The performances of magnesium alloys remain insufficient to further enhance the application potential of ultralight magnesium alloys.In this work,a Mg-8Li-3Y-2Zn alloy was prepared through vacuum melting and subsequent...The performances of magnesium alloys remain insufficient to further enhance the application potential of ultralight magnesium alloys.In this work,a Mg-8Li-3Y-2Zn alloy was prepared through vacuum melting and subsequent heat treatment at 300,450,and 500°C.The material properties of the resulting samples were assessed through microstructural observation,tensile testing,electrical conductivity measurements,and electromagnetic shielding effectiveness(EMI-SE)testing.The influence of the Mg-8Li-3Y-2Zn alloy microstructure on its mechanical and electromagnetic shielding properties in different states was investigated.It was found that the as-cast alloy containsα-Mg,β-Li,Mg_(3)Zn_(3)Y_(2),and Mg_(12)ZnY phases.Following heat treatment at 500℃(HT500),the blockα-Mg phase transformedfine needle-shapes,its tensile strength increased to 263.7 MPa,and its elongation reached 45.3%.The mechanical properties of the alloy were significantly improved by the synergistic effects imparted by the needle-shapedα-Mg phase,solid solution strengthening,and precipitation strengthening.The addition of Y and Zn improved the EMI-SE of Mg-8Li-1Zn alloy,wherein the HT500 sample exhibits the highest SE,maintaining a value of 106.7–76.9 dB in the frequency range of 30–4500 MHz;this performance has rarely been reported for electromagnetically shielded alloys.This effect was mainly attributed to the multiple reflections of electromagnetic waves caused by the severe impedance mismatch of the abundant phase boundaries,which were in turn provided by the dual-phase(α/β)and secondary phases.Furthermore,the presence of nano-precipitation was also believed to enhance the absorption of electromagnetic waves.展开更多
In this work,a novel surface strengthening strategy for Mg-Li alloys was proposed,called cold spraying assisted high-speed laser cladding.CuAl9 aluminum bronze coating was firstly deposited on Mg-Li alloy by cold spra...In this work,a novel surface strengthening strategy for Mg-Li alloys was proposed,called cold spraying assisted high-speed laser cladding.CuAl9 aluminum bronze coating was firstly deposited on Mg-Li alloy by cold spraying,and then CoCrFe_(0.5)Ni_(1.5)Mo_(0.1)Nb_(0.68)eutectic highentropy alloy(EHEA)coating was prepared on the CuAl9 coating utilizing high-speed laser cladding.A gradient coating consisted of in-situ transition region and EHEA layer formed by bidirectional diffusion.The in-situ transition region was composed ofβ-Li,Cu_(2)Mg and Cu_(3)Al_(2)phases.TEM analysis indicated that Cu_(2)Mg and Cu_(3)Al_(2)phases were well matched with theβ-Li matrix phase.The EHEA coating had a nano-lamellar eutectic microstructure with relatively small lamellar-spacing(<100 nm).Metallurgical bonding interfaces formed between the EHEA coating,transition region and Mg-Li substrate.The evolution mechanism of the coating was revealed from the perspectives of mixing enthalpy,atomic radius difference and laser energy distribution.In 3.5 wt.%NaCl solution,the corrosion potential of the EHEA coating(-24 m VSHE)was 1345 m VSHEhigher than that of Mg-Li alloy(-1369 m VSHE),while the corrosion current density of the EHEA coating(3.13×10^(-7)A·cm^(-2))was almost three orders of magnitude lower than that of Mg-Li alloy(1.25×10^(-4)A·cm^(-2)).The wear rate of Mg-Li alloy(1.11×10^(-3)mm^(3)/N·m)was about 36 times higher than that of the EHEA coating(3.05×10^(-5)mm^(3)/N·m).展开更多
