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Mg-TM-RE系镁合金中LPSO相的研究进展
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作者 罗宇伦 杨鸿 +4 位作者 董志华 蒋斌 张双艳 张丁非 潘复生 《中国有色金属学报》 EI CAS CSCD 北大核心 2024年第5期1429-1452,共24页
镁合金是最具发展潜力的轻量化材料之一,但相对较低的强度和塑性限制了其工程应用。具有堆垛有序和化学有序特征的长周期堆垛有序(LPSO)相是有望实现镁合金强韧化的新型析出相,受到了越来越广泛的关注。本文总结分析了LPSO相的原子结构... 镁合金是最具发展潜力的轻量化材料之一,但相对较低的强度和塑性限制了其工程应用。具有堆垛有序和化学有序特征的长周期堆垛有序(LPSO)相是有望实现镁合金强韧化的新型析出相,受到了越来越广泛的关注。本文总结分析了LPSO相的原子结构特征、形成和转变机制,讨论了不同合金元素对LPSO相稳定性、本征结构物性参数的影响规律,分析了LPSO相对镁合金动态再结晶行为和力学性能的影响机理,并总结了基于LPSO相发展高性能镁合金需解决的关键问题,以期为新型高强韧镁合金的发展提供参考。 展开更多
关键词 镁合金 lpso 结构物性 动态再结晶 强韧化机制
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基于机器学习的含LPSO相镁合金腐蚀
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作者 裴三略 王海涛 +2 位作者 韩越兴 李谦 王敬丰 《中国有色金属学报》 EI CAS CSCD 北大核心 2024年第6期1964-1981,共18页
含LPSO相镁合金具备优异的综合力学性能,在轨道交通、航空航天、生物医疗等领域具有广泛的应用前景,然而其易腐蚀的特性极大制约了该类合金的广泛应用。本文聚焦机器学习辅助研究合金腐蚀这一新兴领域,首先重点概述了机器学习在合金腐... 含LPSO相镁合金具备优异的综合力学性能,在轨道交通、航空航天、生物医疗等领域具有广泛的应用前景,然而其易腐蚀的特性极大制约了该类合金的广泛应用。本文聚焦机器学习辅助研究合金腐蚀这一新兴领域,首先重点概述了机器学习在合金腐蚀研究等领域的应用进展,以期通过机器学习方法构建含LPSO相镁合金腐蚀预测模型,阐明LPSO相腐蚀机理;其次系统总结了镁合金中LPSO相含量、形状、结构、分布等显微组织对合金腐蚀性能的影响,为建立准确可靠的腐蚀模型提供借鉴与理论指导。最后,讨论了机器学习在含LPSO相镁合金腐蚀领域的发展机遇和挑战,展望了其发展前景。 展开更多
关键词 镁合金 lpso 腐蚀性能 机器学习 腐蚀预测
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LPSO相调控对ECAP挤压Mg-Y-Zn-Al合金组织和力学性能的影响
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作者 田丰 边丽萍 +2 位作者 孟棫朴 张红芳 梁伟 《热加工工艺》 北大核心 2024年第7期94-97,共4页
针对含18R-LPSO相铸态Mg-Y-Zn系合金塑韧性差、变形后力学性能提高有限的问题,研究了固溶、铸态+ECAP挤压和固溶+ECAP对Mg-3.74Y-1Zn-0.5Al(at%)合金力学性能的影响。结果表明,固溶处理诱发18R→14H-LPSO相转变、Al(Y,Zn)相化合物颗粒... 针对含18R-LPSO相铸态Mg-Y-Zn系合金塑韧性差、变形后力学性能提高有限的问题,研究了固溶、铸态+ECAP挤压和固溶+ECAP对Mg-3.74Y-1Zn-0.5Al(at%)合金力学性能的影响。结果表明,固溶处理诱发18R→14H-LPSO相转变、Al(Y,Zn)相化合物颗粒破碎细化,改善了合金的塑性,但强度几乎不变。铸态+ECAP挤压导致18R-LPSO和Al(Y,Zn)相破碎,并诱发大量α-Mg晶粒发生再结晶。固溶+ECAP挤压使14H-LPSO相弯曲或扭折变形、细小Al(Y,Zn)颗粒均匀分散,仅少数α-Mg晶粒发生再结晶,其强度、塑韧性远高于铸态+ECAP挤压合金的。良好强度、塑韧性匹配的14H-LPSO相的大量形成、α-Mg基体再结晶被抑制及细小Al(Y,Zn)颗粒的均匀分散是其性能提高的主要原因。 展开更多
关键词 Mg-Y-Zn-Al合金 lpso 等通道转角挤压(ECAP) 力学性能
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Formation and transformation of metastable LPSO building blocks clusters in Mg-Gd-Y-Zn-Zr alloys by spinodal decomposition and heterogeneous nucleation 被引量:1
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作者 Xin Zhao Zhong Yang +2 位作者 Jiachen Zhang Minxian Liang Liying Wang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第2期673-686,共14页
To study the formation and transformation mechanism of long-period stacked ordered(LPSO)structures,a systematic atomic scale analysis was conducted for the structural evolution of long-period stacked ordered(LPSO)stru... To study the formation and transformation mechanism of long-period stacked ordered(LPSO)structures,a systematic atomic scale analysis was conducted for the structural evolution of long-period stacked ordered(LPSO)structures in the Mg-Gd-Y-Zn-Zr alloy annealed at 300℃~500℃.Various types of metastable LPSO building block clusters were found to exist in alloy structures at different temperatures,which precipitate during the solidification and homogenization process.The stability of Zn/Y clusters is explained by the first principles of density functional theory.The LPSO structure is distinguished by the arrangement of its different Zn/Y enriched LPSO structural units,which comprises local fcc stacking