AWS BCo-1 (R39001) Filler Metal
AWS BCo-1 is a cobalt alloy. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. BCo-1 is the AWS designation for this material. R39001 is the UNS number. It has the lowest melting temperature and a fairly low tensile strength among cobalt alloys.
The graph bars on the material properties cards below compare AWS BCo-1 to other cobalt alloys (top) 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
200 GPa 29 x 106 psi
Poisson's Ratio
0.3
Shear Modulus
78 GPa 11 x 106 psi
Tensile Strength: Ultimate (UTS)
700 MPa 100 x 103 psi
Thermal Properties
Brazing Temperature
1150 to 1230 °C 2100 to 2250 °F
Latent Heat of Fusion
420 J/g
Melting Completion (Liquidus)
1150 °C 2100 °F
Melting Onset (Solidus)
1120 °C 2050 °F
Specific Heat Capacity
480 J/kg-K 0.11 BTU/lb-°F
Thermal Expansion
12 µm/m-K
Otherwise Unclassified Properties
Density
8.1 g/cm3 510 lb/ft3
Embodied Carbon
8.0 kg CO2/kg material
Embodied Energy
110 MJ/kg 48 x 103 BTU/lb
Embodied Water
430 L/kg 51 gal/lb
Common Calculations
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
24 points
Strength to Weight: Bending
22 points
Thermal Shock Resistance
21 points
Alloy Composition
| Co | 46 to 54 | |
| Cr | 18 to 20 | |
| Ni | 16 to 18 | |
| Si | 7.5 to 8.5 | |
| W | 3.5 to 4.5 | |
| B | 0.7 to 0.9 | |
| Fe | 0 to 1.0 | |
| C | 0.35 to 0.45 | |
| Al | 0 to 0.050 | |
| Ti | 0 to 0.050 | |
| Zr | 0 to 0.050 | |
| P | 0 to 0.020 | |
| S | 0 to 0.020 | |
| Se | 0 to 0.0050 | |
| 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