UNS C55281 (BCuP-3) Filler Metal
C55281 copper is a copper-based filler metal for brazing. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. BCuP-3 is the AWS designation for this material. C55281 is the UNS number.
The graph bars on the material properties cards below compare C55281 copper 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 15 x 106 psi
Poisson's Ratio
0.34
Shear Modulus
40 GPa 5.8 x 106 psi
Tensile Strength: Ultimate (UTS)
190 MPa 28 x 103 psi
Thermal Properties
Brazing Temperature
720 to 820 °C 1320 to 1500 °F
Latent Heat of Fusion
190 J/g
Maximum Temperature: Mechanical
200 °C 390 °F
Melting Completion (Liquidus)
810 °C 1500 °F
Melting Onset (Solidus)
640 °C 1190 °F
Specific Heat Capacity
400 J/kg-K 0.1 BTU/lb-°F
Thermal Expansion
16 µm/m-K
Otherwise Unclassified Properties
Density
8.7 g/cm3 540 lb/ft3
Embodied Carbon
7.0 kg CO2/kg material
Embodied Energy
110 MJ/kg 48 x 103 BTU/lb
Common Calculations
Stiffness to Weight: Axial
6.9 points
Stiffness to Weight: Bending
18 points
Strength to Weight: Axial
6.1 points
Strength to Weight: Bending
8.5 points
Thermal Shock Resistance
7.7 points
Alloy Composition
| Cu | 88.5 to 89.4 | |
| P | 5.8 to 6.2 | |
| Ag | 4.8 to 5.2 | |
| res. | 0 to 0.15 |
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