sequences upon a tightly packed plane.The presence of solute atoms causes local lattice distortion,thereby enabling the rearrangement of Mg atoms in the different configurations in the local lattice,and local HCP-FCC transitions occur between Mg and Zn atoms occupying the nearest neighbor positions.This finding indicates that LPSO structures can generate necessary Schockley partial dislocations on specific slip surfaces,providing direct evidence of the transition from 18R to 14H.Growth of the LPSO,devoid of any defects and non-coherent interfaces,was observed separately from other precipitated phases.As a result,the precipitation sequence of LPSO in the solidification stage was as follows:Zn/Ycluster+Mg layers→various metastable LPSO building block clusters→18R/24R LPSO;whereas the precipitation sequence of LPSO during homogenization treatment was observed to be as follows:18R LPSO→various metastable LPSO building block clusters→14H LPSO.Of these,14H LPSO was found to be the most thermodynamically stable structure. 展开更多
关键词 lpso Spinodal decomposition Homogenization treatment CLUSTERS Phase transformation
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Microstructure and damping properties of LPSO phase dominant Mg-Ni-Y and Mg-Zn-Ni-Y alloys 被引量:1
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作者 Ruopeng Lu Kai Jiao +3 位作者 Nanting Li Hua Hou Jingfeng Wang Yuhong Zhao 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第3期1131-1153,共23页
This work studied the microstructure,mechanical properties and damping properties of Mg_(95.34)Ni_(2)Y_(2.66) and Mg_(95.34)Zn_(1)Ni_(1)Y_(2.66)alloys systematically.The difference in the evolution of the long-period ... This work studied the microstructure,mechanical properties and damping properties of Mg_(95.34)Ni_(2)Y_(2.66) and Mg_(95.34)Zn_(1)Ni_(1)Y_(2.66)alloys systematically.The difference in the evolution of the long-period stacked ordered(LPSO)phase in the two alloys during heat treatment was the focus.The morphology of the as-cast Mg_(95.34)Ni_(2)Y_(2.66)presented a disordered network.After heat treatment at 773 K for 2 hours,the eutectic phase was integrated into the matrix,and the LPSO phase maintained the 18R structure.As Zn partially replaced Ni,the crystal grains became rounded in the cast alloy,and lamellar LPSO phases and more solid solution atoms were contained in the matrix after heat treatment of the Mg_(95.34)Zn_(1)Ni_(1)Y_(2.66)alloy.Both Zn and the heat treatment had a significant effect on damping.Obvious dislocation internal friction peaks and grain boundary internal friction peaks were found after temperature-dependent damping of the Mg_(95.34)Ni_(2)Y_(2.66)and Mg_(95.34)Zn_(1)Ni_(1)Y_(2.66)alloys.After heat treatment,the dislocation peak was significantly increased,especially in the alloy Mg_(95.34)Ni_(2)Y_(2).66.The annealed Mg_(95.34)Ni_(2)Y_(2.66)alloy with a rod-shaped LPSO phase exhibited a good damping performance of 0.14 atε=10^(−3),which was due to the difference between the second phase and solid solution atom content.These factors also affected the dynamic modulus of the alloy.The results of this study will help in further development of high-damping magnesium alloys. 展开更多
关键词 Mg-Ni-Y alloys Mg-Zn-Ni-Y alloys lpso phase Heat treatment MICROSTRUCTURE Damping properties.
