Advantages of graphite
1. Low surface wettability: Graphite will not be wetted by most molten metals.
2. High temperature resistance: Graphite will not melt and sublimate at 3900K. It can be stabilized in 750K air.
3. High temperature shock resistance: Graphite is especially resistant to heat shock. Therefore, short-term heating and cooling are not a problem.
4. Specific heat: There is little difference in specific heat among different graphite grades.
5. Good mechanical strength: Compared with other materials, the tensile strength, compressive strength and flexural strength of graphite increase with the increase of temperature before it reaches 2700 C.
6. Machining speed is fast: Graphite has good machinability and can form complex and high precision parts. Cutting resistance is 1/4 of that of copper, and processing energy is twice that of copper.
7. Density: 1.6-1.9g/cm3 is equivalent to 1/4 of iron or 1/5 of copper. It can be used for large electrodes.
8. The speed of electro-etching is 1.5-3 times as fast as that of copper, and rough beating is more advantageous.
9. Low electrode consumption: 1/3-1/5 of copper according to different electrical conditions.
10. High thermal conductivity: Graphite has more thermal conductivity than many metals, which decreases with the increase of temperature and varies with the degree of graphitization.
11. Small thermal expansion