Experimental Study of the Evolution of Acid Fronts During Galvanic Corrosion of the CS/AA6063 and CS/AA7075 Systems

Abstract

This work proposes an experimental arrangement to determine the propagation of pH fronts during the galvanic corrosion process of different aluminum alloys in contact with carbon steel and under gelled-electrolytes. Both thick and thin electrolyte thickness were tested as well as concentrated and dilute electrolytes. The results show that the propagation of acidic fronts is faster under dilute electrolytes. Under thin electrolytes the evolution of the acid front is confined around the metallic joint of the system (always on top of the aluminum alloy). Such a behavior is not observed when the galvanic couple is under thick electrolytes.