How to choose the wear-resistant coating of thermal spraying?
The main purpose of wear-resistant coating on the surface of the mechanical parts is to improve the performance and extend the service life. The basic starting point is to strengthen the surface part, repair the old and utilize the waste and restore the oversize that caused by wear or corrosion to give better wear resistance performance for better quality of products.
The working environment and service conditions are different, also the wear mechanism is different. So selecting the appropriate coating according to our main propose is necessary.
1, Anti abrasion resistance coating
Many mechanical parts such as various crushers, mud pumps, agricultural machinery and concrete mixers and other construction machinery often lose efficacy because of suffering the abrasion that caused by the minerals, rocks, sediment and so on. Spraying some iron-based, nickel and cobalt base material on the surface of this kind of mechanical wear parts or adding WC, Al2O3, Cr2O3, ZrO2 and other ceramic particle composite to these spraying material can significantly improve the abrasive wear resistance.
2, Anti-sticking wear resistance coating
Spraying some iron, nickel, cobalt-based WC, Al2O3, Cr2O3, ZrO2 composite coatings or ceramic on the surface of the component will increase or change the physical, chemical and crystalline structure of the friction, thereby improving the mechanical parts of the anti-sticking wear performance. In addition, the molybdenum coating has excellent resistance to adhesion under boundary lubrication conditions.
3, Fretting wear resistance coating
The cam follower, cylinder liner, turbine blades and other parts are often malfunctioning due to fretting wear. Spraying self-fluxing alloy, metal oxide or carbide ceramics, some nickel and iron cobalt based materials can significantly improve the fretting wear resistance of parts.
4, Heat-resistant coating
All kinds of hot work dies, rolling pipe diameter perforation machine, die-casting mold and powder metallurgy mold and so on, they not only serve under high temperature environment, but also suffer wear, squeeze, impact and hot and cold fatigue. We can spray some cobalt based self-fluxing alloys, Ni/Al and ceramics to improve high temperature wear resistance.
5, Impact wear resistance and cavitation wear coating.
The failure of various fans, water and electrical valves are mainly due to erosion wear. While hydraulic turbine blades, nozzles and different kinds of cylinder liner often fail because of cavitation erosion. These parts can be sprayed with nickel-based self-fluxing alloy, self-fluxing alloy plus copper powder, stainless steel, ultrafine Al2O3, Cr2O3, WC composite powder to significantly improve the ability of erosion resistance and resistance to cavitation wear.
