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Transformation of long-period stacking ordered structures in Mg-Gd-Y-Zn alloys upon synergistic characterization of first-principles calculation and experiment and its effects on mechanical properties 被引量:1
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作者 Mingyu Li Guangzong Zhang +4 位作者 Siqi Yin Changfeng Wang Ying Fu Chenyang Gu Renguo Guan 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第5期1867-1879,共13页
Based on experiments and first-principles calculations,the microstructures and mechanical properties of as-cast and solution treated Mg-10Gd-4Y-xZn-0.6Zr(x=0,1,2,wt.%)alloys are investigated.The transformation process... Based on experiments and first-principles calculations,the microstructures and mechanical properties of as-cast and solution treated Mg-10Gd-4Y-xZn-0.6Zr(x=0,1,2,wt.%)alloys are investigated.The transformation process of long-period stacking ordered(LPSO)structure during solidification and heat treatment and its effect on the mechanical properties of experimental alloys are discussed.Results reveal that the stacking faults and 18R LPSO phases appear in the as-cast Mg-10Gd-4Y-1Zn-0.6Zr and Mg-10Gd-4Y-2Zn-0.6Zr alloys,respectively.After solution treatment,the stacking faults and 18R LPSO phase transform into 14H LPSO phase.The Enthalpies of formation and reaction energy of 14H and 18R LPSO are calculated based on first-principles.Results show that the alloying ability of 18R is stronger than that of 14H.The reaction energies show that the 14H LPSO phase is more stable than the 18R LPSO.The elastic properties of the 14H and 18R LPSO phases are also evaluated by first-principles calculations,and the results are in good agreement with the experimental results.The precipitation of LPSO phase improves the tensile strength,yield strength and elongation of the alloy.After solution treatment,the Mg-10Gd-4Y-2Zn-0.6Zr alloy has the best mechanical properties,and its ultimate tensile strength and yield strength are 278.7 MPa and 196.4 MPa,respectively.The elongation of Mg-10Gd-4Y-2Zn-0.6Zr reaches 15.1,which is higher than that of Mg-10Gd-4Y0.6Zr alloy.The improving mechanism of elastic modulus by the LPSO phases and the influence on the alloy mechanical properties are also analyzed. 展开更多
关键词 mg-gd-y-zn alloys Long-period stacking ordered First-principles calculations ENTHALPIES Mechanical properties
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Phase equilibria and microstructure investigation of Mg-Gd-Y-Zn alloy system 被引量:2
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作者 Janet M.Meier Jiashi Miao +4 位作者 Song-Mao Liang Jun Zhu Chuan Zhang Josh Caris Alan A.Luo 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2022年第3期746-755,共10页
In order to develop high strength Mg-Gd-Y-Zn alloys,key experiments coupled with CALPHAD(CALculation of PHAse Diagrams)calculations were carried out in the current work to provide critical understanding of this import... In order to develop high strength Mg-Gd-Y-Zn alloys,key experiments coupled with CALPHAD(CALculation of PHAse Diagrams)calculations were carried out in the current work to provide critical understanding of this important alloy system.Three Mg-10 Gd-xY-yZn(x=4 or 5,y=3 or 5,wt.%) were mapped on Mg-Gd-Y-Zn phase diagrams for phase equilibria and microstructure investigation.Electron microscopy was performed for phase identification and phase fraction determination in as-cast and solution treated conditions.In all three alloys,the major phases were Mg-matrix and long period stacking order(LPSO) 14 H phase.With ST at 400 and 500℃,the phase fraction of LPSO 14 H increased,particularly the fine lamellar morphology in the Mg matrix.The as-cast and 400℃ Mg10 Gd5 Y3 Zn samples had Mg(Gd,Y) present.At 500℃,Mg(Gd,Y) is not stable and transforms into LPSO 14 H.The Mg 10 Gd5 Y5 Zn alloy included the WPhase,which showed a reduction in phase fraction with solution treatment.These experimental results were used to validate and improve the thermodynamic database of the Mg-Gd-Y-Zn system.Thermodynamic calculations using the improved database can well describe the available experimental results and make accurate predictions to guide the development of promising high-strength Mg-Gd-Y-Zn alloys. 展开更多
关键词 Long period stacking order(LPSO) MICROSTRUCTURE Magnesium alloys CALPHAD alloy development.
