High Stability, High Enthalpy APS Process Based on Combined Wall and Gas Stabilizations of Plasma (Part 1. Process Introduction)

The paper describes the major concept of a recently developed high voltage – low current APS process and torch that is based on combined wall and gas stabilizations of plasma (C⁺Plasma).  It is shown that C⁺Plasma process is capable to efficiently generate stable plasmas without drifting or pulsing. Plasma gas selection presently includes N₂, N₂-H₂, N₂ -Ar-H₂(He), etc. Additionally, C⁺Plasma offers a decoupling option that allows to separately control plasma enthalpy and velocity. Availability of N₂-H₂ plasmas with a high enthalpy within 30-70 kJ/g range, presently not achievable by other commercial processes, allows for a new level of APS efficiency and capability.  Presented data includes illustrations of the C⁺Plasma’s durability and stability as well as information regarding the process capability and extended plasma enthalpy/velocity operating window. The data shows that the C⁺Plasma process may satisfy the growing industrial requirements dealing with cost reduction efforts and development of advanced coatings.