PORCELAIN
| PORCELAIN | ||||||
|---|---|---|---|---|---|---|
| GROUP | C. 100 | |||||
| SUB GROUP | 110 | 111 | 120 | 130 | ||
| FEATURE OF COMPOSITION | Al₂O₃ < 30% | Al₂O₃ < 30% | Al₂O₃ 30 - 50% | Al₂O₃ > 50% | ||
| APPLICATION RANGE | L.V. and H.V. insulation, good mechanical properties, suited for small middle and large-sized insulators. | L.V. insulation, small and middle sized insulators, suited for complicated pressed pieces & Resistors and rheostats. | L.V. and H.V. insulation, high mechanical strength, good thermal shock resistance, suited for small, middle and large - sized insulators. | L.V. & H.V. insulation, excellent mechanical and thermal properties, suited for small. Middle and large sized insulators. | ||
| PROPERTIES | ||||||
| COLOUR | White | Special White | White | Grey | White / Grey | |
| POROSITY (Vol. %) | 0 | 0 | 0 | 0 | 0 | |
| BULK DENSITY (g/cm²) | 2.30 | 2.40 | 2.50 | 2.50 | 2.70 | |
| HARDNESS (Mohs Scale) | 7-8 | 7-8 | 7-8 | 7-8 | 7-8 | |
| FLEXURAL STRENGTH (N/mm²) | Unglazed | 60 | 40 | 100 | 100 | 140 |
| Glazed | 70 | 50 | 120 | 120 | 160 | |
| MODULUS OF ELASTICITY (10³ N/mm²) | 60 | - | 80 | 80 | 100 | |
| THERMAL EXPANSION COEFFICIENT (10⁻⁶ K⁻¹) |
a20 - 100°C | 4.15 | 4.15 | 4.90 | 4.90 | 5.60 |
| a20 - 300°C | 4.50 | 3.90 | 4.75 | 4.75 | 5.35 | |
| a20 - 600°C | 4.55 | 4.60 | 5.95 | 5.95 | 6.45 | |
| a20 - 800°C | 5.10 | 4.50 | 5.70 | 5.70 | 6.45 | |
| THERMAL SHOCK RESISTANCE MIN (K) | 150 | 150 | 150 | 150 | 150 | |
| SPECIFIC HEAT CAPACITY (20-100C) | 800-900 | 800-900 | 800-900 | 800-900 | 800-900 | |
| THERMAL CONDUCTIVITY (20-100C) | 2.0 | 2.0 | 2.5 | 2.5 | 2.8 | |
| DIELECTRIC STRENGTH METHOD A (KV/mm) | 20 | - | 20 | 20 | 20 | |
| RELATIVE PERMITTIVITY (48 to 62Hz) | 6.0 | - | 6.5 | 6.5 | 6.5 | |
| DISSIPATION FACTOR AT 20C (10³) | 48-62 Hz | 25 | - | 25 | 25 | 30 |
| 1 KHz | - | - | - | 12 | - | |
| 1 MHz | 12 | - | 12 | - | 15 | |
| VOLUME RESISTIVITY IN TERMS OF TEMPERATUR E (D.C.)cm | 20°C | 10¹³ | 10¹² | 10¹³ | 10¹³ | 10¹³ |
| 200°C | 10⁸ | 10⁸ | 10⁸ | 10⁸ | 10⁸ | |
| 600°C | 10⁴ | 10⁴ | 10⁴ | 10⁴ | 10⁴ | |