The process of room temperature rolling is a straightforward and efficient method for producing high strength Mg-Li alloys,but the underlying strengthening mechanism remains unclear.In this study,we successfully enhan...The process of room temperature rolling is a straightforward and efficient method for producing high strength Mg-Li alloys,but the underlying strengthening mechanism remains unclear.In this study,we successfully enhanced the tensile properties of a novel dual-phase MgLi alloy through room temperature rolling,with a remarkable yield strength of 201 MPa and an elongation-to-failure of 14%.Microhardness testing was conducted to evaluate the contribution of the Mg-and Li-phases to the improvement in strength.The results demonstrate that the hardness of Mg-phase reaches 60 HV,which is significantly higher than the 49 HV observed in Li-phase,indicating that the Mg-phase after rolling plays a pivotal role in enhancing material strength.The presence of a high density of dislocations stored in the Mg-phase emerges as the dominant factor contributing to improved strength in Mg-Li alloys.In-situ compression testing reveals thatslip activation and twinning-induced slip serve as internal mechanisms for continuous deformation and hardening within the Mg-phase.Despite numerous precipitated Mg-phase particles within the Li-phase matrix,the hardness analysis reveals minimal strain-induced phase transformation effects on the overall strength of the Al-free and Zn-free Mg-Li alloy.These findings provide valuable insights for designing and fabricating high-strength dual-phase Mg-Li alloys.展开更多
Microstructure and corrosion resistance of an as-cast Mg-14Li-8Zn(in wt.%,LZ148)alloy subjected to solid solution treatment(T4)and aging treatment(T6)were investigated.The results revealed that the large eutectic MgLi...Microstructure and corrosion resistance of an as-cast Mg-14Li-8Zn(in wt.%,LZ148)alloy subjected to solid solution treatment(T4)and aging treatment(T6)were investigated.The results revealed that the large eutectic MgLi_(2)Zn(θ’)phase formed in as-cast LZ148 alloy were completely dissolved intoβ-Li matrix after T4 treatment,and meanwhile nanoθ’phase could be rapidly precipitated in T4 sample,and then theθ’nanoprecipitates transformed into MgLiZn(θ)phase with a moderate size after T6 treatment.The as-cast sample presented the worst corrosion resistance due to the occurrence of strong micro-galvanic effect between the cathodic eutecticθ’phase and anodicβ-Li matrix.After T4 treatment,the corrosion resistance of as-cast LZ148 alloy was dramatically improved,which was primarily ascribed to the trivial micro-galvanic effect due to the absence of noble eutecticθ’phase.In addition,the dispersed MgLi2Zn nano-precipitates and/or the homogenized distribution of alloying elements in matrix were also beneficial for the improved corrosion resistance of T4 sample.Furthermore,the lower local strain energy in the matrix of T4 sample could also contribute to the excellent corrosion resistance.However,the precipitatedθphases in T6 sample were detrimental to further improve corrosion performance due to the reactivated micro-galvanic effect.At last,the main compositions of surface film on the three samples were also revealed in detail,attributing to the different corrosion resistance of three samples as well.展开更多
Mg-8.5Li-5Zn-1Y(wt%)and Mg-8.5Li-7.5Zn-1.5Y(wt%)alloys were prepared by vacuum melting casting method.The thermal flow behavior of the alloys was systematically investigated by isothermal hot compression tests using t...Mg-8.5Li-5Zn-1Y(wt%)and Mg-8.5Li-7.5Zn-1.5Y(wt%)alloys were prepared by vacuum melting casting method.The thermal flow behavior of the alloys was systematically investigated by isothermal hot compression tests using the Gleeble-3500 thermal mechanical physical simulation system.The tests were conducted under the conditions of the temperature of 473-593 K and the strain rate of 0.001^(-1)s^(-1).A modified parameter polynomial constitutive model and thermal processing diagram for the two alloys were constructed.The variation pattern of the unstable region under different Zn and Y contents was analyzed and the safe processing region was determined.The influence of different areas in processing map on dislocation configuration and deformation mechanism was clarified.The results indicate that the higher contents of Zn and Y reduce the instability zone.Processing in the unstable zone only results inslip,while processing in the safe zone initiates<c+a>slip also.The higher contents of Zn and Y reduce the critical deformation temperature for the initiation of<c+a>slip.展开更多