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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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基于PCC-LPSO-BP的油气管道缺陷分类识别研究
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作者 黄书童 贾晓丽 《石油矿场机械》 CAS 2024年第4期1-9,共9页
为准确识别油气管道的缺陷类型,分析缺陷漏磁信号特征对识别精度的影响,建立了基于PCC-LPSO-BP的油气管道缺陷识别模型。采用皮尔逊相关系数法(PCC)分析了缺陷漏磁信号特征量与缺陷尺寸间的相关程度,建立了混沌映射和莱维飞行改进的粒... 为准确识别油气管道的缺陷类型,分析缺陷漏磁信号特征对识别精度的影响,建立了基于PCC-LPSO-BP的油气管道缺陷识别模型。采用皮尔逊相关系数法(PCC)分析了缺陷漏磁信号特征量与缺陷尺寸间的相关程度,建立了混沌映射和莱维飞行改进的粒子群优化后的BP神经网络识别模型即LPSO-BP模型,采用评价指标综合比较了模型的识别效果,分析了该识别模型对各缺陷类型的识别精度以及各特征量对识别结果的影响。研究结果表明:LPSO-BP模型相较于BP模型识别精度提高了7.47%,且在现有的数据范围内对表面剥落和裂纹的识别率达到了100%。研究结果对油气管道缺陷识别量化具有一定的参考价值。 展开更多
关键词 漏磁信号 缺陷识别 皮尔逊相关系数 lpso-BP模型
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Deformation behavior of Mg-Y-Ni alloys containing different volume fraction of LPSO phase during tension and compression through in-situ synchrotron diffraction
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作者 S.Z.Wu Y.Q.Chi +4 位作者 G.Garces X.H.Zhou H.G.Brokmeier X.G.Qiao M.Y.Zheng 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第9期3631-3645,共15页
The deformation behavior of the as-extruded Mg-Y-Ni alloys with different volume fraction of long period stacking ordered(LPSO)phase during tension and compression was investigated by in-situ synchrotron diffraction.T... The deformation behavior of the as-extruded Mg-Y-Ni alloys with different volume fraction of long period stacking ordered(LPSO)phase during tension and compression was investigated by in-situ synchrotron diffraction.The micro-yielding,macro-yielding,tension-compression asymmetry and strain hardening behavior of the alloys were explored by combining with deformation mechanisms.The micro-yielding is dominated by basal slip of dynamic recrystallized(DRXed)grains in tension,while it is dominated by extension twinning of non-dynamic recrystallized(non-DRXed)grains in compression.At macro-yielding,the non-DRXed grains are still elastic deformed in tension and the basal slip of DRXed grains in compression are activated.Meanwhile,the LPSO phase still retains elastic deformation,but can bear more load,so the higher the volume fraction of hard LPSO phase,the higher the tensile/compressive macro-yield strength of the alloys.Benefiting from the low volume fraction of the non-DRXed grains and the delay effect of LPSO andγphases on extension twinning,the as-extruded alloys exhibit excellent tension-compression symmetry.When the volume fraction of LPSO phase reaches∼50%,tension-compression asymmetry is reversed,which is due to the fact that the LPSO phase is stronger in compression than in tension.The tensile strain hardening behavior is dominated by dislocation slip,while the dominate mechanism for compressive strain hardening changes from twinning in theα-Mg grains to kinking of the LPSO phase with increasing volume fraction of LPSO phase.The activation of kinking leads to the constant compressive strain hardening rate of∼2500 MPa,which is significantly higher than the tensile strain hardening rate. 展开更多
关键词 Mg-Y-Ni alloys lpso phase In-situ synchrotron diffraction Micro-yielding Tensile-compression asymmetry Strain hardening
