Filler metals of which classification are best suited for joining copper-nickel?

Filler metals classified as BAg are specifically designed for use with copper-nickel alloys. These are high-silver-content brazing alloys that provide excellent joint strength and corrosion resistance, making them particularly suitable for applications involving dissimilar metals such as copper and nickel. The BAg classification is known for its superior flow characteristics and ability to create strong, ductile joints, which are essential when working with copper-nickel material.

In contrast, other classifications such as BAl, BR, and AgCu might not have the same level of compatibility or performance with copper-nickel alloys. BAl fillers are aluminum-based and primarily used for aluminum alloys. BR refers to bronze, which is not ideal for joining copper-nickel due to its different melting points and potential for creating brittle joints. AgCu alloys contain copper and silver and might not provide the necessary attributes for effective bonding with copper-nickel compared to BAg. This is why BAg is the preferred choice for such applications.