AWS BAu-5 (P00300) Filler Metal
AWS BAu-5 is a gold-based filler metal for brazing. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. BAu-5 is the AWS designation for this material. P00300 is the UNS number.
It has a moderately low density among gold-based braze fillers. In addition, it has a fairly high melting temperature and a moderately high tensile strength.
The graph bars on the material properties cards below compare AWS BAu-5 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
1170 to 1230 °C 2130 to 2250 °F
Latent Heat of Fusion
180 J/g
Melting Completion (Liquidus)
1170 °C 2130 °F
Melting Onset (Solidus)
1140 °C 2080 °F
Specific Heat Capacity
280 J/kg-K 0.067 BTU/lb-°F
Thermal Expansion
12 µm/m-K
Other Material Properties
Density
13 g/cm3 820 lb/ft3
Elastic (Young's, Tensile) Modulus
140 GPa 20 x 106 psi
Poisson's Ratio
0.37
Shear Modulus
50 GPa 7.2 x 106 psi
Tensile Strength: Ultimate (UTS)
210 MPa 30 x 103 psi
Common Calculations
Stiffness to Weight: Axial
5.8 points
Stiffness to Weight: Bending
13 points
Strength to Weight: Axial
4.5 points
Strength to Weight: Bending
6.0 points
Thermal Shock Resistance
9.0 points
Alloy Composition
| Ni | 35.5 to 36.4 | |
| Pd | 33.5 to 34.5 | |
| Au | 29.5 to 30.5 | |
| res. | 0 to 0.15 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Further Reading
AWS A5.8: Specification for Filler Metals for Brazing and Braze Welding