NANOTRIBOLOGY APPLICATION IN THE COINING INDUSTRY III - THERMOHYDRODYNAMIC MODEL
When one chemical molecule, such as an oxygen, contacts with one surface atom, there are only two states. Either the molecule reacts with the atom to form a new substance, or they adhered together by the Van de Waals force without a reaction. The two states possibility issue can be solved by a binomial equation. The more chances the molecules meet the surface atoms, the higher the rate they may react. The reaction rate depends on how many chances an absorbed molecule contact with the solid surface atoms. In thermodynamics, this chance is called accessible states. And the values of the accessible states is defined as entropy of the contact system. It is clear that the entropy of a moving system is larger than the fixed system, even without a mathematics deduction. When the thickness of a lubrication film is reduced to nano level, this reaction rate must be considered.