ASTM B628 Ag-Cu vs. 85-platinum 15-iridium
Both ASTM B628 Ag-Cu and 85-platinum 15-iridium are otherwise unclassified metals. Please note that the two materials have significantly dissimilar densities. This means that additional care is required when interpreting the data, because some material properties are based on units of mass, while others are based on units of area or volume.
For each property being compared, the top bar is ASTM B628 Ag-Cu and the bottom bar is 85-platinum 15-iridium.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 83 | |
| 220 |
| Elongation at Break, % | 1.1 to 17 | |
| 5.5 to 34 |
| Poisson's Ratio | 0.36 | |
| 0.38 |
| Shear Modulus, GPa | 31 | |
| 81 |
| Shear Strength, MPa | 210 to 430 | |
| 370 to 420 |
| Tensile Strength: Ultimate (UTS), MPa | 350 to 760 | |
| 560 to 730 |
Thermal Properties
| Latent Heat of Fusion, J/g | 140 | |
| 110 |
| Melting Completion (Liquidus), °C | 780 | |
| 1820 |
| Melting Onset (Solidus), °C | 780 | |
| 1790 |
| Specific Heat Capacity, J/kg-K | 280 | |
| 130 |
| Thermal Expansion, µm/m-K | 19 | |
| 8.4 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 84 | |
| 6.2 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 75 | |
| 2.6 |
Otherwise Unclassified Properties
| Density, g/cm3 | 10 | |
| 22 |
Common Calculations
| Stiffness to Weight: Axial, points | 4.6 | |
| 5.7 |
| Stiffness to Weight: Bending, points | 14 | |
| 9.3 |
| Strength to Weight: Axial, points | 9.5 to 21 | |
| 7.1 to 9.3 |
| Strength to Weight: Bending, points | 11 to 18 | |
| 6.9 to 8.3 |
| Thermal Shock Resistance, points | 16 to 34 | |
| 21 to 28 |
Alloy Composition
| Aluminum (Al), % | 0 to 0.0050 | |
| 0 |
| Cadmium (Cd), % | 0 to 0.050 | |
| 0 |
| Copper (Cu), % | 26.6 to 29 | |
| 0 |
| Iridium (Ir), % | 0 | |
| 14.5 to 15.5 |
| Iron (Fe), % | 0 to 0.050 | |
| 0 |
| Lead (Pb), % | 0 to 0.030 | |
| 0 |
| Nickel (Ni), % | 0 to 0.010 | |
| 0 |
| Phosphorus (P), % | 0 to 0.030 | |
| 0 |
| Platinum (Pt), % | 0 | |
| 84.3 to 85.5 |
| Silver (Ag), % | 71 to 73 | |
| 0 |
| Zinc (Zn), % | 0 to 0.060 | |
| 0 |
| Residuals, % | 0 | |
| 0 to 0.2 |