Nickel brazing alloys are nickel-based filler metals used for joining metal components in high-temperature applications. These alloys are specifically designed for critical applications requiring high strength, corrosion resistance, and high-temperature durability. They typically contain nickel along with elements such as chromium (Cr), boron (B), silicon (Si), phosphorus (P), and sometimes palladium (Pd).
Key Properties
High-Temperature Resistance: Nickel brazing alloys can withstand very high operating temperatures, making them ideal for applications like jet engines, turbines, and heat exchangers.
Corrosion and Oxidation Resistance: Thanks to elements like chromium, they exhibit exceptional resistance to oxidizing and corrosive environments.
High Mechanical Strength: Joints made with these alloys can have mechanical properties comparable to, or sometimes even superior to, the base metals.
Wetting Ability: During the brazing process, the molten alloy spreads well over the surfaces to be joined, forming strong metallurgical bonds.
Brazing in Vacuum or Protective Atmosphere: Most nickel brazing alloys are typically brazed in a vacuum or an inert gas (e.g., argon) atmosphere to prevent oxide formation and ensure optimal performance.
Areas of Use
Nickel brazing alloys are used in many high-tech and demanding sectors, including aerospace, energy (especially gas turbines), automotive (turbochargers), and the chemical industry. Typical applications include:
Jet Engine Components: Turbine blades, nozzles, and combustion chambers.
Heat Exchangers: Components operating under high temperature and pressure.
Vacuum Tubes and Electronic Components: Precision applications requiring high reliability.
Nuclear Applications: Components where corrosion resistance and long lifespan are expected.
Joining Superalloys: They are frequently preferred for brazing nickel, cobalt, and iron-based superalloys.
Nickel brazing alloys offer an indispensable solution for joining metallic structures with complex geometries and high-performance expectations.
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AWS A5.8
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Ni %
|
Cr %
|
Fe %
|
Si %
|
B %
|
P %
|
C %
|
Cu %
|
W %
|
Mn %
|
Other
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Melting Range
(ºC)
|
Description
|
|
BNi-1
|
73
|
14
|
4,5
|
4,5
|
3
|
0,02
|
0,8
|
-
|
-
|
-
|
-
|
977
|
Used for brazing stainless steels, superalloys at high temperatures.
|
|
BnNi-1a
|
74
|
14
|
4,5
|
4,5
|
3
|
0,02
|
0,06
|
-
|
-
|
-
|
-
|
977
|
Similar to BNi-1 but with lower carbon content.
|
|
BNi-2
|
83
|
7
|
3
|
4,5
|
3
|
0,02
|
0,06
|
-
|
-
|
-
|
-
|
971
|
Alloy with low brazing temperature. Ideal for thick parts of nickel & cobalt base alloys. Available in foil and preforms.
|
|
BNi-3
|
92
|
-
|
0,5
|
4,5
|
3
|
0,02
|
0,06
|
-
|
-
|
-
|
-
|
982
|
Lower temperature brazing of highly stressed parts, close tolerances. Available in foil and preforms.
|
|
BNi-4
|
93
|
-
|
1,5
|
3,5
|
2
|
0,02
|
0,06
|
-
|
-
|
-
|
-
|
982
|
Produces larger, more ductile fillets, for larger gaps.
|
|
BNi-5
|
71
|
19
|
-
|
10
|
0,03
|
0,02
|
0,06
|
-
|
-
|
-
|
0,1
|
1080
|
High silicon content good for narrow, deep joints.
|
|
BNi-5a
|
72
|
19
|
0,5
|
7
|
1,2
|
0,02
|
0,1
|
-
|
-
|
-
|
-
|
1055
|
Available in foil and preforms.
|
|
BNi-5b
|
76
|
15
|
-
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7,3
|
1,4
|
-
|
0,06
|
-
|
-
|
-
|
-
|
1030
|
Excellent oxidation/corrosion resistance.
|
|
BNi-6
|
89
|
-
|
-
|
-
|
-
|
11
|
0,06
|
-
|
-
|
-
|
-
|
877
|
An eutectic nickel brazing alloy with a low melting point. Available in foil and preforms.
|
|
BNi-7
|
76
|
14
|
0,2
|
0,1
|
0,02
|
10
|
0,06
|
-
|
-
|
0,04
|
-
|
888
|
Eutectic nickel brazing alloy with chromium
|
|
BNi-8
|
65
|
-
|
-
|
7
|
-
|
0,02
|
0,06
|
4,5
|
-
|
23
|
-
|
982
|
Manganese content requires special brazing procedures
|
|
BNi-9
|
80
|
15
|
1,5
|
-
|
3,7
|
0,02
|
0,06
|
-
|
-
|
-
|
-
|
1055
|
An eutectic nickel brazing alloy with a high melting point. Available in foil and preforms.
|
|
BNi-10
|
62
|
12
|
3,5
|
3,5
|
2,5
|
0,02
|
0,5
|
-
|
16
|
-
|
-
|
970
|
|
|
BNi-11
|
68
|
10
|
3,5
|
3,5
|
2,5
|
0,02
|
0,4
|
-
|
12
|
-
|
-
|
970
|
|
|
BNi-12
|
64
|
25
|
0,2
|
0,1
|
0,02
|
10
|
0,06
|
-
|
-
|
-
|
0,1
|
888
|
High chromium content
|
|
BNi-13
|
78
|
8
|
0,4
|
4
|
3
|
0,02
|
0,06
|
2,5
|
-
|
-
|
Ay 2 - Nb 2
|
970
|
|
|
BNi14
|
60
|
29,5
|
-
|
4
|
-
|
6
|
-
|
-
|
-
|
-
|
-
|
950
|
|
|
NİPal
|
50
|
10,5
|
-
|
0,5
|
3
|
-
|
-
|
-
|
-
|
-
|
Pal 36
|
820
|
For vacuum brazing.
|
|
BTi-1
|
74
|
16
|
8
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
Ti 0,3-0,5
|
1355
|
|
|
BCo-1
|
17
|
19
|
1
|
8
|
0,8
|
0,02
|
0,4
|
-
|
4
|
-
|
Co 49,8
|
1120
|
|