Abstract
Cu coatings were obtained by the VLPPS (Very Low Pressure Plasma Spray) process using a torch F4-VB. The tank pressure was varied from 1 mbar to 5 mbar: these specific conditions can allow obtaining a higher vapor condensation fraction in the coating. Different sizes of powders are used to compare the vaporization level. The other possible influencing factors for obtaining compact film-like coating are also considered such as the distance between the torch and substrate, the orientation of the vapors and also the substrate temperatures. Microstructures of coatings are analyzed and combined with the results of plasma diagnostics. Jobin-Yvon spectrometer (type TRIAX190, UK) and Plasus Specline Spectroscopy software are both used for detecting and analyzing plasma spectrum data. The value of plasma electronic excited temperature Te was calculated through choosing Hα and Hβ two atom spectra. The results showed that the plasma belongs to cold plasma in the local thermodynamic equilibrium situation in VLPPS.
