The relative movement of the two friction surfaces due to mechanical or chemical action of the material from damage to the phenomenon called wear and tear on the surface of what happened. Typically, the mechanical parts to overcome the resistance during the relative movement, bound to wear. Mainly in changing the geometry of the mechanical parts of the original size and shape, with the gap increasing and so on.
Mechanical parts wear a variety of forms, and it is located lubrication, friction in the form of the mechanical properties of the material itself and so on, can be summed up in five general wear and tear in the form of:
1, normal wear and tear: the friction pay in a fluid lubrication, substantially no metal contact with each other directly, its grain diameter is very small, is 100 ~ 10000A0 "
2, adhesive wear: friction surface film did not rupture, the local metal direct contact, instant high temperature, or even individual bond point occurs, wear dramatic increase. For example: gluing gear grazed belong to such wear.
3, abrasive wear: friction between its surface into the grain or dust, equivalent to adding between the metal surface grinding track, so wear faster. These grains may be mixed from the outer dielectric friction surface or internal lubricant, it may be worn sports pay by product, it may be another piece of the material itself hard spot or cast brought grit.
4, fatigue wear: metal surface microcracks sequestration under cyclic stress and the "wedge" effect, and gradually expand, causing wear and, eventually, fatigue spalling, such as: is this form of pitting and wear;
5, corrosive wear: soft and porous metal surface oxidation becomes easy to fall off and lose abrasion resistance. Metal processing micro-channel, content is good, worthy of attention.