UNS C77300 (RBCuZn-D) Filler Metal
C77300 nickel silver is a copper-based filler metal for brazing. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. RBCuZn-D is the AWS designation for this material. C77300 is the UNS number.
It has the highest tensile strength and a moderately high melting temperature among copper-based braze fillers.
The graph bars on the material properties cards below compare C77300 nickel silver to: copper-based braze fillers (top), all copper alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Elastic (Young's, Tensile) Modulus
110 GPa 16 x 106 psi
Poisson's Ratio
0.3
Shear Modulus
42 GPa 6.2 x 106 psi
Tensile Strength: Ultimate (UTS)
540 MPa 78 x 103 psi
Thermal Properties
Brazing Temperature
940 to 980 °C 1720 to 1800 °F
Latent Heat of Fusion
180 J/g
Maximum Temperature: Mechanical
130 °C 270 °F
Melting Completion (Liquidus)
940 °C 1720 °F
Melting Onset (Solidus)
920 °C 1690 °F
Specific Heat Capacity
390 J/kg-K 0.094 BTU/lb-°F
Thermal Expansion
20 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
5.5 % IACS
Electrical Conductivity: Equal Weight (Specific)
6.3 % IACS
Otherwise Unclassified Properties
Base Metal Price
26 % relative
Density
7.9 g/cm3 490 lb/ft3
Embodied Carbon
3.5 kg CO2/kg material
Embodied Energy
56 MJ/kg 24 x 103 BTU/lb
Embodied Water
310 L/kg 38 gal/lb
Common Calculations
Stiffness to Weight: Axial
7.7 points
Stiffness to Weight: Bending
20 points
Strength to Weight: Axial
19 points
Strength to Weight: Bending
19 points
Thermal Shock Resistance
17 points
Alloy Composition
| Cu | 46 to 50 | |
| Zn | 37.9 to 45 | |
| Ni | 9.0 to 11 | |
| Si | 0.040 to 0.25 | |
| P | 0 to 0.25 | |
| Pb | 0 to 0.050 | |
| Al | 0 to 0.010 | |
| res. | 0 to 0.5 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
AWS A5.8: Specification for Filler Metals for Brazing and Braze Welding
Properties and Selection: Nonferrous Alloys and Special-Purpose Materials, ASM Handbook vol. 2, ASM International, 1993