Materials
Ceramic materials are inorganic materials, mainly manufactured from natural raw materials. The major components of polyphase materials are clay, kaolin, feldspar and soapstone. Additional components could be used, as alumina and zircon to achieve special properties e.g. high strength.
We manufacture a wide palette of various materials, among them also highly-specialized ceramic materials with excellent mechanical, electrical and thermal properties.
Furthermore, for any specific request from the customer, we develop suitable material out of standard requests.
Our ceramic materials are classified into group of materials in accordance to standard IEC 60 672.
Porcelain
Porcelain materials are alumina or quartz based silicate materials, which are classified according to standard IEC 60 672 in group C 100 – alkaline alumina-silicate porcelains. Porcelain has excellent insulation properties, even at high temperature range, it is basically used in electro technical applications.
Typical characteristics:
- high mechanical strength
- excellent electrical insulation properties
- good resistance to chemicals
- high dielectric strength
- corrosion resistant
- chemical inertness
ETI manufacture the following porcelains:
- C110: quartz porcelain, shaped with extrusion and slip casting technology
- C111: quartz porcelain, shaped with wet pressing technology
- C 120: alumina porcelain, with high mechanical strength, shaped with extrusion and slip casting technology
- C 130: high alumina porcelain, with high mechanical strength, shaped with extrusion technology.
Steatite
Steatite is a ceramic material based on natural raw materials and it consists mainly of soapstone. According to standard IEC 60 672 it is classified in group C – 200 – magnesium silicate. It is mainly used as insulating material for electric engineering. Regarding to specific usage demands, the composition could be modified with zirconium addition.
Typical characteristics:
- high mechanical strength
- excellent electrical insulation properties
- low dielectric loss factor in high frequency range
- high dielectric strength at room and high temperatures
ETI manufacture the following steatites:
- C 220: alkaline steatite, shaped with dry pressing and extrusion technology
- C 221: non alkaline steatite, shaped with dry pressing, extrusion and injection moulding technology
- C 230: porous steatite, shaped with dry pressing and extrusion technology. Typical properties are: high porosity, low thermal conductivity and high electric resistance at high temperature
Cordierite
Cordierite materials are insulating materials, according to standard IEC 60 672 classified in group C 400 – alkaline earth alumina silicates and C 500 – porous alumina silicates.
Typical characteristics:
- high thermal shock resistance
- high temperature resistance
- low coefficient of thermal expansion
- high specific resistance at high temperatures
ETI manufacture the following cordierites:
- C 410: nonporous cordierite material, shaped with dry pressing and extrusion technology
- C 510: porous cordierite material, shaped with dry pressing, extrusion and slip casting
- C 520: porous cordierite material, shaped with dry pressing, extrusion and slip casting
- C 530: porous cordierite for higher temperature applications, shaped with dry pressing, extrusion and slip casting
Mullite ceramics
Mullite ceramics is insulating material, according to standard IEC 60 672 classified in group C 600 – materials based on alumina-silicates (mullite ceramics).
Typical characteristics:
- high mechanical strength
- good electrical insulation properties
- corrosion resistant
- chemical inertness
ETI manufacture the following mullites:
- C 610: alumina porcelain, with high mechanical strength, shaped with extrusion and dry pressing technology.
Al2O3 ceramics
Alumina oxide (Al2O3) is one of the most important technical oxide ceramic materials. It has wide range of applications. According to standard IEC 60 672 it is classified in group C 700 – high-alumina ceramics.
