Characteristics of Graphite as a Lubricant

Low friction, in the range 0.05-0.15 Maximum PV about 0.7MN/ms when dry Good adhesion 

Usable at low temperatures and to 540°C in air Good performance in presence of liquids Good thermal and electrical conductivity 

Poor performance in vacuum or when very dry Black, and therefore unacceptable for certain processes Very complex and variable materials 

Graphite is also more limited by temperature and environment. It only gives low friction in the presence of moisture or certain other contaminants, and this is discussed in more detail later. As a result, without special treatment, its use in air is limited to temperatures below 160 or above 350 C and to pressures above about 350 mbars, (35 kPa). Finally, the load-carrying capacity of graphite is significantly lower than that of molybdenum disulphide. 

The bonding between carbon atoms within a layer consists of strong covalent chemical (electronic) bonds, and this provides the high structural strength. The bonding between layers was originally assumed to consist only of weak van der 

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