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.Electrospark deposition of silver coatings is an efficient method to create electric contacts. This method ensures good adhesion and thus produces coatings with needed thickness and saves precious metals [1]. Electromigration in the deposition of coatings (in particular, silver coatings) was examined earlier in detail in [2−4]. These studies deal with the structure and composition of coatings, their dependence on the composition of electrodes, and impact of equipment parameters on electromigration. However, to gain a deep insight into the material transfer, more detailed spectroscopic and theoretical studies of the processes that occur in the discharge plasma are needed.Experiments using an Élitron-22M apparatus have shown that carbon introduced into the electrodes promotes faster electrospark transfer of electrode material to the surface of the contact part [5]. The study demonstrates that even a thin layer of graphite deposited on the cathode increases the transfer coefficient. When this apparatus is used, the products of erosion of the copper anode are known to consist of approximately equal parts of vapor and liquid phases [6]; therefore, we employed the spectroscopic method to ascertain the role of transfer in the vapor phase. This method analyzes the intensity of spectral lines to show how metal vapor concentration changes in the discharge plasma.

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543.51 Phosphorus and trace impurities in aluminum phosphate powders and coatings are identified with glowdischarge mass spectrometry (GDMS), atom emission spectrometry (AES), x-ray fluorescence (XRF), and chemical analysis. Alumina powders with particles 60 to 40 μm in size that are covered with Al(PO 3 ) 3 and AlPO 4 with TiO 2 additives are sprayed using a supersonic air plasmatron. The distribution of elements across the coating on a steel substrate is examined with GDMS. The effect of polyatomic clusters is taken into account in determining Mg, P, S, and Ti by mathematical simulation. Phosphorus is identified with AES in a dc air arc controlled to produce similar conditions for exciting PI lines in the evaporation of test and reference (Ca 3 (PO 4 ) 2 ) samples. Comparing the results obtained by different methods shows that x-ray fluorescence reveals the concentration from the surface of nucleus-shell particles. Measurements show that some part of phosphorus is lost in spraying because orthophosphates transform into metaphosphates.Plasma-deposited gas-dynamic coatings based on aluminum phosphates have high oxidation and wear resistance and, therefore, can be used in the chemical industry and in units as drawing dies and drums. When particles go through the discharge plasma, their phase and elemental compositions change. High pressures and temperatures, which also modify the surface layer, develop in contact with supersonic particles. Of interest is to develop techniques for elemental analysis of such coatings, including nondestructive examination.Given the powder treatment and coating technology, we can state the analytical task clearer. Powder consisting of aluminum phosphate mixed with alumina powder containing titanium oxide additives (so-called microabrasive powder [1]) was used for coating.The mixture was dried, rubbed through sieve, annealed at 850 to 900°C, and ground in a ball mill to obtain particles 60 to 40 µm in size. Following the thermal treatment, a layer that consists of Al(PO 3 ) 3 and AlPO 4 and has a well-developed surface (Fig. 1) is formed on the alumina particles. The powder was sprayed using a Kiev-S supersonic air plasmatron. In spraying, particles fuse and liberate P 2 O 5 , and a layer consisting of Al 2 O 3 and AlPO 4 is formed on the surface. With this technology, the substrate surface is coated with heterophase particles that have Al 2 O 3 as the nucleus

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