Comparison of the corrosion resistance of an Al–Cu alloy and an Al–Cu–Li alloy

Abstract

In this study, the corrosion mechanisms of the AA2024-T3 and the AA2098-T351 were investigated and compared using various electrochemical techniques in 0.005 mol L −1 NaCl solution. The severe type of corrosion in the AA2098-T351 was intragranular attack (IGA) although trenching and pitting related to the constituent particles were seen. On the other hand, the AA2024-T3 exhibited severe localised corrosion associated with micrometric constituent particles, and its propagation was via grain boundaries leading to intergranular corrosion (IGC). Electrochemical techniques showed that the corrosion reaction in both alloys was controlled by diffusion. The non-uniform current distribution in both alloys showed that EIS was not a proper technique for comparing the corrosion resistance of the alloys. However, local electrochemical techniques were useful for the evaluation of the corrosion resistance of the alloys.

Use of Amperometric and Potentiometric Probes in Scanning Electrochemical Microscopy for the Spatially-Resolved Monitoring of Severe Localized Corrosion Sites on Aluminum Alloy 2098-T351

“…These alloys are reported to have low density, good mechanical strength, and good toughness [ 4 , 5 , 6 ]. Al-Cu-Li alloys, such as 2098, present a reduction in Li content compared to previous first and second generation alloys [ 2 , 7 ], and this reduction causes greater toughness compared to alloys from previous generations [ 5 , 6 ]. This feature represents a significant advantage, since low toughness characteristics were a disadvantage in previous Al-Li alloys.…”

“…This feature represents a significant advantage, since low toughness characteristics were a disadvantage in previous Al-Li alloys. The 2098 Al-Cu-Li alloy has a chemical composition that contains elements such as Cu, Li, Mg, Mn, Zr, Ag and Ti responsible for its advanced microstructure [ 7 , 8 ]. The main phase responsible for the good mechanical properties of Al-Cu-Li alloys is the T1 phase (Al 2 CuLi) [ 2 , 7 , 9 ].…”

“…The 2098 Al-Cu-Li alloy has a chemical composition that contains elements such as Cu, Li, Mg, Mn, Zr, Ag and Ti responsible for its advanced microstructure [ 7 , 8 ]. The main phase responsible for the good mechanical properties of Al-Cu-Li alloys is the T1 phase (Al 2 CuLi) [ 2 , 7 , 9 ]. However, the corrosion mechanism of Al-Cu-Li alloys is related to the T1 phase and micrometric particles enriched with Cu and Fe [ 2 , 3 ].…”

Dissimilar Friction Stir Lap Welding of AA2198 and AA7075 Sheets: Forces, Microstructure and Mechanical Properties

“…Williams and Starke [11] stated that these Al-Li alloys can be considered optimal candidates for aerospace and aircraft vehicles, due to low density, high speci c modulus and speci c strength, the same consideration has been drawn by Goebel et al a latest study considering the latest developments of Al-Li alloys. Yin et al [12] reported that the alloys belonging to the recently developed third generation of damage-tolerant Al-Li alloys, such as AA2198, demonstrated relatively higher mechanical properties, Zhang S. et al [13] stated that these high mechanical properties can be attributable mostly to the precipitation of the T 1 (Al 2 CuLi) phase, whereas Milagre et al [14] proved that the attendance of Li lower density and enhance stiffness. In contrast Xu et al [15] and lately Krug et al [16] reported that the previous generations of Al-Li alloys, e.g.…”

Estudo da corrosão localizada da liga de alumínio 2198-T8 soldada por fricção e mistura

“…Embora toda a amostra tenha sofrido ataque localizado, menor quantidade de produtos de corrosão foi formada sobre a ZM Figura 48 (e) do que sobre o MB Figura 48 (d). Convém ressaltar que, devido à elevada agressividade da solução utilizadaneste ensaio, algumas das características da CLS (tais como: área protegida catodicamente ao redor do centro do pite e anel de produtos de corrosão[9,14,15,108,127]) não foram observadas.…”