Nowadays, friction, lubrication and wear are the three most important research topics in tribology. Friction will cause wear, resulting in the failure effect of mechanical parts, which is generally caused by one of the three factors of wear, corrosion and fatigue, and is closely related to the life and reliability of mechanical parts. Wear can be divided into the following four categories:
(1) Adhesive wear: when the material friction occurs due to its surface irregularity, the whole process is the “point contact” between the micro convex body on the sample surface and the grinding disc. Under the double action of the relative movement and pressure between the sample surface and the grinding disc, there is shear fracture between the adhesion connection points, and there are scratches on the wear surface. When the wear is serious, the material composition will transfer 。
(2) Abrasive wear: the essential reason for this phenomenon is that there are rough particles on the surface of the sample or impurities on the grinding surface, which will cause the friction surface of the sample to be scratched and cause some particles to fall off. This phenomenon often occurs in the blade of vane pump when it works. The main mechanism of abrasive wear is extrusion spalling, furrow and fatigue damage.
(3) Fatigue wear: under alternating stress, when the fatigue strength is exceeded, cracks will appear on the friction surface and extend to fracture spalling. Scaling and pitting are two typical characteristics of fatigue wear, which are common in practical production.
(4) Corrosion and wear: chemical or electrochemical reaction often occurs in the normal environment of metal materials with the medium, and the reaction produces corrosion products. This product has weak adhesion ability and peels off with continuous friction, and then the new metal surface continues to react with the medium. This is a repeated cycle process, and the degree of this kind of wear is low.