What are the characteristics of argon as a plasma working gas?

       1) Argon gas (Ar) is a monatomic gas, which does not decompose during the heating thermal ionization process, but directly absorbs heat for ionization. The temperature rises quickly.



     2) Although the enthalpy value of argon is not as good as that of nitrogen, argon is an inert gas. It does not chemically react with various metals, nor does it dissolve in various metals, and has good protective properties. Therefore, argon can be used when spraying powders with strong chemical activity (such as WC, Al) and when the quality of the coating is high.

     3) Argon gas has a relatively high density and high viscosity. When using argon gas for spraying, the arc is relatively stable.

     4) The arc voltage of pure argon plasma arc is relatively low, the thermal conductivity is relatively small, and the arc ignition performance is better than that of diatomic gas. Therefore, in plasma spraying, it is more appropriate to use argon to start the arc, and argon and hydrogen should be mixed.

     5) The source of argon is difficult, expensive, and limited in application. Therefore, in general, nitrogen should be used as much as possible, especially in the maintenance of construction machinery.