To enhance the corrosion resistance of Mg-Li alloy,a composite coating system integrating plasma electrolytic oxidation(PEO)with solgel sealing treatment is developed.Two functionalized sepiolite microcontainers(sepio...To enhance the corrosion resistance of Mg-Li alloy,a composite coating system integrating plasma electrolytic oxidation(PEO)with solgel sealing treatment is developed.Two functionalized sepiolite microcontainers(sepiolite-Ce and sepiolite-BA)are constructed by loading cerium ions(Ce3+)via ion exchange and encapsulating barbituric acid(BA)through low-pressure impregnation.The microcontainers are subsequently incorporated into the coating surface through controlled sol-gel deposition process.UV-Vis and ICP-OES analyses reveal that both functionalized sepiolite microcontainers exhibited pH-responsive release characteristics under alkaline conditions.Electrochemical impedance spectroscopy(EIS)tests demonstrate that the inhibitor-containing composite coating has excellent long-term corrosion resistance and self-healing performance.After 240 h of immersion in a 0.5 wt.%NaCl solution,the low-frequency impedance modulus of the composite coating is four orders of magnitude higher than that of the pristine coating.展开更多
Designing low-density,high-strength Mg-Li alloys is a major challenge in achieving extreme lightweighting of high-end equipment.This study proposes an interpretable machine learning strategy to simultaneously enhance ...Designing low-density,high-strength Mg-Li alloys is a major challenge in achieving extreme lightweighting of high-end equipment.This study proposes an interpretable machine learning strategy to simultaneously enhance the mechanical properties and corrosion resistance of Mg-Li alloy.Key alloy factors(KAFs)influencing ultimate tensile strength(UTS),elongation(EL),and corrosion rate(CR)were identified through alloy factor construction and screening.Using KAFs and processing parameters as inputs,gradient boosting regression models for UTS,EL,and CR were established,achieving the coefficients of determination of test-set above 0.85.Then,SHapley Additive exPlanations(SHAP)analysis quantified the impact of KAFs,and an element evaluation method was established to identify Al,Si,Ca,and Zn as candidates for alloy design.Finally,three new alloys were designed via multi-objective optimization.In the hot-extruded state,they exhibited UTS of 253∼273 MPa,EL of 18.4%∼27.9%,CR of 0.55∼1.61 mg/(cm^(2)·day),and ρ of 1.49∼1.54 g/cm^(3).Compared to LAZ103,the new alloys show 34%∼44%higher UTS,35%∼79%lower CR,and comparable ρ.Microstructural analysis revealed increasedα-Mg,decreasedβ-Li,reduced coarse secondary phases,and fine Ca-/Si-rich precipitates which are conducive to grain refinement and dislocation density increasing,synergistically enhancing comprehensive property.展开更多
Mg-Li alloys hold significant potential for applications in aerospace,automotive manufacturing,military weaponry,and biomedical implants,due to their excellent recyclability,high specific strength,biocompatibility,and...Mg-Li alloys hold significant potential for applications in aerospace,automotive manufacturing,military weaponry,and biomedical implants,due to their excellent recyclability,high specific strength,biocompatibility,and superior electromagnetic shielding properties.However,their poor corrosion resistance and high susceptibility to environmentally assisted cracking(EAC)significantly limit broader application.In recent years,growing attention has been directed toward understanding the corrosion and EAC behavior of Mg-Li alloys,as localized corrosion areas and hydrogen generated during the corrosion process can serve as crack initiation points and promote crack propagation.A comprehensive understanding of these mechanisms is essential for enhancing the reliability and performance of Mg-Li alloys in practical environments.This paper presents a detailed review of corrosion and EAC in Mg-Li alloys,focusing on corrosion behavior,crack initiation and propagation mechanisms,and the key factors influencing these processes.It summarizes recent advances in alloying,heat treatment,mechanical processing,microstructural control,environmental influences,mechanical loading,and surface treatments.In addition,the paper explores future research directions,highlights emerging trends,and proposes strategies to improve the durability and service performance of Mg-Li alloys.展开更多