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Linear Shaped Charge Cutting Property and Charge Cutting Mechanism of Mg-Gd-Y-Zn Alloy
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作者 WANG Yanbo ZHOU Haitao +4 位作者 XIAO Lü HOU Xiangwu SUN Xin CHEN Ge DONG Xiwang 《上海航天(中英文)》 CSCD 2022年第1期196-204,共9页
The linear shaped charge cutting technology is an effective technology for aircraft separation.It can separate invalid components from aircrafts timely to achieve light-weight.Magnesium alloy is the lightest metal mat... The linear shaped charge cutting technology is an effective technology for aircraft separation.It can separate invalid components from aircrafts timely to achieve light-weight.Magnesium alloy is the lightest metal material,and can be used to cast effective light-weight components of an aircraft construction.However,the application study of the linear shaped charge cutting technology on magnesium alloy components is basically blank.In response to the demand for the linear separation of magnesium alloys,the Mg-12Gd-0.5Y-0.4Zn alloy is selected to carry out the target shaped charge cutting test.The effects of the shaped charge line density,cutting thickness,and mechanical properties on the cutting performance of the alloy are studied.The shaped charge cutting mechanism is analyzed through the notch structure.The results show that the linear shaped charge cutting performance is significantly affected by the penetration and the collapse.The higher the linear density is,the stronger the ability of the linear shaped charge cutter is,and the greater the penetration depth is,which is advantageous.However,the target structure will be damaged when it is too large(e.g.,4.5 g·m^(-1)).Within 12 mm,when the cutting thickness of the target increases,the penetration depth increases.The lower the tensile strength is,the greater the penetration depth is,and the more conducive the penetration depth to the shaped charge cutting is.When the elongation(EL)increases to 12%,the collapse of the target is incomplete and the target cannot be separated.When the tensile strength of the Mg-Gd-Y-Zn alloy is less than 350 MPa,the EL is less than 6.5%,the cutting thickness is less than 12 mm,and the linear shaped charge cutting of the magnesium alloy can be achieved stably. 展开更多
关键词 shaped charge cutting linear shaped charge cutting mechanism magnesium alloy mechanical properties PENETRATION
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A new insight into LPSO phase transformation and mechanical properties uniformity of large-scale Mg-Gd-Y-Zn-Zr alloy prepared by multi-pass friction stir processing 被引量:1
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作者 Xiaohu Guan Wen Wang +7 位作者 Ting Zhang Pai Peng Qiang Liu Peng Han Ke Qiao Jun Cai Liqiang Wang Kuaishe Wang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第5期2041-2056,共16页
A large-scale fine-grained Mg-Gd-Y-Zn-Zr alloy plate with high strength and ductility was successfully prepared by multi-pass friction stir processing(MFSP)technology in this work.The structure of grains and long peri... A large-scale fine-grained Mg-Gd-Y-Zn-Zr alloy plate with high strength and ductility was successfully prepared by multi-pass friction stir processing(MFSP)technology in this work.The structure of grains and long period stacking ordered(LPSO)phase were characterized,and the mechanical properties uniformity was investigated.Moreover,a quantitative relationship between the microstructure and tensile yield strength was established.The results showed that the grains in the processed zone(PZ)and interfacial zone(IZ)were refined from 50μm to 3μm and 4μm,respectively,and numerous original LPSO phases were broken.In IZ,some block-shaped 18R LPSO phases were transformed into needle-like 14H LPSO phases due to stacking faults and the short-range diffusion of solute atoms.The severe shear deformation in the form of kinetic energy caused profuse stacking fault to be generated and move rapidly,greatly increasing the transformation rate of LPSO phase.After MFSP,the ultimate tensile strength,yield strength and elongation to failure of the large-scale plate were 367 MPa,305 MPa and 18.0% respectively.Grain refinement and LPSO phase strengthening were the major strengthening mechanisms for the MFSP sample.In particularly,the strength of IZ was comparable to that of PZ because the strength contribution of the 14H LPSO phase offsets the lack of grain refinement strengthening in IZ.This result opposes the widely accepted notion that IZ is a weak region in MFSP-prepared large-scale fine-grained plate. 展开更多
关键词 Friction stir processing MULTI-PASS mg-gd-y-zn-Zr alloy LPSO phase transformation Mechanical properties
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Solid state recycling of Mg-Gd-Y-Zn-Zr alloy chips by isothermal sintering and equal channel angular pressing
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作者 Yanbo Pei Hongjun Ma +1 位作者 Meng Yuan Bugang Teng 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第7期2725-2740,共16页
