy.
Further reading: AMS 4788 silver brazing filler metal.