The common types and characteristics of mechanical wear in machining mainly include the following:
Running in wear, hard particle wear, surface fatigue wear, thermal wear, phase change wear and hydrodynamic wear are introduced in detail below.
1. Running in wear: this kind of wear is the wear that occurs when the machine is processed under normal load, speed and lubrication conditions. The development process of this kind of wear is generally slow, and it will not have a great impact on the processing quality in the short term.
2. Hard particle wear: this kind of wear is mainly due to the abrasive particles falling from the part itself or the hard particles entering the machine tool from the outside, which enter the processing area of the workpiece and are damaged by mechanical cutting or grinding. This kind of wear has a serious impact on the processing quality.
3. Surface fatigue wear: this kind of wear is mainly caused by micro cracks or pitting pits under the action of mechanical alternating load, resulting in damage to parts. This kind of wear usually has a certain relationship with pressure, load characteristics, machine material, size and other factors.
4. Hot wear: this kind of wear is the heat generated in the friction process of the parts acting on the parts, causing the parts to temper, soften, burn, wrinkle and other phenomena. This kind of wear usually occurs in high-speed and high-pressure sliding friction, which is relatively destructive and accompanied by accidental wear.
5. Corrosive wear: as a kind of chemical action, corrosive wear refers to the wear of parts caused by chemical erosion or the combination of part surface and oxygen to produce hard and brittle metal oxides that are easy to fall off when the part surface is in contact with acid, alkali, salt liquid or harmful gas.
6. Phase change wear: this kind of wear is the wear of parts caused by the long-term work of parts under high temperature, the heating of metal structure grains on the surface of parts, the oxidation around the grain boundary, and the generation of small gaps, which makes the parts fragile and reduces the wear resistance.
7. Hydrodynamic wear: this kind of wear is caused by the impact of liquid or particles mixed in liquid on the surface of parts at a faster flow rate.