Principle and application of plasma spraying

What’s plasma spraying?

In the high temperature surface process technology, when some gas (such as Nitrogen, argon, hydrogen, helium and so on) produces plasma thought compressive arc, The energy of the plasma arc concentrated temperature is very high, its flame flow temperature above ten thousand degrees Celsius, it can melt all solid engineering material. This is plasma spraying.

In plasma spraying process, the material to be deposited— typically as a powder, sometimes as a liquid, suspension or wire — is introduced into the plasma jet, emanating from a plasma torch. In the jet, where the temperature is on the order of 10,000 K, the material is melted and propelled towards a substrate.

Applications:

Surface of Traction equipment

The roll surface

Most classical thermal spraying

This technique is mostly used to produce coatings on structural materials. Such coatings provide protection against high temperatures (for example thermal barrier coatings for exhaust heat management), corrosion, erosion, wear; they can also change the appearance, electrical or tribological properties of the surface, replace worn material, etc.

It can also be used for spray powder processing (spheroidization, homogenization, modification of chemistry, etc.).This technique with variation may also be used to create porous structures, suitable for bone ingrowth, as a coating for medical implants.

The initial parameters of plasma system should be carefully set, then the spraying gun can run continuously for several hours under standard condition. Plasma spraying is better than arc or oxygen flame spraying with lower oxygen content and porosity.