The Mg-7Gd-4Y-2Zn-0.5Zr alloy chips were successfully recycled through isothermal sintering and equal channel angular pressing(ECAP).The mechanical properties and microstructure evolution of samples during the recycli... The Mg-7Gd-4Y-2Zn-0.5Zr alloy chips were successfully recycled through isothermal sintering and equal channel angular pressing(ECAP).The mechanical properties and microstructure evolution of samples during the recycling process were studied in detail.The eutectic phases in the as-cast alloy transform into long period-stacking ordered(LPSO)phases after homogenization,which can improve the plasticity of the material.After isothermal sintering,the density of the sample is lower than that of the homogenized sample,and oxide films are formed adjacent to the bonding interface of the metal chips.Hence,the plasticity of the sintered sample is poor.Dense samples are fabricated after ECAP.Although the grains are not refined compared to the sintered sample,the microstructure becomes more uniform due to recrystallization.Fiber interdendritic LPSO phase and kinked 14H-LPSO phase are formed in the alloy due to the shear deformation during the ECAP process,which improves the strength and plasticity of the sample significantly.Furthermore,the basal texture is weakened due to the Bc route of the ECAP process,which can increase the Schmid factor of the basal slip system and improve the elongation of the sample.After 2 ECAP passes,the fully densified recycled billet shows superior mechanical properties with an ultimate tensile strength of 307.1 MPa and elongation of 11.1%. 展开更多
关键词 mg-gd-y-zn-Zr alloy Solid state recycling Microstructure evolution LPSO phase Equal channel angular pressing
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Preparation of FeCoNi medium entropy alloy from Fe^(3+)-Co^(2+)-Ni^(2+)solution system
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作者 Zongyou Cheng Qing Zhao +3 位作者 Mengjie Tao Jijun Du Xingxi Huang Chengjun Liu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第1期92-101,共10页
In recent years,medium entropy alloys have become a research hotspot due to their excellent physical and chemical performances.By controlling reasonable elemental composition and processing parameters,the medium entro... In recent years,medium entropy alloys have become a research hotspot due to their excellent physical and chemical performances.By controlling reasonable elemental composition and processing parameters,the medium entropy alloys can exhibit similar properties to high entropy alloys and have lower costs.In this paper,a FeCoNi medium entropy alloy precursor was prepared via sol-gel and coprecipitation methods,respectively,and FeCoNi medium entropy alloys were prepared by carbothermal and hydrogen reduction.The phases and magnetic properties of FeCoNi medium entropy alloy were investigated.Results showed that FeCoNi medium entropy alloy was produced by carbothermal and hydrogen reduction at 1500℃.Some carbon was detected in the FeCoNi medium entropy alloy prepared by carbothermal reduction.The alloy prepared by hydrogen reduction was uniform and showed a relatively high purity.Moreover,the hydrogen reduction product exhibited better saturation magnetization and lower coercivity. 展开更多
关键词 medium entropy alloy SOL-GEL CO-PRECIPITATION carbothermal hydrogen reduction
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Influence of introducing Zr,Ti,Nb and Ce elements on externally solidified crystals and mechanical properties of high-pressure die-casting Al–Si alloy
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作者 Junjie Li Wenbo Yu +5 位作者 Zhenyu Sun Weichen Zheng Liangwei Zhang Yanling Xue Wenning Liu Shoumei Xiong 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第1期147-153,共7页
High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile industry.Mg can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress aro... High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile industry.Mg can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress arouses the deformation of large integrated die-castings.Herein,the development of non-heat treatment Al alloys is becoming the hot topic.In addition,HPDC contains externally solidified crystals(ESCs),which are detrimental to the mechanical properties of castings.To achieve high strength and toughness of non-heat treatment die-casting Al-Si alloy,we used AlSi9Mn alloy as matrix with the introduction of Zr,Ti,Nb,and Ce.Their influences on ESCs and mechanical properties were systematically investigated through three-dimensional reconstruction and thermodynamic simulation.Our results reveal that the addition of Ti increased ESCs'size and porosity,while the introduction of Nb refined ESCs and decreased porosity.Meanwhile,large-sized Al_3(Zr,Ti)phases formed and degraded the mechanical properties.Subsequent introduction of Ce resulted in the poisoning effect and reduced mechanical properties. 展开更多
