Behavior of intergranular corrosion of ⟨011⟩ tilt grain boundaries of pure copper bicrystals

It is believed that grain boundaries are preferentially attacked in aqueous corrosive environment resulting in the formation of intergranular corrosion groove. Following to the previous paper which reported the formation of intergranular ''ridge'' formed in pure copper bicrystals in modified Livingston's etchant, we further examined the formation condition of the ridge as a function of misorientation angle of grain boundary. It was shown that there exist a critical misorientation angle which decides ridge or groove, and the formation of the ridge appears to be independent of grain boundary structure and energy. Both the intergranular grooves and ridges consist of planar Facets close to {0 0 1} plane. The formation of the intergranular ridge is discussed in terms of electrochemical polarization and the dissolution anisotropy. (C) 2002 Elsevier Science Ltd. All rights reserved.