Abstract
Ceramic-like coatings formed by Plasma Electrolytic Oxidation (PEO) functionalize surfaces improving the mechanical, thermal, and corrosion properties of various nonferrous and ferrous alloys. This chapter provides the state-of-the-art of PEO for Al, Mg, Ti, Zr alloys, and steels including general knowledge, such as process parameters, common microstructure and properties, and detailed information for each material such as electrical characteristics, electrolytes, commercial processes, and applications. The chapter concludes with a summary of the current trends and future outlook for PEO coatings.