Here we fabricate LA103Z Mg-Li alloy via wire-arc directed energy deposition(WA-DED),and subsequent aging treatment is employed to improve its mechanical property.Results show that a typical dual-phase microstructure ...Here we fabricate LA103Z Mg-Li alloy via wire-arc directed energy deposition(WA-DED),and subsequent aging treatment is employed to improve its mechanical property.Results show that a typical dual-phase microstructure is formed upon WA-DED,consisting of α-Mg,β-Li,AlLi and Li_(2)MgAl,with negligible porosity,and the core-shell Li_(2)MgAl/AlLi composite particles are also generated.After aging treatment,the microstructure is slightly coarsened,together with the precipitation of nano-sized D0_(3)-Mg_(3)Al particles,as well as the dissolution and the mergence of α-Mg phases.Negligible strength and ductility anisotropies are found for the as-deposited alloy.Significant strength increment is achieved via aging treatment,and the ultimate strength increases by~20%(~34 MPa),reaching 200±1 MPa.Both as-deposited and aged alloys show acceptable uniform elongation,with a transgranular fracture mode.Precipitation strengthening enabled by nano-sized D0_(3)-Mg_(3)Al precipitates is primarily responsible for the strength increment mediated by aging treatment.Grain refinement strengthening and solid solution strengthening provide additional contributions to the improved strength.Our work thus offers an applicable additive manufacturing pathway for the efficient and safety-guaranteed fabrication of Mg-Li alloy components with decent mechanical property.展开更多
基金supported by the National Natural Sci-ence Foundation of China[No.51564032]Yunnan Provin-cial Department of Education Science Research Fund Project[KKPH202132005]the Analysis and Testing Founda-tion of Kunming University of Science and Technology[2022M20212130086].
文摘The performances of magnesium alloys remain insufficient to further enhance the application potential of ultralight magnesium alloys.In this work,a Mg-8Li-3Y-2Zn alloy was prepared through vacuum melting and subsequent heat treatment at 300,450,and 500°C.The material properties of the resulting samples were assessed through microstructural observation,tensile testing,electrical conductivity measurements,and electromagnetic shielding effectiveness(EMI-SE)testing.The influence of the Mg-8Li-3Y-2Zn alloy microstructure on its mechanical and electromagnetic shielding properties in different states was investigated.It was found that the as-cast alloy containsα-Mg,β-Li,Mg_(3)Zn_(3)Y_(2),and Mg_(12)ZnY phases.Following heat treatment at 500℃(HT500),the blockα-Mg phase transformedfine needle-shapes,its tensile strength increased to 263.7 MPa,and its elongation reached 45.3%.The mechanical properties of the alloy were significantly improved by the synergistic effects imparted by the needle-shapedα-Mg phase,solid solution strengthening,and precipitation strengthening.The addition of Y and Zn improved the EMI-SE of Mg-8Li-1Zn alloy,wherein the HT500 sample exhibits the highest SE,maintaining a value of 106.7–76.9 dB in the frequency range of 30–4500 MHz;this performance has rarely been reported for electromagnetically shielded alloys.This effect was mainly attributed to the multiple reflections of electromagnetic waves caused by the severe impedance mismatch of the abundant phase boundaries,which were in turn provided by the dual-phase(α/β)and secondary phases.Furthermore,the presence of nano-precipitation was also believed to enhance the absorption of electromagnetic waves.
