AWS BAu-3 (P00350) Filler Metal
AWS BAu-3 is a gold-based filler metal for brazing. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. BAu-3 is the AWS designation for this material. P00350 is the UNS number.
It has a moderately low density among gold-based braze fillers. In addition, it has the highest heat capacity and the highest tensile strength.
The graph bars on the material properties cards below compare AWS BAu-3 to: gold-based braze fillers (top), all alloys in the same category (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.
Thermal Properties
Brazing Temperature
1030 to 1090 °C 1880 to 2000 °F
Latent Heat of Fusion
160 J/g
Melting Completion (Liquidus)
1030 °C 1880 °F
Melting Onset (Solidus)
970 °C 1790 °F
Specific Heat Capacity
300 J/kg-K 0.071 BTU/lb-°F
Thermal Expansion
16 µm/m-K
Other Material Properties
Density
13 g/cm3 780 lb/ft3
Elastic (Young's, Tensile) Modulus
110 GPa 16 x 106 psi
Poisson's Ratio
0.37
Shear Modulus
41 GPa 5.9 x 106 psi
Tensile Strength: Ultimate (UTS)
220 MPa 32 x 103 psi
Common Calculations
Stiffness to Weight: Axial
5.0 points
Stiffness to Weight: Bending
13 points
Strength to Weight: Axial
4.9 points
Strength to Weight: Bending
6.4 points
Thermal Shock Resistance
8.7 points
Alloy Composition
| Cu | 60.9 to 63 | |
| Au | 34.5 to 35.5 | |
| Ni | 2.5 to 3.5 | |
| 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