Development of Al-Mg-Li alloys for marine applications

Kramer, Lawrence S.; Langan, Timothy; Pickens, J. R.

doi:10.1007/bf00366863

Cited by 19 publications

(3 citation statements)

References 4 publications

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“…Therefore, these alloys are ideal materials for the aerospace and aeronautical industry, since the economic benefits are significant, such as increased payload and better fuel efficiency [5]. Furthermore, the potential Al-Li alloys exhibit in marine industry is significant [6,7].…”

Section: Introductionmentioning

confidence: 99%

“…A complex precipitation sequence has been observed during the aging process of Al-Cu-Li alloy systems. The precipitation sequence impacts the interaction mechanism between dislocations and precipitates during plastic deformation, consequently influencing the mechanical properties of the aged alloys [7,15]. Several precipitates have been observed through aging, including GP zones, θ'(Al 2 Cu), β'(Al 3 Zr), T 1 (Al 2 CuLi), δ'(Al 3 Li) and S'(Al 2 CuMg) [2,4,15,16].…”

Section: Introductionmentioning

confidence: 99%

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Experimental and Computational Study of Microhardness Evolution in the HAZ for Al–Cu–Li Alloys

Maritsa,

Deligiannis,

Tsakiridis

et al. 2024

Crystals

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The Laser Beam Welding (LBW) of aluminum alloys has attracted significant interest from industrial sectors, including the shipbuilding, automotive and aeronautics industries, as it expects to contribute to significant cost reduction associated with the production of high-quality welds. To comprehend the behavior of welded structures in regard to their damage tolerance, the application of fracture mechanics serves as the instrumental tool. However, the methods employed overlook the changes in the microstructure within the Heat-Affected Zone (HAZ), which leads to the degradation of the mechanical properties of the material. The purpose of this study is to simulate microhardness evolution in the HAZ of AA2198-T351 LBW. The material represents the latest generation of Al-Cu-Li alloys, which exhibit improved mechanical properties, enhanced damage tolerance behavior, lower density and better corrosion and fatigue crack growth resistance than conventional Al-Cu alloys. In this work, the microhardness profile of LBW AA2198 was measured, and subsequently, through isothermal heat treatments on samples, the microhardness values of the HAZ were replicated. The conditions of the heat treatments (T, t) were selected in line with the thermal cycles that each area of the HAZ experienced during welding. ThermoCalc and DICTRA were employed in order to identify the strengthening precipitates and their evolution (dissolution and coarsening) during the weld thermal cycle. The microstructure of the heat-treated samples was studied employing LOM and TEM, and the strengthening precipitates and their characteristics (volume fraction and size) were defined and correlated to the calculations and the experimental conditions employed during welding. The main conclusion of this study is that it is feasible to imitate the microstructure evolution within the HAZ through the implementation of isothermal heat treatments. This implies that it is possible to fabricate samples for fatigue crack growth tests, enabling the experimental examination of the damage tolerance behavior in welded structures.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Experimental and Computational Study of Microhardness Evolution in the HAZ for Al–Cu–Li Alloys

Maritsa,

Deligiannis,

Tsakiridis

et al. 2024

Crystals

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“…At present, Al−Mg−Li alloys are widely used in aircraft [ 16 ] and ship building [ 17 ] due to a combination of high specific strength, good corrosion resistance, and weldability. Alloying with zirconium or scandium increases the precipitation hardening and the recrystallization temperature (thermal stability) of ternary alloys.…”

Section: Introductionmentioning

confidence: 99%

Thermal Stability and S‐Phase Evolution in Ultrafine‐Grained Al−Mg−Li Alloy Produced by Equal‐Channel Angular Pressing

2021

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Ultrafine‐grained (UFG) aluminum alloys produced by severe plastic deformation demonstrate high mechanical properties but low thermal stability, which can negatively affect their service characteristics. Herein, the thermal stability of structure and S‐phase (Al2LiMg) evolution in UFG Al−5.5Mg−2.2Li−0.12Zr alloy produced by equal‐channel angular pressing (ECAP) are studied during heating and direct annealing. It is found that the UFG structure with an average grain size of about 1 μm formed by ECAP is preserved at up to 410 °C (≈0.7 T m), with a significant decrease in dislocation density (from 5 × 109 to 3 × 108 cm−2) and the fraction of low‐angle grain boundaries (from 20% to 5%) at 380 °C. The dissolution of metastable semicoherent SI‐phase particles located within grains at 330 °C is accompanied by a corresponding increase in Mg content in solid solution. The transfer of Mg atoms from solid solution to grain boundaries at 380 °C with subsequent coalescent growth of SII particles leads to an increase in the volume fraction (from 3% to 12%) and size of the particles and to recrystallization in UFG Al−Mg−Li alloy at 415 °C.

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Microstructural Evolution and Mechanical Properties of Cast Al–2.6Li–2.8Mg–(0.5, 1.4)Cu–0.2Zr–0.2Sc Alloys during Heat Treatment

Zha,

Wang,

et al. 2024

Adv Eng Mater

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Cu is commonly used to improve the mechanical properties of Al–Li alloys, but its exact role in multicomponent Al–Li alloys is not fully understood. Herein, the microstructure and mechanical properties of two cast Al–2.6Li–2.8Mg–(0.5, 1.4)Cu–0.2Zr–0.2Sc (wt%) alloys aged at 165 °C are compared. The results show that Alloy 1.4Cu possesses finer grain size and better mechanical properties than Alloy 0.5Cu. The δ′ (Al3Li), Al3(Sc, Zr, Li) phases, and Guinier–Preston–Bagaryatsky zones are formed in both alloys. During the early stage of ageing (8 h), many dispersed S′ (Al2CuMg) phases precipitate only in Alloy 1.4Cu and coarsen continuously. Instead, many rod‐shaped S1 (Al2MgLi) phases start to precipitate in Alloy 0.5Cu up to ageing for 32 h and then coarsen continuously with ageing. Moreover, Alloy 1.4Cu shows narrower δ′‐precipitate‐free zones along grain boundaries than Alloy 0.5Cu. The higher strength and ductility with more uniform strain distribution for Alloy 1.4Cu than Alloy 0.5Cu is attributed to finer grain size and unique phase formation for the former.

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Development of Al-Mg-Li alloys for marine applications

Cited by 19 publications

References 4 publications

Experimental and Computational Study of Microhardness Evolution in the HAZ for Al–Cu–Li Alloys

Experimental and Computational Study of Microhardness Evolution in the HAZ for Al–Cu–Li Alloys

Thermal Stability and S‐Phase Evolution in Ultrafine‐Grained Al−Mg−Li Alloy Produced by Equal‐Channel Angular Pressing

Microstructural Evolution and Mechanical Properties of Cast Al–2.6Li–2.8Mg–(0.5, 1.4)Cu–0.2Zr–0.2Sc Alloys during Heat Treatment

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