Abstract
This work is an attempt to understand the physical mechanisms lying on the basis of using DC torch modulation technology for spraying. The influence of the plasma disturbances created by means of arc current modulation and an influence of these disturbances on thermodynamic parameters and dynamic viscosity of the modulated plasma jet are carried out. Thus, the phenomena providing modulation effects, both as in the plasmatron itself as well as in the mechanisms influencing on the plasma technology parameters have become understandable. It was shown, that inserting hydrocarbons into the air plasma jet conduces to transition of the torch with vortex stabilization of the arc to the laminar spraying mode with a high coefficient use of powder. The obtained physical estimations are used for explanation of the coatings sprayed characteristics. In the article are described shortly the advantages and shortcomings of Plasma Spraying Technology, HVOF, Cold Spraying, Plasma Spraying with Modulation, Detonation Technologies. Each technology has important features like high velocity of spraying particles, melted spraying material and non - melted spraying material. However, these technologies have rigid requirements in regard with a size of spraying powder or wire. In one case it is possible to neglect these requirements (in a certain degree) in the case of Plasma Technology with Modulation which is a combination of all advantages of the above mentioned technologies and was applied to military and space technique.
