18K Yellow Gold (Au-12.5Cu-12.5Ag) vs Pure Platinum (Pt 99.95%)
Property comparison of 18K Yellow Gold (Au-12.5Cu-12.5Ag) and Pure Platinum (Pt 99.95%), both precious metal.
| Property | 18K Yellow Gold (Au-12.5Cu-12.5Ag) | Pure Platinum (Pt 99.95%) | Difference |
|---|---|---|---|
| Tensile strength | 300 MPa | 145 MPa | -52% |
| Elastic modulus | 75,000 MPa | 170,000 MPa | +127% |
| Density | 15,500 kg/m³ | 21,450 kg/m³ | +38% |
| Brinell hardness | 80 HB | 60 HB | -25% |
| Thermal conductivity | 320 W/m·K | 72 W/m·K | -78% |
| Specific heat | 200 J/kg·K | 132 J/kg·K | -34% |
| Coefficient of thermal expansion | 0.000014 1/K | 0.000009 1/K | -38% |
| Melting point | 912 °C | 1,769 °C | +94% |
Difference is Pure Platinum (Pt 99.95%) relative to 18K Yellow Gold (Au-12.5Cu-12.5Ag). Values are taken from the representative row of each material; both materials may have multiple heat treatments or conditions on their individual pages.
Identification
- grade
- 18K yellow
- standard
- Smithells Metals Reference Book 8th Ed.
- heat treatment
- annealed
- grade
- commercially pure
- standard
- ESPI Metals technical data / Johnson Matthey PMR 1966
- heat treatment
- annealed 700C
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