关键词 aluminium alloy high-pressure die-casting externally solidified crystals non-heat treatment
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Effects of the extrusion parameters on microstructure,texture and room temperature mechanical properties of extruded Mg-2.49Nd-1.82Gd-0.2Zn-0.2Zr alloy
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作者 Chenjin Zhang Guangyu Yang +4 位作者 Lei Xiao Zhiyong Kan Jing Guo Qiang Li Wanqi Jie 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第1期136-146,共11页
Microstructure,texture,and mechanical properties of the extruded Mg-2.49Nd-1.82Gd-0.2Zn-0.2Zr alloy were investigated at different extrusion temperatures(260 and 320℃),extrusion ratios(10:1,15:1,and 30:1),and extrusi... Microstructure,texture,and mechanical properties of the extruded Mg-2.49Nd-1.82Gd-0.2Zn-0.2Zr alloy were investigated at different extrusion temperatures(260 and 320℃),extrusion ratios(10:1,15:1,and 30:1),and extrusion speeds(3 and 6 mm/s).The experimental results exhibited that the grain sizes after extrusion were much finer than that of the homogenized alloy,and the second phase showed streamline distribution along the extrusion direction(ED).With extrusion temperature increased from 260 to 320℃,the microstructure,texture,and mechanical properties of alloys changed slightly.The dynamic recrystallization(DRX)degree and grain sizes enhanced as the extrusion ratio increased from 10:1 to 30:1,and the strength gradually decreased but elongation(EL)increased.With the extrusion speed increased from 3 to 6 mm/s,the grain sizes and DRX degree increased significantly,and the samples presented the typical<2111>-<1123>rare-earth(RE)textures.The alloy extruded at 260℃ with extrusion ratio of 10:1 and extrusion speed of 3 mm/s showed the tensile yield strength(TYS)of 213 MPa and EL of 30.6%.After quantitatively analyzing the contribution of strengthening mechanisms,it was found that the grain boundary strengthening and dislocation strengthening played major roles among strengthening contributions.These results provide some guidelines for enlarging the industrial application of extruded Mg-RE alloy. 展开更多
关键词 Mg-rare earth alloys extrusion temperature extrusion ratio extrusion speed strengthening mechanisms
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Study on the hydrogen absorption properties of a YGdTbDyHo rare-earth high-entropy alloy
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作者 Tongyue Li Ziliang Xie +5 位作者 Wenjiao Zhou Huan Tong Dawen Yang Anjia Zhang Yuan Wu Xiping Song 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第1期127-135,共9页
This study investigated the microstructure and hydrogen absorption properties of a rare-earth high-entropy alloy(HEA),YGdTbDyHo.Results indicated that the YGdTbDyHo alloy had a microstructure of equiaxed grains,with t... This study investigated the microstructure and hydrogen absorption properties of a rare-earth high-entropy alloy(HEA),YGdTbDyHo.Results indicated that the YGdTbDyHo alloy had a microstructure of equiaxed grains,with the alloy elements distributed homogeneously.Upon hydrogen absorption,the phase structure of the HEA changed from a solid solution with an hexagonal-close-packed(HCP)structure to a high-entropy hydride with an faced-centered-cubic(FCC)structure without any secondary phase precipitated.The alloy demonstrated a maximum hydrogen storage capacity of 2.33 H/M(hydrogen atom/metal atom)at 723 K,with an enthalpy change(ΔH)of-141.09 kJ·mol^(-1)and an entropy change(ΔS)of-119.14 J·mol^(-1)·K^(-1).The kinetic mechanism of hydrogen absorption was hydride nucleation and growth,with an apparent activation energy(E_(a))of 20.90 kJ·mol^(-1).Without any activation,the YGdTbDyHo alloy could absorb hydrogen quickly(180 s at 923 K)with nearly no incubation period observed.The reason for the obtained value of 2.33 H/M was that the hydrogen atoms occupied both tetrahedral and octahedral interstices.These results demonstrate the potential application of HEAs as a high-capacity hydrogen storage material with a large H/M ratio,which can be used in the deuterium storage field. 展开更多
关键词 RARE-EARTH high-entropy alloy hydrogen absorption capacity pressure–composition–temperature curves KINETICS
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Enhancing strength and creep resistance of Mg-Gd-Y-Zn-Zr alloy by substituting Mn for Zr 被引量:17
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作者 C.Xu T.Nakata +3 位作者 G.H.Fan X.W.Li G.Z.Tang S.Kamado 《Journal of Magnesium and Alloys》 SCIE 2019年第3期388-399,共12页
