Plasma parameters in electrospark deposition of silver coatings

Spectroscopic measurements and mathematical simulations are conducted to study the composition and parameters of spark discharge in depositing coatings with silver electrodes using an Élitron-22 generator. The effective temperature and electron concentration are measured at the maximum pulse current. It is shown that the intensity of spectral lines of atoms and ions is proportional to the erosion rates of Ag anode and Ag–C composite anode. Pressure in the plasma channel is calculated taking into account the pinch effect (~1 MPa). It is shown that the temperature of the material in the anode spot reaches the boiling point of Ag under about 1 MPa (~3200–3300 K). A mathematical model is used to study the influence of erosion rate, power, and pressure on the plasma parameters and the intensity of spectral lines of anode materials. The method proposed allows evaluating the efficiency of material transfer in the vapor phase during spark deposition of coatings. A method for quantitative spectral determination of carbon in Ag–C material using the spectral lines of doublecharged ions of Ag and C is developed.