Investigation of the Emission Spectra of Electrolytic Plasma During the Synthesis of Oxide-Ceramic Coatings on D16 and AD33 Alloys

Abstract

We study the emission spectra of electrolytic plasmas in the course of synthesis of oxide-ceramic coatings on AD33 and D16 aluminum alloys. By the measuring the degree of broadening of the hydrogen line Hα, we establish the density of electrons in the plasma (5.2–5.7)·1016 cm–3. The temperature of electrons is found according to the relative intensity of emission of aluminum atoms (Al I 3082.15 A, Al I 3092.7 A, Al I 3944.8 A, and Al I 3961.5 A) and ions (Al II 3586.9 A) and is equal to (6.9–7.6)·103 °K. It is shown that, after 7 min of synthesis of an oxide-ceramic coating on D16 alloy, the spectrum contains most sensitive emission lines Cu I 3247.54 A and Cu I 3273.95 A. For this time, we observe the formation of an oxide-ceramic coating with a thickness of 5–10 μm. Most likely, at this distance, the discharge channels act upon the maximal number of intermetallic inclusions, and the copper content of the plasma attains its maximal value.