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Achieving high strength and rapid degradation in Mg-Gd-Ni alloys by regulating LPSO phase morphology combined with extrusion
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作者 Kai Ma Jingfeng Wang +7 位作者 Yinhong Peng Chaoneng Dai Yuanlang Pan Ye Wang Danqian Wang Jinxing Wang Yanlong Ma Fusheng Pan 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第6期2312-2326,共15页
In this study,Mg-13.2Gd-4.3Ni alloys containing continuous bulk-shaped long-period stacking ordered(LPSO),lamellar LPSO,and a small amount of eutectic phase were prepared,and the evolution of microstructure at differe... In this study,Mg-13.2Gd-4.3Ni alloys containing continuous bulk-shaped long-period stacking ordered(LPSO),lamellar LPSO,and a small amount of eutectic phase were prepared,and the evolution of microstructure at different extrusion temperatures and its influence on mechanical and degradation properties as well as corrosion mechanism were investigated.Preheating before extrusion can effectively promote the precipitation of lamellar LPSO in matrix.EX400 with higher volume fraction of non-DRXed grains exhibited higher strength,which was mainly due to strong texture,high dislocation density,and high volume fraction of lamellar LPSO.The EX420 with higher volume fraction of DRXed grains showed higher degradation rate,which was mainly due to the higher density of grain boundary.The EX400 exhibited excellent comprehensive properties with tensile yield strength(TYS)of 334 MPa,ultimate tensile strength(UTS)of 484 MPa and elongation(EL)of 7.4%,ultimate compressive strength(UCS)of 638 MPa and compressive yield strength(CYS)of 443 MPa,degradation rate of 86.1 mg/cm^(2)/h at 93℃in 3 wt.%KCl solution. 展开更多
关键词 Mg-Gd-Ni alloys lpso Mechanical properties Degradation rate
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TiO_(2)@C catalyzed hydrogen storage performance of Mg-Ni-Y alloy with LPSO and ternary eutectic structure
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作者 Wenjie Song Wenhao Ma +5 位作者 Shuai He Wei Chen Jianghua Shen Dalin Sun Qiuming Wei Xuebin Yu 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第2期767-778,共12页
A designed Mg_(88.7)Ni_(6.3)Y_(5)hydrogen storage alloy containing 14H type LPSO(long-period stacking ordered)and ternary eutectic structure was prepared by regulating the alloy composition and casting.The hydrogen st... A designed Mg_(88.7)Ni_(6.3)Y_(5)hydrogen storage alloy containing 14H type LPSO(long-period stacking ordered)and ternary eutectic structure was prepared by regulating the alloy composition and casting.The hydrogen storage performance of the alloy was improved by adding nano-flower-like TiO_(2)@C catalyst.The decomposition of the LPSO structure during hydrogenation led to the formation of plenty of nanocrystals which provided abundant interphase boundaries and activation sites.The nanoscale TiO_(2)@C catalyst was uniformly dispersed on the surface of alloy particles,and the"hydrogen overflow''effect of TiO_(2)@C accelerated the dissociation and diffusion of hydrogen on the surface of the alloy particles.As a result,the in-situ endogenous nanocrystals of the LPSO structure decomposition and the externally added flower-like TiO_(2)@C catalyst uniformly dispersed on the surface of the nanoparticles played a synergistic catalytic role in improving the hydrogen storage performance of the Mg-based alloy.With the addition of the TiO_(2)@C catalyst,the beginning hydrogen desorption temperature was reduced to 200℃.Furthermore,the saturated hydrogen absorption capacity of the sample was 5.32 wt.%,and it reached 4.25 wt.%H_(2) in 1 min at 200℃and 30 bar. 展开更多
