18CHE12 / 18CHE22 MODULE 2 ENGINEERING CHEMISTRY

Corrosion and Metal finishing

Corrosion: Introduction, Electrochemical theory of corrosion, Factors affecting the rate of corrosion: ratio of anodic to cathodic areas, nature of corrosion product, nature of medium -pH, conductivity and temperature. Types of corrosion -Differential metal and differential aeration -pitting and water line). Corrosion control: Anodizing -Anodizing of aluminium, Cathodic protection -sacrificial anode and impressed current methods, Metal coatings -Galvanization

Metal finishing: Introduction, Technological importance. Electroplating: Introduction, principles governing electroplating-Polarization, decomposition potential and overvoltage. Electroplating of chromium (bard and decorative). Electroless plating: Introduction, electroless plating of nickel & copper, distinction between electroplating and electro less plating processes