Why Are Electrodes Made From Graphite?
Graphite is extremely soft and a good lubricant. It also has a high melting point and can be made into a variety of shapes. The material is also a great conductor of electricity and heat, as it can withstand very high temperatures. Graphite is the only non-metal that can conduct electricity. It is able to do so because of the delocalisation of valence electrons in the carbon layers (a phenomenon called aromaticity). This allows them to move freely around the electrode. It is this ability to conduct electricity that allows an electrode to be used for electrical discharge machining, which is where our business specialises in.
Electrodes are made from graphite because of its special properties. It is very resistant to thermal shock, has a low CTE for geometrical stability, and can be machined at high currents and speeds. It is also a very light material (five times lighter than copper) and does not wear as rapidly, making it ideal for long-term use.
It can withstand extremely high temperatures and is used to form a mould for steel, which is then melted in giant buckets called ladles. Graphite is the only material that can withstand the intense heat of this process.
Approximately 1/3 of the world’s steel is produced using electric arc furnaces. Graphite electrodes are vital to this process, which produces more recycled steel than any other method. China is the largest graphite exporting country, producing 75-80% of the global supply.
