Ova doktorska disertacija bavi se proučavanjem fenomena Plazma Elektrolitičke Oksidacije (PEO) ventilnih metala (Al, Mg, Ti, Та) i oksidnih slojeva koji se dobijaju u elektrolitima koji sadrže volfram, pre svega u 12-volframsilicijumskoj kiselini. Primenom metoda optičke emisione spektroskopije i analize procesa u realnom vremenu, omogućeno je određivanje: temperature, elektronske gustine plazme, dimenzionalne distribucije i aktivne površine mikro pražnjenja. Pokazano je da PEO procesi na svim ispitivanim metalima pokazuju tendenciju da se broj mikro pražnjenja smanjuje sa vremenom, a da površine poprečnih preseka mikro pražnjenja rastu. Sa porastom vremena PEO procesa broj kanala za pražnjenje se smanjuje, dok njihov dijametar raste i dolazi do povećanja hrapavosti oksidnih površina. Procenat aktivne površine istovremeno izložen događajima mikro pražnjenja takođe raste u početku PEO procesa, dostiže svoj maksimum, a potom polako opada. Sve spektralne linije detektovane u optičko emisionim spektrima u toku PEO procesa pripadaju ventilnim metalima i jonskim i atomskim elementima prisutnim u elektrolitu. Pored jasno izraženih atomskih i jonskih linija, u optičko emisionom spektru dobijenom tokom PEO procesa na magnezijumu, jasno je vidljiva i vibraciona traka MgO molekula, koja odgovara elektronskom prelazu sa pobuđenog B1Σ+ nivoa na osnovni elektronski nivo X1Σ+. Na sličan način, u spektru dobijenom tokom PEO procesa na aluminijumu opaža se jaka vibraciona traka AlO sistema, koja odgovara elektronskom prelazu sa pobuđenog B2Σ+ nivoa na osnovni elektronski nivo X2Σ+. U slučaju PEO procesa na aluminijumu i magnezijumu, koristeći spektroskopske podatke dobijene za AlO, OH i MgO trake, uz primenu kvantno-mehaničkih proračuna, određene su temperature plazme. Iz vibracionih traka MgO molekula procenjeno je da su temperature plazme (11000 ± 2000) K, dok su u slučaju podataka iz OH trake dobijene nešto niže vrednosti temperature (3500 ± 500) K. Iz analiza vibracione trake AlO molekula u slučaju PEO procesa u limunskoj kiselini procenjena temperatura je (8000 ± 2000) K... This doctoral dissertation is focused on investigation of a relatively new, highvoltage anodization process, called Plasma Electrolytic Oxidation (PEO) on valve metals (such as Al, Mg, Ti and Ta) and their oxide coatings obtained in tungsten containing heteropoly acids. Very useful data concerning temperature, dimensional distribution of the microdischarges, their spatial density, and electron density were obtained using optical emission spectroscopy and real time imaging of PEO events. It is shown that the size of microdischarges becomes larger while their number decreases with increased time of PEO. Spatial density of microdischarges is the highest in the early stage of the PEO process and then slowly decreases. The percentage of oxide coatings’ area simultaneously covered by active discharge sites decreases slowly with extended PEO time. All atomic and ionic lines detected in optical emission spectra originate either from electrolyte or from the metal substrate. During the PEO process on magnesium, wide transition band was also recorded corresponding to the v′−v″=0 band sequence of the B1Σ+ – X1Σ+ emission transition of MgO. During the PEO process on aluminum, visible band of B2Σ+ - X2Σ+ emission of AlO system was also detected. By applying spectroscopic, quantum-chemical and thermodynamical methods to analyze spectra in the range of those bands it was possible to determine the temperature of the microdischarges. In the case of PEO process on magnesium, calculated temperatures are about 11000 K ± 2000 K, while analysis of OH bands in the same sysstem yields sligtly lower value of 3500 K ± 500 K. Analysis of AlO band system gave temperature of 8000 K ± 2000 K. The analysis of hydrogen Balmer Hβ line shape in the case of PEO of tantalum and titanium, indicates the presence of two types of discharges during PEO process and the electron number densities of Ne ≈ 0.8×1015 cm−3 and Ne ≈ 2.1×1016 cm−3 are determined. These two electronic concentrations are similar to those obtained during the PEO process on aluminum...