%0 Journal Article %A Hrabovsky, Milan %A Kopecky, Vladimir %A Chumak, O. %A Kavka, T. %A Maslani, A. %A Sember, V. %A Konrad, M. %A Ctibor, P. %D 2009 %I Begell House %K Plasma torch, dc arc, plasma jet, fluctuations, plasma spraying %N 2 %P 229-240 %R 10.1615/HighTempMatProc.v13.i2.110 %T EFFECT OF FLUCTUATIONS OF DC CURRENT ON PROPERTIES OF PLASMA JET GENERATED IN PLASMA SPRAYING TORCH WITH GERDIEN ARC %U https://www.dl.begellhouse.com/journals/57d172397126f956,4e2a92412d8c6bb5,3ee43dd250915a6a.html %V 13 %X Two different power supplies used for dc arc plasma spraying unit with water stabilized plasma torch were compared - classical thyristor controlled unit with the frequency of the current ripple 300 Hz and the rectifier with the high frequency converter and frequency of the current modulation 30 kHz. For the both types of power supply the arc characteristics were measured, time averaged plasma jet properties were determined from spectroscopic measurements and plasma jet fluctuations were analysed on the basis of diagnostics with an array of high frequency photodiodes. The properties of coatings sprayed with the two power supplies were compared. While time averaged profiles of plasma jet were the same for the both power supplies, the fluctuations of plasma jet differed substantially. Also the dynamic arc voltage characteristics of the arc were different and could be described by modified Cassie equation. The differences of properties of TiO coatings deposited with the use of the two power supplies were not significant. %8 2009-09-01