AWS BAu-3 vs. AWS BAu-4
Both AWS BAu-3 and AWS BAu-4 are otherwise unclassified metals. Both are furnished in the as-fabricated (no temper or treatment) condition. They have a modest 38% of their average alloy composition in common, which, by itself, doesn't mean much.
For each property being compared, the top bar is AWS BAu-3 and the bottom bar is AWS BAu-4.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 110 | |
| 110 |
| Poisson's Ratio | 0.37 | |
| 0.4 |
| Shear Modulus, GPa | 41 | |
| 41 |
| Tensile Strength: Ultimate (UTS), MPa | 220 | |
| 200 |
Thermal Properties
| Brazing Temperature, °C | 1030 to 1090 | |
| 950 to 1000 |
| Latent Heat of Fusion, J/g | 160 | |
| 100 |
| Melting Completion (Liquidus), °C | 1030 | |
| 950 |
| Melting Onset (Solidus), °C | 970 | |
| 950 |
| Specific Heat Capacity, J/kg-K | 300 | |
| 190 |
| Thermal Expansion, µm/m-K | 16 | |
| 14 |
Otherwise Unclassified Properties
| Density, g/cm3 | 13 | |
| 17 |
Common Calculations
| Stiffness to Weight: Axial, points | 5.0 | |
| 3.6 |
| Stiffness to Weight: Bending, points | 13 | |
| 9.3 |
| Strength to Weight: Axial, points | 4.9 | |
| 3.2 |
| Strength to Weight: Bending, points | 6.4 | |
| 4.4 |
| Thermal Shock Resistance, points | 8.7 | |
| 9.2 |
Alloy Composition
| Copper (Cu), % | 60.9 to 63 | |
| 0 |
| Gold (Au), % | 34.5 to 35.5 | |
| 81.5 to 82.5 |
| Nickel (Ni), % | 2.5 to 3.5 | |
| 17.4 to 18.5 |
| Residuals, % | 0 | |
| 0 to 0.15 |