Corrosion and Stress Corrosion of Aluminum–Lithium Alloys

Holroyd, N.J.H.; Scamans, G. M.; Newman, R.C.

doi:10.1016/b978-0-12-401698-9.00014-8

Cited by 21 publications

(13 citation statements)

References 67 publications

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“…Previous studies showed that Al-based alloys are passive in halide-free aqueous electrolytes with pH values between 4.0 and 8.5. 29,30 In this pH range, the Al-based alloys generally form a passive stable Al 2 O 3 layer. The oxide film is self-healing and any mechanical abrasion or damage of the surface film does not lead to the corrosion of the underlying alloy.…”

Section: Introductionmentioning

confidence: 99%

Tribological and corrosion properties of Al–12Si produced by selective laser melting

et al. 2014

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The effect of annealing on the tribological and corrosion properties of Al-12Si samples produced by selective laser melting (SLM) is evaluated via sliding and fretting wear tests and weight loss experiments and compared to the corresponding material processed by conventional casting. Sliding wear shows that the as-prepared SLM material has the least wear rate compared to the cast and heat-treated SLM samples with abrasive wear as the major wear mechanism along with oxidation. Similar trend has also been observed for the fretting wear experiments, where the as-prepared SLM sample displays the minimum wear loss. On the other hand, the acidic corrosion behavior of the as-prepared SLM material as well as of the cast samples is similar and the corrosion rate is accelerated by increasing the heat treatment temperature. This behavior is due to the microstructural changes induced by the heat treatment, where the continuous network of Si characterizing the as-prepared SLM sample transforms to isolated Si particles in the heat-treated SLM specimens. This shows that both the wear and corrosion behaviors are strongly associated with the change in microstructure of the SLM samples due to the heat-treatment process, where the size of the hard Si particles increases, and their density decreases with increasing annealing temperature.

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Section: Introductionmentioning

confidence: 99%

Tribological and corrosion properties of Al–12Si produced by selective laser melting

et al. 2014

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“…Research has determined that the effects of heat treatment, grain size, grain boundary segregation and precipitates, hydrogen embrittlement, as well as the loading mode, all have an influence on the SCC resistance of aluminum alloys [5][6][7]. Various studies have also shown that the stress corrosion cracking behavior of aluminum alloys in chloride environments is largely dependent on the specific immersion conditions [18,19,[44][45][46]. Additionally, precipitates can cause areas of localized corrosion because of differences in corrosion potential as compared with surrounding areas, resulting in hydrogen evolution, promoting SCC [7][8][9][10]17,[48][49].…”

Section: Stress Corrosion Crackingmentioning

confidence: 99%

“…Dealloying is associated with stress corrosion cracking in aluminum alloys, steels, and noble metal alloys such as AgAu and CuAu [14][15][16]. Renner et al [17] noted that cracks can form in CuAu alloys during local dealloying and depend on the crystallographic orientation of the substrate material and stability of applied inhibitor layers.Higher strength alloys such as the 7xxx and the 2xxx alloys are more susceptible to SCC [18][19][20][21][22] due to the high alloying additions. The 6xxx series alloys are usually not as susceptible to SCC when exposed to high tensile stresses and highly corrosive atmospheres [18,[21][22][23].…”

mentioning

confidence: 99%

“…For the most part, the service record of 6xxx alloys shows no reported cases of SCC. But in accelerated laboratory tests where high stresses and aggressive solutions are used, cracking has been observed [18,23]. These results were predominately demonstrated in alloys with high alloy content and containing silicon in excess of the Mg 2 Si ratio and/or high percentages of copper [23].…”

mentioning

confidence: 99%

“…Higher strength alloys such as the 7xxx and the 2xxx alloys are more susceptible to SCC [18][19][20][21][22] due to the high alloying additions. The 6xxx series alloys are usually not as susceptible to SCC when exposed to high tensile stresses and highly corrosive atmospheres [18,[21][22][23]. For the most part, the service record of 6xxx alloys shows no reported cases of SCC.…”