基金financially supported by the National Natural Science Foundation of China(No.51975137,52205189)。
文摘In this work,a novel surface strengthening strategy for Mg-Li alloys was proposed,called cold spraying assisted high-speed laser cladding.CuAl9 aluminum bronze coating was firstly deposited on Mg-Li alloy by cold spraying,and then CoCrFe_(0.5)Ni_(1.5)Mo_(0.1)Nb_(0.68)eutectic highentropy alloy(EHEA)coating was prepared on the CuAl9 coating utilizing high-speed laser cladding.A gradient coating consisted of in-situ transition region and EHEA layer formed by bidirectional diffusion.The in-situ transition region was composed ofβ-Li,Cu_(2)Mg and Cu_(3)Al_(2)phases.TEM analysis indicated that Cu_(2)Mg and Cu_(3)Al_(2)phases were well matched with theβ-Li matrix phase.The EHEA coating had a nano-lamellar eutectic microstructure with relatively small lamellar-spacing(<100 nm).Metallurgical bonding interfaces formed between the EHEA coating,transition region and Mg-Li substrate.The evolution mechanism of the coating was revealed from the perspectives of mixing enthalpy,atomic radius difference and laser energy distribution.In 3.5 wt.%NaCl solution,the corrosion potential of the EHEA coating(-24 m VSHE)was 1345 m VSHEhigher than that of Mg-Li alloy(-1369 m VSHE),while the corrosion current density of the EHEA coating(3.13×10^(-7)A·cm^(-2))was almost three orders of magnitude lower than that of Mg-Li alloy(1.25×10^(-4)A·cm^(-2)).The wear rate of Mg-Li alloy(1.11×10^(-3)mm^(3)/N·m)was about 36 times higher than that of the EHEA coating(3.05×10^(-5)mm^(3)/N·m).
基金supported by a grant from the Key R&D and Transformation Plan of Science and Technology Department of Qinghai Province(No.2022-GX-156)。
文摘The process of room temperature rolling is a straightforward and efficient method for producing high strength Mg-Li alloys,but the underlying strengthening mechanism remains unclear.In this study,we successfully enhanced the tensile properties of a novel dual-phase MgLi alloy through room temperature rolling,with a remarkable yield strength of 201 MPa and an elongation-to-failure of 14%.Microhardness testing was conducted to evaluate the contribution of the Mg-and Li-phases to the improvement in strength.The results demonstrate that the hardness of Mg-phase reaches 60 HV,which is significantly higher than the 49 HV observed in Li-phase,indicating that the Mg-phase after rolling plays a pivotal role in enhancing material strength.The presence of a high density of dislocations stored in the Mg-phase emerges as the dominant factor contributing to improved strength in Mg-Li alloys.In-situ compression testing reveals thatslip activation and twinning-induced slip serve as internal mechanisms for continuous deformation and hardening within the Mg-phase.Despite numerous precipitated Mg-phase particles within the Li-phase matrix,the hardness analysis reveals minimal strain-induced phase transformation effects on the overall strength of the Al-free and Zn-free Mg-Li alloy.These findings provide valuable insights for designing and fabricating high-strength dual-phase Mg-Li alloys.
基金Tplied Basic Research Foundation of Guangdong Province(Grant Nos.2024A1515030065,2023A1515012299 and2023A1515010075)Basic and Applied Basic ResearchProject of Guangzhou(Grant Nos.2024A04J6299 and202201011454)+3 种基金Young Talent Support Project·of Guangzhou Association for Science and Technology(Grant No.QT2024-012)National Natural Science Foundation of China(Grant Nos.52101283 and 52101132)Young Elite Scientist Spon-sorship Program by CAST(Grant No.YESS20230412)National College Students Innovation and EntrepreneurshipTraining Program(Grant No.xj2024118450706)。
文摘Microstructure and corrosion resistance of an as-cast Mg-14Li-8Zn(in wt.%,LZ148)alloy subjected to solid solution treatment(T4)and aging treatment(T6)were investigated.The results revealed that the large eutectic MgLi_(2)Zn(θ’)phase formed in as-cast LZ148 alloy were completely dissolved intoβ-Li matrix after T4 treatment,and meanwhile nanoθ’phase could be rapidly precipitated in T4 sample,and then theθ’nanoprecipitates transformed into MgLiZn(θ)phase with a moderate size after T6 treatment.The as-cast sample presented the worst corrosion resistance due to the occurrence of strong micro-galvanic effect between the cathodic eutecticθ’phase and anodicβ-Li matrix.After T4 treatment,the corrosion resistance of as-cast LZ148 alloy was dramatically improved,which was primarily ascribed to the trivial micro-galvanic effect due to the absence of noble eutecticθ’phase.In addition,the dispersed MgLi2Zn nano-precipitates and/or the homogenized distribution of alloying elements in matrix were also beneficial for the improved corrosion resistance of T4 sample.Furthermore,the lower local strain energy in the matrix of T4 sample could also contribute to the excellent corrosion resistance.However,the precipitatedθphases in T6 sample were detrimental to further improve corrosion performance due to the reactivated micro-galvanic effect.At last,the main compositions of surface film on the three samples were also revealed in detail,attributing to the different corrosion resistance of three samples as well.
