Brazing Filler Metal Alloy
A metallic composition with a working temperature above 450 degrees Celsius used for joining components while keeping the base material solid. Typical systems are based on silver, copper, or nickel.
Brazing means: you join two parts with a filler metal that melts below the melting temperature of the base material. The filler metal melts and flows into the gap, it is not plastically deformed. It is important that the joint surfaces are clean and free of oxide, otherwise the filler metal won't wet. The brazing temperature depends on the filler metal and the base material, but you're above 450 °C, otherwise it's soldering. If you get too hot, you can damage the structure of the base material, so keep the time short and choose the filler metal suitable for the application.