ELECTROCHEMICAL STUDY OF THE INTERACTION BETWEEN FATTY-ACID AND OXIDIZED COPPER

Boundary lubrication involving reactions between the metal oxide layer s and adsorbed polar species has been reported by several authors. In this study, the effect of an oxide layer on the mechanism of boundary lubrication during copper wire drawing was examined by electrochemical and surface analysis techniques. The minimum oxide thickness to initi ate chemical and electrochemical reactions, and the oxide growth rate were determined by electrochemical methods. The oxide formed prior to chemical reaction with a fatty acid during boundary lubrication, and t he chemical products were analyzed by electron spectroscopy for chemic al analysis (ESCA) and Auger electron spectroscopy (AES). The properti es of adsorbed layers were characterized by AC impedance spectroscopy. Optimum boundary lubrication can only be achieved during copper defor mation, if the oxide thickness exceeds the minimum thickness of 60 Ang strom and is composed of cuprous oxide. (C) 1997 Elsevier Science Ltd.