基金supported by the National Natural Science Foundation of China(Nos.U23A20541,U21A2049,52271098 and 52261135538)the China Postdoctoral Science Foundation(No.2023M740884)the Fundamental Research Funds for the Central Universities(Nos.3072024XX1009 and 3072024CFJ1002).
文摘Mg-8.5Li-5Zn-1Y(wt%)and Mg-8.5Li-7.5Zn-1.5Y(wt%)alloys were prepared by vacuum melting casting method.The thermal flow behavior of the alloys was systematically investigated by isothermal hot compression tests using the Gleeble-3500 thermal mechanical physical simulation system.The tests were conducted under the conditions of the temperature of 473-593 K and the strain rate of 0.001^(-1)s^(-1).A modified parameter polynomial constitutive model and thermal processing diagram for the two alloys were constructed.The variation pattern of the unstable region under different Zn and Y contents was analyzed and the safe processing region was determined.The influence of different areas in processing map on dislocation configuration and deformation mechanism was clarified.The results indicate that the higher contents of Zn and Y reduce the instability zone.Processing in the unstable zone only results inslip,while processing in the safe zone initiates<c+a>slip also.The higher contents of Zn and Y reduce the critical deformation temperature for the initiation of<c+a>slip.
基金financially supported by LiaoNing Revitalization Talents Program(XLYC2403026)Shenyang Young and Middle-aged Science and Technology Innovation Talent Support Program(RC231178)the Fundamental Research Funds for the Central Universities(N25GFY002).
文摘To enhance the corrosion resistance of Mg-Li alloy,a composite coating system integrating plasma electrolytic oxidation(PEO)with solgel sealing treatment is developed.Two functionalized sepiolite microcontainers(sepiolite-Ce and sepiolite-BA)are constructed by loading cerium ions(Ce3+)via ion exchange and encapsulating barbituric acid(BA)through low-pressure impregnation.The microcontainers are subsequently incorporated into the coating surface through controlled sol-gel deposition process.UV-Vis and ICP-OES analyses reveal that both functionalized sepiolite microcontainers exhibited pH-responsive release characteristics under alkaline conditions.Electrochemical impedance spectroscopy(EIS)tests demonstrate that the inhibitor-containing composite coating has excellent long-term corrosion resistance and self-healing performance.After 240 h of immersion in a 0.5 wt.%NaCl solution,the low-frequency impedance modulus of the composite coating is four orders of magnitude higher than that of the pristine coating.
基金supported by the Advanced Materials-National Science and Technology Major Project(No.2025ZD0619700)National Natural Science Foundation of China(No.52401002,92570301)+1 种基金China Postdoctoral Science Foundation funded project(No.2024M760200)Fundamental Research Funds for the Central Universities(No.FRF-BD-25-007).
