Why use reasonable arc power?

       Arc power is an important process parameter for plasma spraying.



      Under the premise of the type of working gas used, the flow rate and the amount of powder feeding, when the arc power is greater than the optimum value, the temperature of the plasma flame is very high, and more gas will be converted into plasma. This may vaporize some of the spray material and cause changes in coating composition. Coagulation of spray material vapors between the substrate and the coating or between layers of coatings can cause poor adhesion. Excessive arc power can also increase the ablation of the nozzle and electrode.

      If the arc power is too low, a partially ionized gas and a plasma flame with a lower temperature will be obtained, which will cause insufficient heating of the sprayed particles, and the bonding strength, hardness and deposition efficiency of the coating will be low.

      When the flow rate of the main gas (argon) is 0.5m3/min and the flow rate of the secondary gas (hydrogen) is 0.0075m3/min, the current is increased from 700A to 800A, and the nozzle life is reduced by 30%.

      When other conditions are constant, the arc power has a certain effect on the coating density.