The age-hardening behavior and mechanical properties of the extruded Mg-2Gd-1.2Y-0.5Zn(at.%)alloy with Zr or Mn additions were investigated.The results show that Mn added alloy exhibits more remarkable age-hardening r... The age-hardening behavior and mechanical properties of the extruded Mg-2Gd-1.2Y-0.5Zn(at.%)alloy with Zr or Mn additions were investigated.The results show that Mn added alloy exhibits more remarkable age-hardening response than Zr added alloy,which is attributed to the fact that partitioning of Mn into the β'phases,β'precipitates and long period stacking ordered(LPSO)phases leads to the decrement in(G d+Y)concentrations in the second phases,facilitating the precipitation during aging treatment.Both peak-aged alloys show bimodal microstructure comprising the fine DRXed grains with nano-sized β phases pinned at DRXed grain boundaries as well as coarse worked grains with strong fiber texture.High strength and good thermal stability were obtained in both peak-aged Mn and Zr added alloys.While the peak-aged Mn added alloy shows higher strength and superior creep resistance due to its denser β'precipitates,thin LPSO phases and γ'precipitates and higher area fraction of worked grains with strong fiber texture.The 0.2% tensile proof stress and ultimate tensile strength of peak-aged Mn added alloy reach up to 454 MPa and 508 MPa,respectively,with elongation of 3.2%at room temperature.The minimum creep rate of the peak-aged Mn added alloy at 250℃/150 MPa is 2.4 × 10^-8 s^-1,which is superior than previously reported extruded Mg-Gd based alloys. 展开更多
关键词 Magnesium alloys Rare earth(RE) PRECIPITATION Mechanical properties Creep resistance
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Substitution of Ni for Zn on microstructure and mechanical properties of Mg-Gd-Y-Zn-Mn alloy 被引量:5
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作者 Rongqing Zhang Jingfeng Wang +2 位作者 Song Huang Shijie Liu Fusheng Pan 《Journal of Magnesium and Alloys》 SCIE EI CAS 2017年第3期355-361,共7页
This study analyzes the effect of substitution of Ni for Zn on microstructure and mechanical properties of Mg-Gd-Y-Zn-Mn alloy.Our results show that the volume fraction of Mg5(Gd,Y)and(Mg,Zn)3RE phase decreased and LP... This study analyzes the effect of substitution of Ni for Zn on microstructure and mechanical properties of Mg-Gd-Y-Zn-Mn alloy.Our results show that the volume fraction of Mg5(Gd,Y)and(Mg,Zn)3RE phase decreased and LPSO phase increased with more substitution of Ni.After homogenization,onlyα-Mg and LPSO phase existed.In Mg-Gd-Y-Zn-Mn alloys,the LPSO phases mainly consisted of the 14H type.While in Mg-Gd-Y-Ni-Mn alloy,the LPSO phases consisted of the 18R type.In addition,compared with Mg-Gd-Y-Zn-Mn alloy,the mechanical properties of as-extruded Ni-substitution alloys were improved due to the better refinement of the size of grains and LPSO phases.The tensile strength in as-extruded Mg-Gd-Y-Ni-Mn alloy could reach up to 400 MPa with 18%of the elongation to failure. 展开更多
关键词 Magnesium alloy SUBSTITUTION Microstructure Mechanical property LPSO phase
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The effect of LPSO on the deformation mechanism of Mg-Gd-Y-Zn-Zr magnesium alloy 被引量:6
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作者 Jianbo Shao Zhiyong Chen +3 位作者 Tao Chen Zhang Hu Xiaojie Zhou Chuming Liu 《Journal of Magnesium and Alloys》 SCIE EI CAS 2016年第2期83-88,共6页
The tensile deformation behavior and corresponding microstructure evolution of the Mg-4.7Gd-3.4Y-1.2Zn-0.5Zr(at.%)magnesium alloy with long period stacking structure(LPSO)are studied by electron backscatter diffractio... The tensile deformation behavior and corresponding microstructure evolution of the Mg-4.7Gd-3.4Y-1.2Zn-0.5Zr(at.%)magnesium alloy with long period stacking structure(LPSO)are studied by electron backscatter diffraction(EBSD)and slip lines methods.The results show that less and very small size of twins is observed in the grains with high value of Schmid factor for twinning,which indicates that the growth of the{10–12}twinning deformation is prevented by the LPSO phase.The prismatic lines present in grains of which the prismatic slip Schmid factor is above 0.4.The favorable orientation and LPSO phase synergistically promote the activation of prismatic slip.The inhomogeneous rotation of the grains during deformation is the reason for the microcrack at grain boundary. 展开更多
关键词 Rare earth magnesium alloys LPSO Deformation mechanism Crystal orientation
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A novel Mg-Gd-Y-Zn-Cu-Ni alloy with excellent combination of strength and dissolution via peak-aging treatment 被引量:4
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作者 Y.H.Liu Z.R.Zhang +5 位作者 J.Wang Y.Li H.X.Li L.Y.Jia J.H.Wang J.S.Zhang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第2期720-734,共15页
