Inhibition of stress corrosion cracking of alloy AA8090 T-8171 by addition of rare earth salts

摘要

Aluminium-lithium alloys are suitable for aeronautical purposes because of their good mechanical properties and high damage tolerance. Although these alloys are less susceptible to stress corrosion cracking than conventional alloys, Al-Li-Cu-Mg alloy (8090-T8171) still experiences this problem in a NaCl + H2O2 solution. In this work it has been demonstrated that the addition of 10,000 ppm of CeCl3 to the medium inhibits the stress corrosion cracking of 8090 alloy by precipitation of cerium oxides/ hydroxides. The deposition of these compounds on the alloy surface decreases the pit density and slows the crack growth through the grain boundaries by hindering the anodic dissolution of T phases. © 2004 Elsevier Ltd. All rights reserved.