Effect of equal-channel angular pressing on pitting corrosion resistance of anodized aluminum-copper alloy

Corrosion of Ultrafine Grained Materials by Severe Plastic Deformation, an Overview

“…Indeed, Cu-depleted zone in the vicinity of grain boundaries become much smaller 87) or disappeared in UFG Al-Cu alloys, 150) and this may lead to higher resistance to intergranular corrosion of Cu-Al alloy systems. 75,150) In passivated materials such as aluminum alloy, the passive lm may be different in its stability 151) or even absent 152) on second phase. Therefore, the distribution of the precipitation strongly affect the resistance to pitting corrosion, and in some cases, its impact is stronger than grain size.…”

“…Corrosion behavior has been investigated on UFG materials fabricated mainly by processing of SPD such as ECAP, ARB, HPT for aluminum and its alloy, [87][88][89][90][91][92][93]120,121,143,[150][151][152][153]156,[158][159][160][161][162][163][164][165][166][167][168][169][170][171] magnesium and its alloy, 34,72,[115][116][117]122,123,154,157,[172][173][174][175][176][177][178][179] copper and its alloy, 6,[96][97][98]…”

“…Eizadjouet et al 93) attributed lower corrosion resistance to re nement of Al 3 Fe, Al 6 Fe intermetallics and related defective passive lms. Pitting corrosion resistance of aluminum alloys with precipitation or the second phase (type D) is mostly improved by SPD, 45,75,87,92,120,121,143,[150][151][152][153]156,158,167) , and this improvement is mainly due to physical breakup of the second phase or precipitation which differs in dissolution potential from the matrix and causes defective structure of passive lm. For example, pitting occurs at the interface between the matrix and nobler second phase.…”

Effect of grain size changes on corrosion behavior of copper produced by accumulative roll bonding process

“…The corrosion behavior of the nanostructured copper produced bythe SPD methodsgained only limited attention. Up to now, the works in this field about copper material were restricted to the corrosion behavior of ECAPed copper with and without heat treatment in different solution [14][15][16] . The ARB method for producing the nano structured sheets is a new process in comparison with the ECAP process which the product of the ARB process can be easily used in the fabrication of heat transferring pipes and other equipment that needs sheets with better physical and mechanical properties [17][18][19][20][21] .…”

“…There was not any work on the corrosion behavior of the ARBed copper in the different situation up to now. The investigation of this behavior in the ECAPed copper as the SPD method willberationalbecause in both process sever plastic deformation occurs and the new nanomicrostructure produced [14][15][16] . Vinogradov et al 22 have first reported the anodic polarization behaviour of UFG copper fabricated by Equal-channel angular pressing (ECAP) in modified Livingstonetchant, and concluded that the anodic current in UFG copperis higher in both active and passive regions than that of coarsegrained (CG) counterparts.…”