BrazeLet® Ni5S-8701

Nickel-based brazing alloy

The nickel-based brazing alloy BrazeLet BNi5 has good wetting behaviour on stainless steels and nickel-based superalloys and is suitable for brazing in vacuum or protective atmospheres (hydrogen or argon). The high level of alloyed chromium results in a good hot gas and acid corrosion resistance. The high melting range of BrazeLet BNi5 makes it suitable for applications working at very high temperatures, for instance EGR coolers for trucks, automotive metal catalytic converters and turbine vanes. It is also a commonly used filler material for industrial heat exchangers. Joint properties can be further improved by employing a diffusion hold after brazing.

The solvent based brazing paste BrazeLet Ni5S-8701 can be used for spraying structured plates, typically found in flat heat exchanger designs. It ensures reliable coating over time without drying the spraying nozzles. BrazeLet Ni5S-8701 has no settlement, and no stirring is needed in the equipment. However, when opening a can from stock it is always recommended to stir the paste.

The sprayed parts can be dried with standard drying process (hot air) at 120 – 170 °C. The drying time depends on thermal mass, parts design and the used furnace and thus needs to be established. After drying, the paste has excellent adhesion to the metal sheet.

     
 

Nominal composition: Ni – 19Cr – 10.1Si
Powder type: Gas atomised
Melting range: 1080 – 1135 °C
Minimum brazing temperature: 1150 °C
Recommended gap clearance: 30 – 100 µm
Applicable specifications: AMS4782, ISO 17672 Ni650, AWS A5.8M/A5.8 BNi-5, GE B50TF81, ISO 3677 B-Ni71CrSi-1080/1135

Solvent type: Oil
Metal content: 87 wt%
Particle size: <63 µm
Recommended drying temperature: 120 – 170 °C (250 – 340 °F)
Evaporation temperature of binder: 350 – 450 °C (660 – 840 °F)
Typical Brookfield viscosity (2.5 rpm @ 20 °C): 25 Pas (T-spindle B)
Typical density: 3.6 g/cm3

 
     

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