Output carbon materials have porous structure – pores cover 10%–30% of volume. They are filled with impregnants, such as:
– synthetic resins
– metals- e.g., antimony
Beside a structure sealing function, impregnants improve strength properties, abrasion resistance. Simultaneously, impregnants determine application temperature, therefore, non-impregnated plastics of increased graphite content are used for work in high temperatures.
Due to physical properties of carbon-graphite plastics, one can distinguish:
– hard carbon-graphite materials
– electrographites
PHYSICAL PROPERTIES OF CARBON-GRAPHITE PLASTICS USED BY “CERTECH”
| Properties | Carbon-graphite plastics | ||
| Impregnated with resin | Impregnated with antimony | Without impregnation | |
| Density [g/cm3] | 1.82 | 2.25 | 1.68 |
| Hardness | 110 HRB | 115 HRB | 95 HRB |
| Bending strength [Mpa] | 75 | 95 | 35 |
| Compressive strength [Mpa] | 200 | 260 | 100 |
| Young’s modulus E [GPa] | 27 | 30 | 9 |
| Coefficient of thermal linear expansion α [10-6/K] | 5.0 | 4.0 | 3.7 |
| Thermal conductivity coeff. λ [W/mK] | 14 | 20 | 25 |
| Thermal shock resistance [°C] | 200 | 250 | 250 |
| Temperature resistance in oxidizing atmosphere [°C] | 200 | 400 | 500 |
| Temperature resistance in reducing atmosphere [°C] | 200 | 550 | 2500 |