关键词 Hydrogen storage Mg lpso TiO_(2)@C Synergistic catalysis
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基于LPSO-GRNN模型的螺栓松紧状态预测研究
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作者 梁伟 陈志雄 +4 位作者 欧阳忠杰 龚晟炜 钟建华 钟舜聪 廖华忠 《机电工程》 CAS 北大核心 2023年第11期1814-1822,共9页
在轴重式动态汽车衡的服役状态下,由于受到重型货车频繁的加卸载循环冲击,会导致其内部螺栓发生松弛脱落,针对这一问题,提出了一种基于莱维飞行改进粒子群算法优化的广义回归神经网络(LPSO-GRNN)的轴重式动态汽车衡螺栓松紧状态预测模型... 在轴重式动态汽车衡的服役状态下,由于受到重型货车频繁的加卸载循环冲击,会导致其内部螺栓发生松弛脱落,针对这一问题,提出了一种基于莱维飞行改进粒子群算法优化的广义回归神经网络(LPSO-GRNN)的轴重式动态汽车衡螺栓松紧状态预测模型,并结合振动信号特征提取,将该模型应用于汽车衡螺栓松紧状态的预测。首先,研究并提取了螺栓不同松紧状态下输出振动信号的波形指标、峰值指标、脉冲指标、峭度指标等信号特征,并将其作为模型的共同输入特征向量;然后,采用莱维飞行提高了粒子群优化算法的寻优能力,通过产生随机步长,提高了算法的全局寻优能力,避免算法陷入局部最优值;利用改进的算法对广义回归神经网络(GRNN)的光滑因子进行了优化,得到了全局最优的光滑因子;最后,通过设计实验,分别使用广义回归神经网络(GRNN)、粒子群算法优化广义回归神经网络(PSO-GRNN)和LPSO-GRNN,以此来对螺栓松紧状态进行了预测,并将预测结果与实际情况进行了对比分析。实验结果表明:基于LPSO-GRNN建立的螺栓松紧状态预测模型,其预测准确率可达到95%。研究结果表明:该螺栓松紧状态预测模型可以有效提高汽车衡螺栓松紧预测的准确率,同时有效解决粒子群算法容易陷入局部最优收敛的问题。 展开更多
关键词 轴重式动态汽车衡 lpso-GRNN预测模型 螺栓紧固 振动信号特征提取 广义回归神经网络 粒子群算法优化 莱维飞行
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调控LPSO层片相Mg-9Gd-4Y-2Zn-0.5Zr合金的热变形行为及热塑性提升机制 被引量:2
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作者 田学栋 赵熹 +3 位作者 任贤魏 王思琪 张治民 郭拉凤 《塑性工程学报》 CAS CSCD 北大核心 2023年第3期131-142,共12页
以挤压态Mg-9Gd-4Y-2Zn-0.5Zr合金为研究对象,通过热处理调控出晶内不含和含层片状LPSO相的两种合金,进行了热压缩试验。结果表明,含层片状LPSO相合金热塑性更好,主要是由于层片状LPSO相的扭折及其诱发的连续动态再结晶能有效提升合金... 以挤压态Mg-9Gd-4Y-2Zn-0.5Zr合金为研究对象,通过热处理调控出晶内不含和含层片状LPSO相的两种合金,进行了热压缩试验。结果表明,含层片状LPSO相合金热塑性更好,主要是由于层片状LPSO相的扭折及其诱发的连续动态再结晶能有效提升合金的变形协调能力。随后,对含层片状LPSO相合金的热变形行为进行了深入研究,发现在低应变速率变形时,软化机制主要以不连续动态再结晶为主。在高应变速率变形时,动态回复和不连续动态再结晶共同作用,造成材料软化。结合应变0.8下的热加工图和典型区域微观组织分析,确定最佳成形温度为440~480℃,应变速率为0.001~0.01 s-1。提出了一种通过调控层片状LPSO相提升稀土镁合金热塑性的方法,为挤压态稀土镁合金的后续变形提供了新思路。 展开更多
关键词 稀土镁合金 热压缩 本构方程 lpso 动态再结晶
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18R-LPSO相的体积分数对Mg-Zn-Y合金腐蚀行为与机理的影响 被引量:3
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作者 席国强 牟宇 +4 位作者 麻彦龙 赵旭晗 熊菊 马凯 王敬丰 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2023年第2期454-466,共13页
通过实验设计阐明LPSO相对镁合金腐蚀行为的影响。按照形成18R-LPSO相的最小结构单元,即Zn/Y=3/4(摩尔比),设计4种不同LPSO相体积分数的Mg-Zn-Y合金,对比研究4种合金的显微组织和腐蚀行为。结果表明,合金主要含有α-Mg和18R-LPSO相,18R-... 通过实验设计阐明LPSO相对镁合金腐蚀行为的影响。按照形成18R-LPSO相的最小结构单元,即Zn/Y=3/4(摩尔比),设计4种不同LPSO相体积分数的Mg-Zn-Y合金,对比研究4种合金的显微组织和腐蚀行为。结果表明,合金主要含有α-Mg和18R-LPSO相,18R-LPSO相的体积分数随着Zn和Y含量的增加而增加。4种合金中18R-LPSO相的体积分数依次为16.55%、34.45%、54.24%和70.36%,18R-LPSO相的空间分布也由离散块状变为连续网络状。当LPSO相的体积分数在50%左右时,合金的耐蚀性最好,体积分数大于或小于50%都会导致合金耐蚀性能降低。 展开更多
关键词 MG-ZN-Y合金 18R-lpso 体积分数 耐腐蚀性能
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超声振动对含LPSO结构的Mg_(98)Y_(1.0)Ni_(0.5)Al_(0.5)合金显微组织与力学性能的影响
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作者 吕书林 赵第甲 +1 位作者 计效园 郭威 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2023年第1期59-66,共8页
