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All crucibles, alumina, magnesia and zirconia to name a few, are manufactured in Capital's own modern purpose-built facility in the Czech Republic where we press, cast and fire various materials into crucibles.
Capital Refractories is able to supply a full range of isostatically pressed crucibles from 2 kg capacity to 75 kg, in different grades and qualities. We use a state-of-the-art semi-automated cold isostatic press. Cold isostatic pressing applies pressure to the workpiece in all directions producing products of uniform density.
The advantages of Isostatically Pressed Crucibles are:
Crucibles are produced by vibration casting (vibrocast) when the required size or shape is uneconomical or impractical by the isopressing production method.
Capital Refractories can offer a range of vibration cast crucibles, including T-Pot Ladles:
Benefits
Complex shapes, e.g. internal pouring siphon
To complement our range of crucibles we also offer numerous ancillary products and materials used within the investment and related foundry industries.
| Quality | Description |
| Alumina... | General purpose crucible. Used for wide range of alloys. |
| .....AL97I | Superior erosion resistance |
| .....AL88I | Improved thermal shock resistance |
| Magnesia... | High resistance to basic slags and titanium alloys. Used in vacuum melting of Ni, Co and Fe based alloys |
| .....MG88I | Used in vacuum melting of Ni, Co and Fe based alloys |
| .....MG95I | Resistant to the special alloys used in semi-conductor and sputter target industries |
| Zirconia | High resistance to acid slags. Wide use in vacuummelting of superalloys. |
| .....ZC93I | .....General applications. |
| .....ZC95I | .....High thermal shock resistance. |
| .....ZC96I | .....Fine grained structure. |
| Quality | Al2O3 | SiO2 | MgO | CaO | Fe2O3 | ZrO2 + HfO2 |
| Alumina AL97I | 97.5 | 1.6 | - | 0.1 | <0.1 | - |
| Alumina AL88I | 88.5 | 9.4 | - | 0.1 | 0.2 | - |
| Magnesia MG88I | 3.5 | 3.8 | 88.0 | 3.8 | 0.2 | - |
| Magnesia MG95I | 0.5 | 0.8 | 95.0 | 2.5 | 0.1 | - |
| Zirconia ZC93I | 0.8 | 1.2 | - | 4.0 | 0.1 | 93.0 |
| Zirconia ZC95I | 1.0 | 1.5 | - | 3.8 | <0.1 | 92.9 |
| Zirconia ZC96I | 0.6 | 0.9 | - | 4.4 | 0.1 | 94.0 |
| Quality | Bulk Density / g cm-3 | Apparent Porosity / % | Thermal Expansion / MK-1 | Thermal Conductivity / W m-1 K-1 | Maximum Service Temperature / °C |
| Alumina AL97I | 2.95 | 23.8 | 8.0 | 4.2 | 1700 |
| Alumina AL88I | 2.59 | 23.8 | 8.0 | 4.2 | 1700 |
| Magnesia MG88I | 2.83 | 17.0 | 14.5 | 2.4 | 1700 |
| Magnesia MG95I | 2.95 | 15.0 | 13.0 | 2.5 | 1750 |
| Zirconia ZC93I | 4.35 | 20.0 | 8.4 | 1.5 | 1850 |
| Zirconia ZC95I | 4.50 | 18.5 | 8.5 | 1.6 | 1850 |
| Zirconia ZC96I | 4.50 | 18.5 | 8.5 | 1.6 | 1850 |