Typical characteristics:
- high mechanical strength and hardness
- high thermal conductivity
- good electrical insulation at high temperatures
- corrosion resistance
ETI manufacture the following alumina oxide materials:
- C 786: 86 – 95% Al2O3, shaped with extrusion and dry pressing
- C 795: 95 – 99% Al2O3, shaped with extrusion, dry pressing, slip casting and injection moulding
- C 799: > 99% Al2O3, shaped with extrusion and dry pressing technology
| Materials IEC 60672-3 |
C 110 | C 111 | C 120 | C 130 | C 221 | C 230 | C 410 | C 520 | C 530 | C 610 | C 786 | C 795 | C 799 |
| Open porosity (Vol. %), max. |
0 | 3 | 0 | 0 | 0 | 35 | 0,5 | 20 | 30 | 0 | 0 | 0 | 0 |
| Bulk density (Mg/m3), min. |
2,2 | 2,2 | 2,3 | 2,5 | 2,7 | 1,8 | 2,1 | 1,9 | 2,1 | 2,6 | 3,4 | 3,5 | 3,7 |
| Flexural strength, unglazed (MPa), min. |
50 | 40 | 90 | 140 | 30 | 60 | 30 | 30 | 30 | 120 | 250 | 280 | 300 |
| Flexural strength, glazed (MPa), min. |
60 | - | 110 | 160 | - | - | - | - | - | - | - | - | - |
| Coefficient of linear thermal expansion 30o - 600oC (10-6 K-1) |
4-7 | 4-7 | 4-7 | 5-7 | 7-9 | ? | 2-4 | 2-4 | 4-6 | 5-7 | 6-8 | 6-8 | 7-8 |
| Thermal conductivity 30o - 100oC (W/mK) |
1-2,5 | 1-2,5 | 1,2-2,6 | 1,5-4 | 2-3 | 1,5-2 | 1,2-2,5 | 1,3-1,8 | 1,4-2 | 2-6 | 14-24 | 16-28 | 19-30 |
| Resistance to thermal shock T (oC), min. |
150 | 150 | 150 | 150 | 100 | - | 250 | 300 | 350 | 150 | 140 | 140 | 150 |
| Dissipation factor at 20oC, 48Hz - 60Hz (10-3), max. |
25 | - | 25 | 30 | 1,5 | - | 25 | - | - | - | 0,5 | 0,5 | 0,2 |
| Relative permittivity 48Hz - 62Hz |
6-7 | - | 6-7 | 6-7,5 | 6 | - | 5 | - | - | 8 | 9 | 9 | 9 |
| Temperature of use T (oC), max. |
- | - | - | - | 1200 | 1000 | 1200 | 1200 | 1200 | 1200 | 1400 | 1400-1500 | 1400-1700 |
| Materials IEC 60672-3 |
| C 110 | C 111 | C 120 | C 130 | C 221 | C 230 | C 410 | C 520 | C 530 | C 610 | C 786 | C 795 | C 799 |
| Open porosity (Vol. %), max. |
| 0 | 3 | 0 | 0 | 0 | 35 | 0,5 | 20 | 30 | 0 | 0 | 0 | 0 |
| Bulk density (Mg/m3), min. |
| 2,2 | 2,2 | 2,3 | 2,5 | 2,7 | 1,8 | 2,1 | 1,9 | 2,1 | 2,6 | 3,4 | 3,5 | 3,7 |
| Flexural strength, unglazed (MPa), min. |
| 50 | 40 | 90 | 140 | 30 | 60 | 30 | 30 | 30 | 120 | 250 | 280 | 300 |
| Flexural strength, glazed (MPa), min. |
| 60 | - | 110 | 160 | - | - | - | - | - | - | - | - | - |
| Coefficient of linear thermal expansion 30o - 600oC (10-6 K-1) |
| 4-7 | 4-7 | 4-7 | 5-7 | 7-9 | ? | 2-4 | 2-4 | 4-6 | 5-7 | 6-8 | 6-8 | 7-8 |
| Thermal conductivity 30o - 100oC (W/mK) |
| 1-2,5 | 1-2,5 | 1,2-2,6 | 1,5-4 | 2-3 | 1,5-2 | 1,2-2,5 | 1,3-1,8 | 1,4-2 | 2-6 | 14-24 | 16-28 | 19-30 |
| Resistance to thermal shock T (oC), min. |
| 150 | 150 | 150 | 150 | 100 | - | 250 | 300 | 350 | 150 | 140 | 140 | 150 |
| Dissipation factor at 20oC, 48Hz - 60Hz (10-3), max. |
| 25 | - | 25 | 30 | 1,5 | - | 25 | - | - | - | 0,5 | 0,5 | 0,2 |
| Relative permittivity 48Hz - 62Hz |
| 6-7 | - | 6-7 | 6-7,5 | 6 | - | 5 | - | - | 8 | 9 | 9 | 9 |
| Temperature of use T (oC), max. |
| - | - | - | - | 1200 | 1000 | 1200 | 1200 | 1200 | 1200 | 1400 | 1400-1500 | 1400-1700 |