低Y、Ni含量的LPSO结构增强镁合金具有低成本、优异力学性能的特点。为进一步提升其综合力学性能,掺杂Al元素及熔体超声振动处理是可行的途径。通过扫描电子显微镜、能谱分析、透射电子显微镜、X射线衍射和纳米压痕测试研究掺杂Al元素后... 低Y、Ni含量的LPSO结构增强镁合金具有低成本、优异力学性能的特点。为进一步提升其综合力学性能,掺杂Al元素及熔体超声振动处理是可行的途径。通过扫描电子显微镜、能谱分析、透射电子显微镜、X射线衍射和纳米压痕测试研究掺杂Al元素后低Y、Ni含量的Mg_(98)Y_(1.0)Ni_(0.5)Al_(0.5)合金的显微组织,对比超声振动对显微组织与力学性能的影响。掺杂Al后LPSO结构的含量降低,且在块状LPSO结构相邻处析出圆整的Al_(2)NiY相。Al_(2)NiY相与LPSO结构和Mg基体在界面处均不共格。通过对熔体施加超声振动处理后,Al_(2)NiY相被有效细化为短片状,并均匀分布在基体中,阻碍微裂纹的产生和扩展,从而提高Mg98Ni0.5Y1.0Al0.5合金的力学性能。与未经超声处理Mg_(98)Ni_(0.5)Y_(1.0)Al_(0.5)合金相比,其极限抗拉强度和伸长率提升至187 MPa和7.9%,分别增长21.4%和105.7%。 展开更多
关键词 Mg-Y-Ni-Al合金 lpso结构 超声振动 显微组织 力学性能
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Dissolution and reprecipitation of 14H-LPSO structure accompanied by dynamic recrystallization in hot-extruded Mg_(89)Y_(4)Zn_(2)Li_(5) alloy 被引量:3
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作者 Wei Liu Yu Su +3 位作者 Yuntao Zhang Liwen Chen Hua Hou Yuhong Zhao 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第4期1408-1421,共14页
We investigate the variation induced in long-period stacking ordered(LPSO)structures,dynamic recrystallization(DRX),and mechanical performance of hot-extruded Mg89Y4Zn2Li5 alloys fabricated at different extrusion spee... We investigate the variation induced in long-period stacking ordered(LPSO)structures,dynamic recrystallization(DRX),and mechanical performance of hot-extruded Mg89Y4Zn2Li5 alloys fabricated at different extrusion speeds(Ve=0.4,0.8,1.0,1.2 mm/s)and die angles(α=30°,60°,90°)under 400℃,the dissolution and reprecipitation of 14H LPSO structure accompanied by DRX process are then clarified in detail.Upon all extrusion conditions,the block 18R LPSO structures elongate in the extrusion direction,while the lamellar 14H LPSO structures dissolve under the deformation strain.In addition,due to discontinuous and continuous DRX mechanisms,all hot-extruded alloys have a full DRX microstructure consisting of equiaxed recrystallized grains,but the DRX grain size reduces when both extrusion speed and die angle decrease.Note that,in the interior of DRX grains,thin LPSO lamellae mixing 14H,18R and 24R structures nucleate and dynamically precipitate due to the dissolution of the original lamellar 14H LPSO structures.Furthermore,the hot-extruded Mg_(89)Y_(4)Zn_(2)Li_(5)alloy becomes stronger as decreasing of the extrusion speed and die angle,whereas the ductility remains nearly constant.Finally,the hotextruded Mg_(89)Y_(4)Zn_(2)Li_(5)alloy achieves an excellent strength-ductility balance at a relatively low extrusion speed(0.4 mm/s)and small die angle(30°)mainly due to the elongated 18R LPSO structure,fine and full DRX microstructure,thin mixed LPSO precipitates in the DRX grains,twins and dislocations. 展开更多
关键词 Magnesium Extrusion lpso RECRYSTALLIZATION Precipitation
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Synergetic deformation mechanisms in an Mg-Zn-Y-Zr alloy with intragranular LPSO structures 被引量:1
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作者 Z.Z.Peng X.H.Shao +3 位作者 Z.M.Liang D.L.Wang L.W.Wang X.L.Ma 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第5期1754-1768,共15页
