85-platinum 15-iridium vs. ASTM B596 Au-Cu
Both 85-platinum 15-iridium and ASTM B596 Au-Cu are otherwise unclassified metals.
For each property being compared, the top bar is 85-platinum 15-iridium and the bottom bar is ASTM B596 Au-Cu.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 220 | |
| 100 | 
| Elongation at Break, % | 5.5 to 34 | |
| 4.3 to 17 | 
| Poisson's Ratio | 0.38 | |
| 0.41 | 
| Shear Modulus, GPa | 81 | |
| 36 | 
| Shear Strength, MPa | 370 to 420 | |
| 280 to 360 | 
| Tensile Strength: Ultimate (UTS), MPa | 560 to 730 | |
| 450 to 620 | 
Thermal Properties
| Latent Heat of Fusion, J/g | 110 | |
| 77 | 
| Melting Completion (Liquidus), °C | 1820 | |
| 1060 | 
| Melting Onset (Solidus), °C | 1790 | |
| 930 | 
| Specific Heat Capacity, J/kg-K | 130 | |
| 150 | 
| Thermal Expansion, µm/m-K | 8.4 | |
| 14 | 
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 6.2 | |
| 14 | 
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.6 | |
| 6.7 | 
Otherwise Unclassified Properties
| Density, g/cm3 | 22 | |
| 18 | 
Common Calculations
| Stiffness to Weight: Axial, points | 5.7 | |
| 3.1 | 
| Stiffness to Weight: Bending, points | 9.3 | |
| 8.5 | 
| Strength to Weight: Axial, points | 7.1 to 9.3 | |
| 6.8 to 9.4 | 
| Strength to Weight: Bending, points | 6.9 to 8.3 | |
| 7.1 to 8.8 | 
| Thermal Shock Resistance, points | 21 to 28 | |
| 22 to 30 | 
Alloy Composition
| Copper (Cu), % | 0 | |
| 9.0 to 11 | 
| Gold (Au), % | 0 | |
| 89 to 91 | 
| Iridium (Ir), % | 14.5 to 15.5 | |
| 0 | 
| Platinum (Pt), % | 84.3 to 85.5 | |
| 0 | 
| Residuals, % | 0 | |
| 0 to 0.4 |