Inferior absolute strength and dissolution properties are the main bottlenecks for the widespread application of dissolvable magnesium alloys in complex working environments for unconventional oil and gas resources.He... Inferior absolute strength and dissolution properties are the main bottlenecks for the widespread application of dissolvable magnesium alloys in complex working environments for unconventional oil and gas resources.Here,a novel functional peak-aged Mg-9.5Gd-2.7Y-0.9Zn-0.8Cu-0.4Ni(wt.%) alloy for fracturing tools is reported,and it possesses an ultimate tensile strength of 457.6 MPa,ultimate compressive strength of 620.7 MPa and dissolution rate of ~43.7 mg·cm^(-2)·h^(-1) in 3 wt.% KCl solutions at 93℃.The excellent strength of the agedalloy is primarily attributed to the combination of grain refinement,long-period stacking ordered(LPSO) strengthening,and precipitation strengthening induced by stacking fault and β’ phase,among which the precipitation strengthening is dominant.Further investigations confirm that the corrosion is triggered from the micro-galvanic coupling between the Mg matrix and the cathodic lamellar and block LPSO phases.Strip-shaped corrosion pits along with LPSO phases are subsequently formed,significantly accelerating corrosion.The β’ precipitates can effectively improve the strength without compromising the dissolution rate because of their nanoscale size.This study provides an excellent material selection for dissolvable fracturing tools and presents a strategy by which a synergistic combination of strength and dissolution rate is achieved via peak-aging treatment. 展开更多
关键词 Dissolvable magnesium alloy Peak-aging treatment Mechanical properties Micro-galvanic corrosion
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Effect of heat treatment on the microstructure and mechanical properties of a multidirectionally forged Mg-Gd-Y-Zn-Zr-Ag alloy 被引量:4
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作者 Junkai Wang Chuming Liu +2 位作者 Shunong Jiang Yingchun Wan Zhiyong Chen 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第6期2042-2053,共12页
Multidirectional forging(MDF)was successfully applied to fabricate large-size Mg-Gd-Y-Zn-Zr-Ag alloy in this work and effects of T4,T5 and T6 treatments on the microstructure and mechanical properties of the as-forged... Multidirectional forging(MDF)was successfully applied to fabricate large-size Mg-Gd-Y-Zn-Zr-Ag alloy in this work and effects of T4,T5 and T6 treatments on the microstructure and mechanical properties of the as-forged alloy were analyzed.Results show that dynamic recrystallization(DRX)occurs and second phase particles precipitate along the grain boundary during the MDF process.After annealing treatment(T4),the volume fraction and size of dynamic precipitates slightly increase at a lower temperature(430℃)compared with those of MDFed sample,while they are dissolved into theα-Mg matrix at a higher temperature(450℃).At the meantime,short plate-shaped long-period stacking ordered(LPSO)phases are observed in the DRX grains of the MDFed sample and then dissolved into theα-Mg matrix during annealing at both temperatures.Typical basal texture is identified in the MDFed sample,but the basal pole tilts away from final forging direction and rare-earth texture component with<1121>orientation parallel to penultimate forging direction becomes visible after annealing.The T6 sample annealing at 430℃for 4 h and ageing at 200℃for 34 h exhibits the superior strength and ductility in this study.The ultimate tensile strength,tensile yield strength and elongation to failure,which is 455 MPa,308 MPa and 7.7%,respectively,are overall improved compared with the directly-aged(T5)sample.This paper provides a superior heat treatment schedule to manufacture high-performance large-scale Mg-Gd-Y-Zn-Zr-Ag components for industrial production. 展开更多
关键词 mg-gd-y-zn-Zr-Ag alloy Multidirectional forging Dynamic precipitation Heat treatment Mechanical properties
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Effect of aging treatment on the precipitation transformation and age hardening of Mg-Gd-Y-Zn-Zr alloy 被引量:2
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作者 Mu Meng Honglei Zhang +2 位作者 Zhi Gao Genxing Lei Jianmin Yu 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第12期4628-4643,共16页
In this study, the precipitation transformation and age hardening of solution-treated Mg-9Gd-4Y-2Zn-0.5Zr(wt.%) alloy were investigated at different aging treatment parameters. The precipitation sequences of the alloy... In this study, the precipitation transformation and age hardening of solution-treated Mg-9Gd-4Y-2Zn-0.5Zr(wt.%) alloy were investigated at different aging treatment parameters. The precipitation sequences of the alloy aged at 200℃, 250℃ and 300℃ are β’’(DO19) → β’(BCO) → β(FCC), β’’(DO19) → β’(BCO) → β_(1)(FCC) → β(FCC) and β(FCC), respectively. The streaks sequences of the alloy aged at 200℃, 250℃ and 300℃ are SF, SF → 14H-LPSO and SF → 14H-LPSO, respectively. For the alloy aged at 200℃ and 250℃, the increase in hardness with increasing aging time is contributed from the increase in precipitate volume fraction and the transformation from β’’ to β’ phase with basal → prismatic and spherical → spindle-like precipitate changes. The decrease in hardness after the peak-aging stage is attributed to the appearance of micro-sized β precipitates. Because of the smaller size of precipitates and the triangular arrangement of β’ precipitate, the hardness of the alloy aged at 200℃ is higher than that aged at 250℃. For the alloy aged at 300℃, the appearance of only micro-sized β precipitate and its coarsening with increasing aging time leads to the lowest hardness and an overall decrease in hardness with the aging time. 展开更多
