AWS BAu-4 (P00820) Filler Metal
AWS BAu-4 is a gold-based filler metal for brazing. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. BAu-4 is the AWS designation for this material. P00820 is the UNS number.
The graph bars on the material properties cards below compare AWS BAu-4 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
950 to 1000 °C 1740 to 1840 °F
Latent Heat of Fusion
100 J/g
Melting Completion (Liquidus)
950 °C 1740 °F
Melting Onset (Solidus)
950 °C 1740 °F
Specific Heat Capacity
190 J/kg-K 0.044 BTU/lb-°F
Thermal Expansion
14 µm/m-K
Other Material Properties
Density
17 g/cm3 1090 lb/ft3
Elastic (Young's, Tensile) Modulus
110 GPa 17 x 106 psi
Poisson's Ratio
0.4
Shear Modulus
41 GPa 5.9 x 106 psi
Tensile Strength: Ultimate (UTS)
200 MPa 29 x 103 psi
Common Calculations
Stiffness to Weight: Axial
3.6 points
Stiffness to Weight: Bending
9.3 points
Strength to Weight: Axial
3.2 points
Strength to Weight: Bending
4.4 points
Thermal Shock Resistance
9.2 points
Alloy Composition
| Au | 81.5 to 82.5 | |
| Ni | 17.4 to 18.5 | |
| 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