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confidence: 99%

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Stress Corrosion Cracking Resistance of Cold-Sprayed Al 6061 Deposits Using a Newly Developed Test Fixture

et al. 2019

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The stress corrosion cracking (SCC) response of Al 6061 bulk deposits produced by high-pressure cold spray (HPCS) was investigated and compared to commercial wrought Al 6061-T6 material. Representative tensile coupons were stressed to 25%, 65% and 85% of their respective yield strength and exposed to ASTM B117 salt fog for 90 days. After exposure, the samples were mechanically tested to failure, and subsequently investigated for stress corrosion cracking via optical and scanning electron microscopy with energy-dispersive X-ray spectroscopy (EDS). The results were compared to the wrought Al 6061-T6 properties and correlated with the observed microstructures. Wrought samples showed the initiation of stress corrosion cracking, while the cold-sprayed deposits appeared to be unaffected or affected by general corrosion only. Optical microscopy revealed evidence of stress corrosion cracking in the form of intergranular corrosion in the wrought samples, while no significant corrosion was observed in the cold-sprayed deposits. Fractography revealed wrought samples failed due to multiple mechanisms, with predominant cleavage and intergranular failure, but cold-sprayed samples only failed by ductile dimple rupture. The difference in SCC response between the differently processed materials is attributed to the documented benefits of the cold spray process, which includes maintaining fine grain structure of the feedstock powder and high density after consolidation, low oxidation, and work hardening effect.the strength required. The cold spray process can also produce near-net shapes before machining to final components, making it a possible method for three-dimensional (3D) manufacturing. Unlike thermal spray methods or conventional manufacturing processes, the main advantages of using cold spray is that it can produce coatings and bulk materials with no recrystallization, thus maintaining the structure and size of starting powders. As a low-temperature process, it operates below the melting point of metals and results in very low porosity deposits without the need for combustible gasses. Additional motivation to use this process is the low oxide content, which can improve corrosion resistance, mechanical properties, and wear resistance by eliminating sites for localized corrosion and premature failure.There has been a great deal of research into corrosion mechanisms in metallic materials over the past century [5][6][7][8][9][10][11][12][13][14][15][16][17]. Atmospheric or environmentally assisted corrosion is one of the least understood areas of corrosion. Stress corrosion cracking is a type of atmospheric corrosion that is very difficult to detect and mitigate, since it only occurs in alloys that have been under stress in corrosive environments. Metallic materials used extensively in engineering and defense applications are susceptible to corrosion. Corrosion costs the US billions of dollars per year in preventative maintenance and product loss. There are many different types of corrosion that can attack metallic materials,...

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The effect of creep aging on localized corrosion resistance of AA2060 alloy

Wang

Zhan

Liu

et al. 2019

Materials & Corrosion

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The influence of creep aging at varied stresses on the localized corrosion behavior of AA2060 has been studied in this paper. Samples were subjected to stress free aging (SFA) and creep aging (CA) under two stress levels, after which tensile tests and intergranular corrosion (IGC) tests were carried out. The corrosion morphology and depth were examined using optical microscope. Compared with SFA, CA can enhance the mechanical properties and increase the IGC resistance of Al–Cu–Li alloy but high‐stress CA would intensify the intragranular corrosion penetration in the first 25 hr of aging time. The microstructure observation results show that dislocations introduced by CA provide favorable nucleation sites for T1 precipitates in the grain and impede the growth of T1 precipitates at grain boundary. Therefore, the potential difference between the grain interior and grain boundary can be reduced compared to that for the SFA. The mechanism by which CA affects the corrosion resistance of Al–Cu–Li alloys, as is essential to understand and optimize the creep aging process, has been proposed by considering the effect of creep‐deformation‐induced dislocations.

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Corrosion and Stress Corrosion of Aluminum–Lithium Alloys

Cited by 21 publications

References 67 publications

Tribological and corrosion properties of Al–12Si produced by selective laser melting

Tribological and corrosion properties of Al–12Si produced by selective laser melting

Stress Corrosion Cracking Resistance of Cold-Sprayed Al 6061 Deposits Using a Newly Developed Test Fixture

The effect of creep aging on localized corrosion resistance of AA2060 alloy

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