Establishing a correlation between interfacial microstructures and corrosion initiation sites in Al/Cu joints by SEM–EDS and AFM–SKPFM

Sarvghad, Madjid; Parvizi, Reza; Davoodi, Ali; Haddad-Sabzevar, M.; Imani, Amin

doi:10.1016/j.corsci.2013.10.039

Cited by 76 publications

(28 citation statements)

References 46 publications

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“…Although FSW is a very promising welding technique presently under regular industrial use, there are only a few electrochemical studies using local techniques concerning its influence on the local corrosion behaviour of welded Al alloys as atomic force microscopy (AFM) and scanning Kelvin probe force microscopy (SKPFM) for Al/Cu lap joint [16] and scanning electrochemical microscopy (SECM) and local electrochemical impedance spectroscopy (LEIS) for AA2050-AA7449 butt weld [17]. However, to our knowledge, there is no report in the literature of using SVET to elucidate the involved corrosion mechanisms of FSW joints.…”

Section: Introductionmentioning

confidence: 99%

Corrosion study of the friction stir lap joint of AA7050-T76511 on AA2024-T3 using the scanning vibrating electrode technique

2015

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Section: Introductionmentioning

confidence: 99%

Corrosion study of the friction stir lap joint of AA7050-T76511 on AA2024-T3 using the scanning vibrating electrode technique

2015

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“…z E-mail: yjin@ustb.edu.cn; jinshanp@kth.se difference between phases. 17,18 Recently this approach has been increasingly used in corrosion studies of various alloys. [19][20][21][22] However, due to variations in the experimental conditions, such as sample surface preparations prior to SKPFM measurements, there is lack of reproducibility of reported Volta potential data measured by different research groups.…”

mentioning

confidence: 99%

First-Principle Calculation of Volta Potential of Intermetallic Particles in Aluminum Alloys and Practical Implications

Jin

Liu

Zhang

et al. 2017

J. Electrochem. Soc.

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This work presents a theoretical assessment of galvanic (relative) nobility of four intermetallic particles (IMPs), Al 2 Cu, Al 2 CuMg, Mg 2 Si and MgZn 2 , in aluminum alloys through work function calculation based on density functional theory (DFT). The concepts of work function, Volta potential and relative nobility are discussed with respect to the IMPs and aluminum matrix. The calculated Volta potentials are compared with reported experimental Volta potentials measured by scanning Kelvin probe force microscopy (SKPFM). Various crystal faces and terminal types are examined in the DFT calculation, showing that these two factors have a significant effect on the work function value. Considering the large divergence in the reported experimental data, the comparison shows a general agreement between the calculated and experimental Volta potential data for the investigated IMPs. The DFT calculations provide theoretical explanations for several experimental phenomena. The results demonstrate that DFT calculation is a valuable theoretical approach for assessment of the relative nobility of different phases in the alloys, providing complementary information to experimental data from SKFPM. Moreover, the implications of the calculated Volta potentials are discussed with respect to the corrosion potentials. The addition of various alloying elements into the aluminum (Al) matrix to improve mechanical performance of Al alloys may simultaneously increase their susceptibility to localized corrosion. This is mainly due formation of intermetallic particles (IMPs) that may trigger micro-galvanic corrosion along the interface between the IMPs and the alloy matrix.1 The potential differences between the IMPs and the matrix may result in localized dissolution of the matrix or dealloying of the IMP. 2The most common IMPs present in 2xxx and 7xxx series Al alloys include Al 2 CuMg (S-phase), Al 2 Cu (θ-phase), Al 7 Cu 2 Fe (β-phase), MgZn 2 (η-phase) and Mg 2 Si.3-5 IMPs containing Cu and Fe, such as Al 2 Cu. 6 and Al 7 Cu 2 Fe, 7 are considered to be cathodic with respect to the matrix, acting as local cathodes and thus promoting cathodic reactions such as oxygen reduction. In contrast, Mg-rich IMPs, such as Al 2 CuMg, are considered anodic relative to the matrix, resulting in selective dissolution and concomitant Cu-enrichment of the IMP.8 These localized corrosion events may eventually trigger other corrosion forms, such as stress corrosion cracking or intergranular corrosion.9 Therefore, micro-galvanic corrosion effects between IMPs and the Al matrix is considered to be of utmost importance for the overall service performance of Al alloys.In 1987, Stratmann started to use the Kelvin probe to investigate corrosion properties of metals under thin electrolyte films.10 His measurements revealed a linear relationship between Volta potential and corrosion potential of Cu, Zn, Fe and other metals. Later, the scanning Kelvin microprobe was developed and used for Volta potential measurements of several metals in humid atmospheres.11 Du...

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“…In some cases, however, a notable difference in thermal conductivity has a beneficial effect on the joint: for example, no heat-affected zones were produced in a study using friction stir welding, due to the high sink rate resulting from the high thermal conductivity of Cu (Sarvghad-Moghaddam, et al, 2014).…”

Section: Influence Of Physical Propertiesmentioning

confidence: 99%

“…Different tool configurations vary the frictional heating effects thereby influencing the mode of deformation in metal (Mubiayi and Akinlabi, 2013). For instance, Sarvghad-Moghaddam, et al (2014) showed the dominant impact of the tool on the properties and microstructure in the weld by varying the tool shoulder and pin. Galvão et al (2010; who experimented on friction stir welding using scrolled and conical friction stir tools showed that the tool has immense influence on the production of successful welded joints.…”

Section: Influence Of Welding Parametersmentioning

confidence: 99%

Factors influencing Al-Cu weld properties by intermetallic compound formation

Kah

Vimalraj

Martikainen

et al. 2015

Int J Mech Mater Eng

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Dissimilar welding of aluminium (Al) and copper (Cu) has many applications in the electric power, electronic and piping industries. The weldments in these applications are highly valued for their corrosion resistance, heat and electricity conducting properties. The Al-Cu joints are lighter, cheaper and have conductivity equal to that of copper alloys. Much research has investigated dissimilar welding of Al-Cu by solid-state welding and fusion welding processes with the aim of optimising the properties and strength of such dissimilar joints. The main aim of the study is to critically review the factors influencing the properties of the Al-Cu joint. The study mainly discusses about the effects of intermetallic compounds (IMC) on the properties of Al-Cu joint and their effect while in service. The effects of joining aluminium alloy 1060 with pure copper by laser welding, friction stir welding and brazing have been reviewed and compared. The review shows that the various intermetallic compound formations in the joint have both beneficial and detrimental effects. The characteristics of these intermetallic compounds vary according to the location of the phase formed. Comparison of processes and parameters for welding of Al 1060 with pure Cu shows that the formation of the intermetallic compounds and their effects on the weld properties are mainly influenced by the welding speed, heat input, the thermal properties of the base metals and the filler metal as well as the dilution between the base metal and filler metal.

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Establishing a correlation between interfacial microstructures and corrosion initiation sites in Al/Cu joints by SEM–EDS and AFM–SKPFM

Cited by 76 publications

References 46 publications

Corrosion study of the friction stir lap joint of AA7050-T76511 on AA2024-T3 using the scanning vibrating electrode technique

Corrosion study of the friction stir lap joint of AA7050-T76511 on AA2024-T3 using the scanning vibrating electrode technique

First-Principle Calculation of Volta Potential of Intermetallic Particles in Aluminum Alloys and Practical Implications

Factors influencing Al-Cu weld properties by intermetallic compound formation

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