What type of filler metal is used for brazing stainless steel, carbon steel, copper, and nickel alloys and is known for its corrosion and heat resistant properties?

• A. Tin (Sn)
• B. Nickel (Ni)
• C. Copper (Cu)
• D. Aluminum (Al)

Answer: (B)

Nickel-based brazing filler metals are chosen when a joint must survive in corrosive environments and at elevated service temperatures across a variety of base metals. Nickel alloys wet stainless steel, carbon steel, copper, and nickel alloys effectively and resist oxidation at brazing temperatures, helping the joint maintain strength and integrity. The high-temperature stability and corrosion resistance of nickel-based fillers mean they form durable, ductile joints with dissimilar metals, which is why they are widely used for this mix of bases. Tin-based fillers melt at lower temperatures but don’t offer the same level of corrosion resistance; copper fillers are best for copper-to-copper joints, and aluminum fillers are intended for aluminum. Thus, nickel-based filler metal best fits the description.