Whether it is mechanical parts or metal components, the most prominent problem is surface wear or corrosion or both.
Here is a brief introduction to the coating application guide:
1. Wear resistance -- thermal spraying technology is the largest application field at high and low temperature.This kind of coating can be divided into the following types:
(1) adhesion wear or scratch resistance -- two surfaces slide relatively, and adhesion wear or scratch occurs when debris adheres from one surface to the other.The typical special coating is cobalt-based tungsten carbide and nickel-chromium/chromium carbide coating.
(2) abrasive wear -- abrasive wear occurs when a harder surface slides on a softer surface and there is wear between the surfaces.When fibers and silk thread
Abrasive wear also occurs when the surface passes through at high speed.The typical proprietary coatings are cobalt-base nickel-chromium alloy, self-fusion alloy mixed molybdenum and chromium oxide coating.
(3) wear resistance to micro-vibration -- cyclic stress caused by repeated loading and unloading leads to surface cracking and large-area shedding.The typical coating is aluminum oxide/titanium dioxide coating.
(4) cavitation abrasion resistance -- the liquid flow produces mechanical impact on the surface.The typical special coating is aluminum bronze coating.
(5) erosion wear resistance -- erosion wear occurs when particles carried by gas or liquid impact the surface at high speed.Special typical coating is alumina/titanium dioxide, alumina coating.
High temperature resistance and oxidation resistance -- this kind of coating is resistant to chemical or physical decomposition, improving the high temperature performance of parts.This kind of coating can be divided into the following types:
(1) thermal barrier coating -- ACTS as a thermal barrier between parts and high-temperature environment.Typical coatings are zirconia coatings stabilized with yttrium oxide.
(2)high-temperature oxidation resistant coating--protects the substrate against high-temperature oxidation.Typical coatings are nickel/chromium coatings.
(3) heat-resistant corrosion coating -- protects the substrate exposed to heat-corrosive gases.Typical coatings are nickel/chromium coatings.
3, anti-corrosion coating--choose this kind of coating is more complex, because the parts in service, environmental temperature and a variety of media on the coating material have certain requirements, generally use cobalt base alloy, nickel base alloy and oxide ceramics as coating materials, through improving the density of the coating, through the penetration of corrosion media;Reasonable selection of coating materials and parts of the substrate oxidation/reduction potential, to prevent electrochemical corrosion, coating corrosion inhibiting agent.
4. Conductive coating or insulating coating -- this kind of coating can be divided into the following types:
(1) conductive coating -- the special typical coating is copper coating.
(2) insulation coating -- a typical special coating is alumina coating.
(3) shielding coating--the typical coating for anti-electromagnetic interference (EMI) or high-frequency interference (RFI) is copper coating.
Restoration coating - this type of coating is mainly used to repair parts due to wear or machining out of tolerance.The choice of coating material mainly depends on the application requirements of the parts.