关键词 mg-gd-y-zn-Zr alloy Aging treatment Precipitation transformation Age hardening
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The hot compressive deformation behavior of cast Mg-Gd-Y-Zn-Zr alloys with and without LPSO phase in their initial microstructures 被引量:5
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作者 H.T.Jeong W.J.Kim 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2022年第10期2901-2917,共17页
Samples of Mg-8.2Gd-3.8Y-1.1Zn-0.4Zr alloy with and without an intragranular lamellae-shaped long period stacking ordered(LPSO)phase were prepared through heat treatment and a series of hot compression tests on these ... Samples of Mg-8.2Gd-3.8Y-1.1Zn-0.4Zr alloy with and without an intragranular lamellae-shaped long period stacking ordered(LPSO)phase were prepared through heat treatment and a series of hot compression tests on these materials were conducted to examine and evaluate the influence of LPSO on the hot compressive deformation behavior and deformation mechanisms at a given alloy composition.The values of activation energy for plastic flow(Qc)of the solution treated(without LPSO phase)and annealed alloys(with intragranular LPSO phase)were larger than that for pure Mg,indicating that the presence of a high amount of rare earth(RE)elements and LPSO in the Mg matrix significantly increases Qc.The Qcvalue of the annealed alloy was larger than that of the solution treated alloy at all the strain levels(223.3 vs.195.5 k J/mol in average)and the largest difference in Qcbetween the two alloys was recorded at the smallest strain of 0.1 where precipitation of LPSO during deformation was limited in the solution treated alloy.These observations imply that the formation of LPSO phase out of the RE-rich solid solution matrix during deformation increases Qc,but the increment is not so large.Analysis of the hot compressive data of the alloys with LPSO phase and the alloys with RE-rich solid solution matrix in literatures indicates the similarity of the effect of the LPSO and RE-rich solid solution matrix phases on Qcand high-temperature strength. 展开更多
关键词 Magnesium alloys LPSO Deformation mechanism Dynamic recrystallization Activation energy for plastic flow Processing maps
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Study on the Deformation Behavior of Mg-Gd-Y-Zn-Mn Wrought Magnesium Alloys by Visco-plastic Self-consistent Modeling 被引量:1
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作者 WANG Yuye ZHANG Junfa +5 位作者 WANG Shiwei KANG Jing MENG Jiajie WANG Yanbo XU Yuling ZHOU Haitao 《上海航天(中英文)》 CSCD 2022年第1期77-83,136,共8页
The plastic deformation behavior of new Mg-Gd-Y-Zn-Mn magnesium alloys gains great necessity to clarify and understand the mechanism deeply. In the present work,the tensile mechanical property test and visco-plastic s... The plastic deformation behavior of new Mg-Gd-Y-Zn-Mn magnesium alloys gains great necessity to clarify and understand the mechanism deeply. In the present work,the tensile mechanical property test and visco-plastic self-consistent (VPSC) model are used to investigate the activities of deformation modes of VW84M and VW94M magnesium alloys during the tensile deformation. The results show that the mechanical properties of the above extruded alloys are similar but VW94M has higher strength than VW84M after the same aging process. Compared with the extruded alloys,the as-aged alloys have significantly higher activation of pyramidal slip at the later stage of plastic deformation. In addition,the as-aged VW94M alloy with higher strength has the largest activity of pyramidal slip. In summary,the addition of Gd increases the critical resolved shear stress (CRSS)in each slip system of VW94M,while the increase in the strength and the decrease in the elongation of as-aged alloys are associated with the significant activation of pyramidal slip. 展开更多
关键词 Mg-RE alloy wrought magnesium alloy visco-plastic self-consistent(VPSC)model deformation behavior
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Microstructure evolution during heat treatment of Mg-Gd-Y-Zn-Zr alloy and its low-cycle fatigue behavior at 573K 被引量:7
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作者 Luo-yi WU Hao-tian LI Zhong YANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第5期1026-1035,共10页
