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Several new types of thermal spray method

Feb 22, 2017

1. detonation spraying
Detonation gun spraying is the use of oxygen and combustible gases resulting from the combustion of gases expand and explode, releasing heat and shock wave, pulse gas explosion of energy and shock wave will be spraying powder heating, bombarded by accelerated to form a coating on the surface of the workpiece.
Explosion spray coating combining high strength, can be more than 70 MPa, dense coating (<2 porosity), low surface temperature, up to 200 ℃; coating evenly, easy control of the thickness, coating thickness of 0.025 mm-0.3 mm, surface roughness can be smaller than Rn1.6 m, RaO.025 m can be achieved after grinding. But high prices for equipment, high noise, must be conducted in the sound.
2. electro-thermal explosion spraying
Electro-thermal explosion spraying metal conductor (wire, foil or powder) along the axial moment DC high voltage is applied, 106-1O7 A/cm2 current on a metal internal explosion, shock waves from the metal particles at very high speed into the substrate and substrate cooling sharply, thus forming coating. Electrothermal explosion spray coating and substrate can be achieved by metallurgical combine to increase the bond strength.
3. ultrasonic flame spraying
Supersonic flame spray of principle for: fuel gas and combustion agent to must of proportion import combustion chamber within mixed, produced explosion type burning, high temperature gas by combustion chamber upper burning head within of 4 root tilt nozzle into copper nozzle, powder by sent powder gas (Ar, and N2) quantitative along burning head within carbide tungsten Center casing sent people high temperature gas in the, by high temperature high-speed gas with out nozzle, directly spray in artifacts Shang formed coating. Supersonic flame spraying has velocity of particles at low temperature, high, dense coating, high bonding strength and spraying high efficiency.
4. supersonic arc spraying
Supersonic arc spraying machine consists of power supply, supersonic spray gun, wire feed unit, control box and the compressed air system, etc. It made two melting metal or alloy electrodes by electric motors, variable speed drive, intersects the spray guns have caused short circuit arc, melting, and hurled by compressed air spray particles to the pretreated workpiece surface coating. Laval nozzle Lance structure when compressed air after Laval nozzle air speed can be significantly increased, and atomization particles to achieve supersonic spray coating. Supersonic arc spraying with long service life, low production cost, high efficiency.
5. supersonic plasma spraying
This technique has the characteristics of high temperature and high speed, especially of oxides and ceramic coating of carbide, cermet coating with coating density, low porosity, high strength characteristics.
6. cold spray
Cold spray, also known as cold air dynamic spraying method, using preheated compressed gas (normally at 100-7OO c) solid particles (5um-50um) up to 300-1500/s, the powder particles in a completely solid under high velocity impact matrix, resulting in large plastic deformation and deposition to the base surface coating. Cold spray coating at low temperature, spray particles high deposition rate, low porosity, the equipment is relatively simple and coated to withstand stress and so on.