文摘Designing low-density,high-strength Mg-Li alloys is a major challenge in achieving extreme lightweighting of high-end equipment.This study proposes an interpretable machine learning strategy to simultaneously enhance the mechanical properties and corrosion resistance of Mg-Li alloy.Key alloy factors(KAFs)influencing ultimate tensile strength(UTS),elongation(EL),and corrosion rate(CR)were identified through alloy factor construction and screening.Using KAFs and processing parameters as inputs,gradient boosting regression models for UTS,EL,and CR were established,achieving the coefficients of determination of test-set above 0.85.Then,SHapley Additive exPlanations(SHAP)analysis quantified the impact of KAFs,and an element evaluation method was established to identify Al,Si,Ca,and Zn as candidates for alloy design.Finally,three new alloys were designed via multi-objective optimization.In the hot-extruded state,they exhibited UTS of 253∼273 MPa,EL of 18.4%∼27.9%,CR of 0.55∼1.61 mg/(cm^(2)·day),and ρ of 1.49∼1.54 g/cm^(3).Compared to LAZ103,the new alloys show 34%∼44%higher UTS,35%∼79%lower CR,and comparable ρ.Microstructural analysis revealed increasedα-Mg,decreasedβ-Li,reduced coarse secondary phases,and fine Ca-/Si-rich precipitates which are conducive to grain refinement and dislocation density increasing,synergistically enhancing comprehensive property.
基金supported by the National Natural Science Foundation of China Projects under Grant(nos.52301112,52331004,U21A2049,and 51871211)Guangdong Basic and Applied Basic Research Foundation(Grant no.2024A1515030065)+4 种基金Basic and Applied Basic Research Project of Guangzhou(Grant no.2024A04J6299)LiaoNing Revitalization Talents Program(XLYC1907062,and XLYC2403026)Shenyang Young and Middle-aged Science and Technology Innovation Talent Support Program(RC231178)the Fundamental Research Funds for the Central Universities(N25GFY002)the Innovation Fund of Institute of Metal Research(IMR),Chinese Academy of Sciences(CAS).
文摘Mg-Li alloys hold significant potential for applications in aerospace,automotive manufacturing,military weaponry,and biomedical implants,due to their excellent recyclability,high specific strength,biocompatibility,and superior electromagnetic shielding properties.However,their poor corrosion resistance and high susceptibility to environmentally assisted cracking(EAC)significantly limit broader application.In recent years,growing attention has been directed toward understanding the corrosion and EAC behavior of Mg-Li alloys,as localized corrosion areas and hydrogen generated during the corrosion process can serve as crack initiation points and promote crack propagation.A comprehensive understanding of these mechanisms is essential for enhancing the reliability and performance of Mg-Li alloys in practical environments.This paper presents a detailed review of corrosion and EAC in Mg-Li alloys,focusing on corrosion behavior,crack initiation and propagation mechanisms,and the key factors influencing these processes.It summarizes recent advances in alloying,heat treatment,mechanical processing,microstructural control,environmental influences,mechanical loading,and surface treatments.In addition,the paper explores future research directions,highlights emerging trends,and proposes strategies to improve the durability and service performance of Mg-Li alloys.
基金supported by the National Natural Science Foundation of China(52475320).
文摘Here we fabricate LA103Z Mg-Li alloy via wire-arc directed energy deposition(WA-DED),and subsequent aging treatment is employed to improve its mechanical property.Results show that a typical dual-phase microstructure is formed upon WA-DED,consisting of α-Mg,β-Li,AlLi and Li_(2)MgAl,with negligible porosity,and the core-shell Li_(2)MgAl/AlLi composite particles are also generated.After aging treatment,the microstructure is slightly coarsened,together with the precipitation of nano-sized D0_(3)-Mg_(3)Al particles,as well as the dissolution and the mergence of α-Mg phases.Negligible strength and ductility anisotropies are found for the as-deposited alloy.Significant strength increment is achieved via aging treatment,and the ultimate strength increases by~20%(~34 MPa),reaching 200±1 MPa.Both as-deposited and aged alloys show acceptable uniform elongation,with a transgranular fracture mode.Precipitation strengthening enabled by nano-sized D0_(3)-Mg_(3)Al precipitates is primarily responsible for the strength increment mediated by aging treatment.Grain refinement strengthening and solid solution strengthening provide additional contributions to the improved strength.Our work thus offers an applicable additive manufacturing pathway for the efficient and safety-guaranteed fabrication of Mg-Li alloy components with decent mechanical property.
