Pulse anodizing - an overview

Anodizing is a versatile method used to prevent a metal from corrosion by forming an oxide coating over its surface. Various power supplies such as D.C.,A.C. and A.C. superimposed on D.C. are used in industrial anodizing depending upon the different fields of application. For specific applications, especially for hard anodizing of aluminium containing high copper and silicon, the importance of the pulse current technique has been recognised. This paper reviews the entire history of pulse anodizing of metals such as aluminium, drawbacks of other existing power sources, advancement of pulse power sources and applications of pulse current techniques in various types of anidizing such as general pulse anodizing, pulse hard anodizing and pulse colour anodizin