Aerospace Material Specification 4770 is silver alloy BAg-1a in welding wire, welding rod, powder, and paste.
BAg-1a is a brazing filler metal that is free-flowing with higher fluidity. This alloy can be used on most iron, copper and nickel-based alloys. Due to its narrow melting range this filler metal is less sensitive to the heating rate and therefore should not separate into low/high melting constituents.
Ag: 50% | Cd: 18% | Zn: 16.5% | Cu: 15.5%