Deformation kink is one of the important strengthening mechanisms of the long-period-stacking-ordered(LPSO)phase containing magnesium(Mg)alloys,while the deformation twin is generally suppressed.To optimize the mechan... Deformation kink is one of the important strengthening mechanisms of the long-period-stacking-ordered(LPSO)phase containing magnesium(Mg)alloys,while the deformation twin is generally suppressed.To optimize the mechanical properties of LPSO containing Mg alloy by simultaneously exciting kink and twin,we successfully prepared the Mg-Zn-Y-Zr alloy featuring intragranular LPSO phase and free grain boundary LPSO phase by homogenization.We unraveled the corresponding strengthening and toughening mechanisms through transmission electron microscopy characterization and theoretical analysis.The high strength and good plasticity of the homogenized alloy benefit from the synergistic deformation mechanism of multiple kinking and twining in the grains.And the activation of kinking and twinning depends on the thicknesses of LPSO lamellae and their relative spacing.These results may shed light on optimizing the design of Mg alloys regulating the microstructure of LPSO phases. 展开更多
关键词 Mg alloy lpso distribution KINK TWIN Transmission electron microscopy
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Controlling dynamic recrystallization via modified LPSO phase morphology and distribution in Mg-Gd-Y-Zn-Zr alloy 被引量:1
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作者 Ce Zheng Shuaifeng Chen +3 位作者 Ming Cheng Shihong Zhang Yingju Li Yuansheng Yang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第11期4218-4234,共17页
Featured initial microstructures of Mg-11Gd-4Y-2Zn-0.5Zr alloy(wt%) were obtained by adjusting temperatures of solid solution and cooling methods, including island intergranular 18R and 14H LPSO phases with low-densit... Featured initial microstructures of Mg-11Gd-4Y-2Zn-0.5Zr alloy(wt%) were obtained by adjusting temperatures of solid solution and cooling methods, including island intergranular 18R and 14H LPSO phases with low-density stacking faults, differentially spaced lamellar intragranular 14H-LPSO phases, and network intergranular 18R-LPSO phases with high-density intragranular stacking faults. Effects of these featured LPSO phases and stacking faults on dynamic recrystallization(DRX) behavior were investigated via hot compression. Promoted DRX behavior via particle stimulated nucleation(PSN) is introduced by coexisting intergranular island 18R and 14H LPSO phases and intragranular wide spacing lamellar 14H-LPSO phases, contributing the highest DRX fraction of 42.6%. Conversely, it is found that DRX behavior with network intergranular 18R-LPSO phases and dense intragranular stacking fault is considerably inhibited with the lowest fraction of 22.8%. That is, the restricted DRX due to dislocations pinning by stacking faults overwhelms the enhanced DRX behavior via PSN of island intergranular 18R and 14H LPSO phases. Specially, compared with dense intragranular lamellar 14H-LPSO phases, high-density stacking faults exert a larger inhibition effect on DRX behavior. 展开更多
关键词 Mg-Gd-Y-Zn-Zr Dynamic recrystallization lpso phases Particle stimulated nucleation Stacking fault
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Precipitation behavior of 14H LPSO structure in single 18R phase Mg-Y-Zn alloy during annealing at 773K 被引量:3
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作者 刘欢 严凯 +4 位作者 晏井利 薛烽 孙甲鹏 江静华 马爱斌 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第1期63-72,共10页
