Is one of the most important two discoveries: friction has nothing to do with the apparent contact area, friction and function in the "city" meaning friction sliding object. Because of friction law contains a large number of micro and nano scale phenomenon, involving the basis of physics, chemistry, material science and engineering, to clarify the phenomenon has become a fascinating study in applied physics, so today's tribology can be said to be the fashionable edge discipline, this article will be to previous research findings and the status quo of this field are introduced briefly.

Tribology should belong to the source of science and technology

 and can be traced back to 5000 years ago in the neolithic age, in 400 BC, has been applied in the door of the assyrians rural shaft hole of bearing, and on a images of the ancient Egyptian tomb, with the slaves to drag the statue on the plank. Dumping them in front of the statue of a liquid, while the fluid is oil, water, or milk archaeologists have plentiful method validation, but it is the first recorded in the lubricant to reduce friction. Lanzhou university is directly proportional to the positive pressure of the physics department of gansu province in 73000, the ratio is called the coefficient of friction.

Coulomb model now appears to be very appropriate, because in nanometer scale, attachment methods plays a main role.
Mechanism of friction and normal pressure with today's most friction theory assumes that the shear strength (block sliding force per unit area) is constant, the resulting ZENEO bearing friction is proportional to the actual contact area. For microscopic observation showed that the surface of the material is irregular, determine the real contact area is the summation of the contact point, and thus determine the size of the friction force.

ZENEO bearing from the viewpoint of coulomb

As defined by the friction coefficient, friction coefficient of different materials differ slightly, but the different interface, the shear stress can change several orders of magnitude. Steel is more than 40 times Gu, for example, the friction force and the shear strength (Gu low steel high) and the actual contact area (Gu steel small) on both results.
In addition, the micro convex body surface height is gaussian distribution under the condition of process equipment (surface) normally, contact area and the relationship between the load is very close to linear. For some systems, the shear stress along with the increase of load increase, this suggests that there is another mechanism contributes to the friction force. Close contact with metal and metal, for example, contact "cold welding" which can lead to significant adhesion occurs, the phenomenon of deviating from the law of friction can be observed. ZENEO bearing, for polymer system, or more generally on the viscoelastic system, often deviated from the second law of friction phenomenon can be observed. Rubber is one of this kind of material, automobile tires should roll with low loss and high sliding friction.