In as-cast Mg?2.1Gd?1.1Y?0.82Zn?0.11Zr(mole fraction,%)alloy,lamellar microstructures that extend from grain boundaries to the interior ofα-Mg grains are identified as clusters ofγ′using a scanning transmission ele... In as-cast Mg?2.1Gd?1.1Y?0.82Zn?0.11Zr(mole fraction,%)alloy,lamellar microstructures that extend from grain boundaries to the interior ofα-Mg grains are identified as clusters ofγ′using a scanning transmission electron microscope equipped with a high-angle annular dark-field detector.Under a total strain-controlled low-cyclic loading at573K,the mechanical response and failure mechanism of Mg?2.1Gd?1.1Y?0.82Zn?0.11Zr alloy(T6peak-aging heat treatment)were investigated.Results show that the alloy exhibits cyclic softening response at diverse total strain amplitudes and573K.The experimental observations using scanning electron microscopy show that the micro-cracks initiate preferentially at the interface between long-period stacking order structures andα-Mg matrix and extend along the basal plane ofα-Mg.The massive long-period stacking order structures distributed at grain boundaries impede the transgranular propagation of cracks. 展开更多
关键词 Mg.Gd.Y.Zn.Zr alloy long-period stacking order structure low-cycle fatigue at high temperature crack initiation and propagation
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Accelerated design of high-performance Mg-Mn-based magnesium alloys based on novel bayesian optimization 被引量:2
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作者 Xiaoxi Mi Lili Dai +4 位作者 Xuerui Jing Jia She Bjørn Holmedal Aitao Tang Fusheng Pan 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第2期750-766,共17页
Magnesium(Mg),being the lightest structural metal,holds immense potential for widespread applications in various fields.The development of high-performance and cost-effective Mg alloys is crucial to further advancing ... Magnesium(Mg),being the lightest structural metal,holds immense potential for widespread applications in various fields.The development of high-performance and cost-effective Mg alloys is crucial to further advancing their commercial utilization.With the rapid advancement of machine learning(ML)technology in recent years,the“data-driven''approach for alloy design has provided new perspectives and opportunities for enhancing the performance of Mg alloys.This paper introduces a novel regression-based Bayesian optimization active learning model(RBOALM)for the development of high-performance Mg-Mn-based wrought alloys.RBOALM employs active learning to automatically explore optimal alloy compositions and process parameters within predefined ranges,facilitating the discovery of superior alloy combinations.This model further integrates pre-established regression models as surrogate functions in Bayesian optimization,significantly enhancing the precision of the design process.Leveraging RBOALM,several new high-performance alloys have been successfully designed and prepared.Notably,after mechanical property testing of the designed alloys,the Mg-2.1Zn-2.0Mn-0.5Sn-0.1Ca alloy demonstrates exceptional mechanical properties,including an ultimate tensile strength of 406 MPa,a yield strength of 287 MPa,and a 23%fracture elongation.Furthermore,the Mg-2.7Mn-0.5Al-0.1Ca alloy exhibits an ultimate tensile strength of 211 MPa,coupled with a remarkable 41%fracture elongation. 展开更多
关键词 Mg-Mn-based alloys HIGH-PERFORMANCE alloy design Machine learning Bayesian optimization
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Relationship between the unique microstructures and behaviors of high-entropy alloys 被引量:2
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作者 Yaqi Wu Peter KLiaw +5 位作者 Ruixuan Li Weiran Zhang Guihong Geng Xuehui Yan Guiqun Liu Yong Zhang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第6期1350-1363,共14页
High-entropy alloys(HEAs),which were introduced as a pioneering concept in 2004,have captured the keen interest of nu-merous researchers.Entropy,in this context,can be perceived as representing disorder and randomness... High-entropy alloys(HEAs),which were introduced as a pioneering concept in 2004,have captured the keen interest of nu-merous researchers.Entropy,in this context,can be perceived as representing disorder and randomness.By contrast,elemental composi-tions within alloy systems occupy specific structural sites in space,a concept referred to as structure.In accordance with Shannon entropy,structure is analogous to information.Generally,the arrangement of atoms within a material,termed its structure,plays a pivotal role in dictating its properties.In addition to expanding the array of options for alloy composites,HEAs afford ample opportunities for diverse structural designs.The profound influence of distinct structural features on the exceptional behaviors of alloys is underscored by numer-ous examples.These features include remarkably high fracture strength with excellent ductility,antiballistic capability,exceptional radi-ation resistance,and corrosion resistance.In this paper,we delve into various unique material structures and properties while elucidating the intricate relationship between structure and performance. 展开更多
关键词 high-entropy alloys unique microstructure special properties alloy design
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