The microstructural evolution of a 18R single phase (S 18) alloy during annealing at 773 K for 100 h was investigated in order to reveal the formation mechanism of 14H phase. The results showed that the as-cast S 18... The microstructural evolution of a 18R single phase (S 18) alloy during annealing at 773 K for 100 h was investigated in order to reveal the formation mechanism of 14H phase. The results showed that the as-cast S 18 alloy was composed of 18R phase (its volume fraction exceeds 93%), W particles and α-Mg phase. The 18R phase in S18 alloy was thermally stable and was not transformed into 14H long period stacking ordered (LPSO) phase during annealing. However, 14H lamellas formed within tiny α-Mg slices, and their average size and volume fraction increased with prolonging annealing time. Moreover, the 14H phase is nucleated within α-Mg independently on the basis of basal stacking faults (SFs). The broadening growth of 14H lamellas is an interface-controlled process which involves ledges on basal planes, while the lengthening growth is a diffusion-controlled process and is associated with diffusion of solute atoms. The formation mechanism of 14H phase in this alloy could be explained as α-Mg'→α-Mg+14H. 展开更多
关键词 Mg-Y-Zn alloy 18R lpso phase 14H lpso phase high-temperature annealing microstructure evolution
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长周期有序堆垛相(LPSO)的研究现状及在镁合金中的作用 被引量:14
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作者 李响 毛萍莉 +3 位作者 王峰 王志 刘正 周乐 《材料导报》 EI CAS CSCD 北大核心 2019年第7期1182-1189,共8页
镁合金由于具有较高的比强度、比刚度以及良好的成形性和切屑加工性等优点,在航空航天、交通以及电子产品等领域获得了广泛的应用。但是由于镁合金的绝对强度较低,使其在结构件的应用上受到了一定的限制。近年来,采用稀土元素来提高镁... 镁合金由于具有较高的比强度、比刚度以及良好的成形性和切屑加工性等优点,在航空航天、交通以及电子产品等领域获得了广泛的应用。但是由于镁合金的绝对强度较低,使其在结构件的应用上受到了一定的限制。近年来,采用稀土元素来提高镁合金的强度已成为镁合金研究领域的热点,尤其是Mg-Zn-Y镁合金。由于m(Y)/m(Zn)比的变化,Mg-Zn-Y中的强化相也逐渐产生变化,当m(Y)/m(Zn)>1时,在Mg-Zn-Y合金中出现与镁合金基体完全共格、但富含Y、Zn元素的结构及化学成分均有序的长周期堆垛有序相(LPSO)。相比于其他第二相,LPSO相具有高硬度、良好的热稳定性、良好的阻尼性能、高抗蠕变性能、高弹性模量等特点,因此,这种新型结构强化相在镁合金中对其力学性能的影响引起了研究人员的广泛关注,成为目前镁合金强韧化的研究热点。近几年的研究多是通过快速凝固粉末冶金、铜模铸造、溶体甩带等不同的铸造方法制备出含LPSO相的镁合金,并通过改变溶质原子种类、含量及比例的方法来探究LPSO相对镁合金性能的影响,之后通过热处理、挤压和轧制等加工工艺对LPSO相的数量、尺寸和分布进行调控,进而提高镁合金的性能。而有关LPSO相的微观结构,如LPSO相结构中各原子的排列方式和具体位置等,通过第一性原理计算模拟、选区电子衍射(SADP)、高分辨率透射(HRTEM)及高角环形暗场像扫描电子显微镜(HAADF-STEM)等方法进行研究,已经建立了一个比较完善的LPSO相结构模型。同时,近几年对镁合金凝固和变形过程LPSO相结构中原子的运动研究也有了突破性的进展。在21世纪初,有研究人员通过快速凝固和热挤压的方法制备出的Mg97Zn1Y2(原子分数)合金的屈服强度和延伸率分别达到了610 MPa和5%,这些优异的力学性能归因于纳米级的LPSO相。本文综述了镁合金中LPSO相的形成机制、类型及其含LPSO相的合金体系,并对LPSO相的结构堆垛有序和化学成分有序进行了详尽的叙述,同时分析了LPSO相提高镁合金强度、塑性、抗蠕变性及高阻尼性能的机理;阐述了含LPSO相镁合金的制备工艺对其性能产生的影响;最后对含LPSO相镁合金的发展方向进行了展望。 展开更多
关键词 镁合金 lpso 力学性能 强韧化机理
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Mg_(97)ZnY_2合金中LPSO结构的研究现状 被引量:7
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作者 高岩 王渠东 +2 位作者 赵阳 童炎 郑江 《材料导报》 EI CAS CSCD 北大核心 2008年第1期94-97,共4页
综述了国内外几种制备Mg_(97)ZnY_2合金的工艺特点和研究现状,分析了该合金中几种不同长周期结构(Long period stacking ordered structure,简称LPSO)的形成机制及堆跺方式,提出了Mg_(97)ZnY_2合金当前研究的主要问题,并展望了Mg_(97)Zn... 综述了国内外几种制备Mg_(97)ZnY_2合金的工艺特点和研究现状,分析了该合金中几种不同长周期结构(Long period stacking ordered structure,简称LPSO)的形成机制及堆跺方式,提出了Mg_(97)ZnY_2合金当前研究的主要问题,并展望了Mg_(97)ZnY_2合金应用于现实生产的前景。 展开更多
关键词 Mg97ZnY2合金 lpso结构 快速凝固 堆跺
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