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Growth morphology and evolution of quasicrystal in as-solidified Y-rich Mg-Zn-Y ternary alloys

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Rare Metals 2007年第5期26卷 435-439页

作者： wan diqing yang gencang CHEN Sulin ZHU Man ZHOU Yaohe State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi＇an 710072 China

A petal-like icosahedral quasicrystal with five branches,which is considered to be the representative morphology of the icosahedral quasicrystal,has been observed in the Y-rich Mg-Zn-Y ternary alloys. Moreover,the polygon-like morphology,another pattern of the icosahedral quasicrystal,has also been found in the Y-rich Mg-Zn-Y ternary alloys. The latter morphology results from the evolution of the former one. The growth mechanism of the petal-like morphology of the icosahedral quasicrystal was also discussed. Alloying composition,i.e.,Y element content,is a major factor inducing the morphology evolution of the icosahedral quasicrystal.

关键词： Mg-Zn-Y ternary alloys icosahedral quasicrystal morphology evolution Y element

Microstructure and growth morphology of Frank-Kasper phase in rapidly solidified Mg_(32)Al_(17)Zn_(32) ternary alloys

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Rare Metals 2009年第4期28卷 401-404页

作者： ZHU Man yang gencang wan diqing wanG Zhijun ZHOU Yaohe State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi＇an 710072 China

In the present investigation, the microstructures and growth morphology of Mg32（Al,Zn）49 Frank-Kasper phase in rapidly solidified Mg32Al17Zn32 temary alloys were studied in detail. The samples were characterised by X-ray diffraction analysis （XRD）, scanning electron microscopy （SEM）, field-emission scanning electron microscopy （FE-SEM） and energy dispersive spectrum （EDS）. The results show that the microstructures mainly consist of Mg3e（Al,Zn）49 Frank-Kasper phase and interdendritic Mg-rich O-phase. Under rapid solidification condition, Mg32（Al,Zn）49 Frank-Kasper phase reveals a perfect faceted dendritic characteristic in the shape of a three-fold symmetric microstructure with doublet tips in the axes direction. Observations for fracture surfaces show that the growth morphology of Mg32（Al,Zn）49 grains was truncated cubic, and its growth mechanism was also discussed.

关键词： Frank-Kasper phase rapid solidification faceted dendrite growth morphology

Microstructures and Morphology Evolution of Icosahedral Phase of As-cast Mg_(67.4)Zn_(28.9)Y_(3.7) Ternary Alloy Subjected to the Pouring Temperature

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Journal of Materials Science & Technology 2009年第4期25卷 445-448页

作者： Man Zhu gencang yang diqing wan Suling Cheng Yaohe Zhou State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi＇an 710072 China

The microstructure, chemical composition and morphology evolution of icosahedral quasicrystalline phase of Mg67.4Zn28.9Y3.7 ternary alloy were investigated in detail at different pouring temperatures by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and energy-dispersive spectrum （EDS）. Low interracial energy favors the formation of l-phase. The experimental results show that the primary l-phase reveals petal-shaped with five and six branches, where each branch has facetted growth morphology with the size ranging from 50 to 100μm. As the temperature decreases, the polygon-shaped l-phase forms, attributed to the decomposition of branch of petal-shaped l-phase, and then it grows bigger and some of the fine polygons join together to form large polygons. Besides these, （α-Mg＋l-phase） eutectic structures disappear and the relative amount of Mg7Zn3 phase increases as the pouring temperature decreases. The chemical composition and morphology evolution of l-phase were also discussed.

关键词： Icosahedral quasicrystal Mg-Zn-Y Morphology evolution Eutectic structures

Precipitation and responding damping behavior of heat-treated AZ31 magnesium alloy

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Acta Metallurgica Sinica(English Letters) 2009年第1期22卷 1-6页

作者： diqing wan Jincheng wanG Gaifang wanG Lin LIN Zhigang FENG gencang yang State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi＇an 710072China

Microstructure observation and dynamic mechanical analysis were carried out to investigate the precipitation and responding damping behaviors of AZ31 magnesium alloy. All the strain amplitude-dependent damping curves of the aged alloys are located between the curves of solutionized and as-cast alloys, although they have different critical strain amplitudes. The G-L theory is employed to explain the damping mechanism involving the interaction between the dislocation and the precipitated phase. In addition, a damping peak is observed at temperatures close to 330 ℃ for AZ31 magnesium alloy, which is related to the β-MglTA112 phase dissolution.

关键词： Magnesium alloys Damping behavior Precipitation G-L model Damping peak

Microstructure,Mechanical Properties and Damping of SiC/Mg97Zn1Y2 Composites

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Journal of Wuhan University of Technology(Materials Science) 2024年第6期39卷 1580-1585页

作者： wan diqing TANG Hao wanG Houbin wanG Yu yang Fan SUN Yumeng wanG Yongyong School of Materials Science and Engineering East China Jiaotong UniversityNanchang 330000China

SiC particles were added to the Mg97Zn1Y2 alloy to improve its mechanical properties and damping *** microstructure,mechanical properties,and strain amplitude dependence of high-damping and high-strength SiC/Mg97Zn1Y2 magnesium matrix composites were *** strain amplitude-dependent damping of SiC/Mg97Zn1Y2 composites and the effect of SiC on this property were discussed *** anelastic damping,the strain amplitude-dependent damping curves of the composites were mainly divided into two sections,dominated by the G-L *** the strain amplitude reaches a certain value,the dislocation motion inside the matrix becomes ***,the damping of the material could not be explained using the G-L model,and a new damping model related to microplastic deformation was *** the anelastic damping stage,with the increase in the amount of the added SiC particles,the damping performance first increases and then ***,the damping value of the composite material is larger than that of the matrix *** the microplastic deformation stage,the damping properties of the composites and matrix alloys considerably increase with the strain amplitude.

关键词： high damping high strength magnesium matrix composites strain amplitude

Characterization of a Mg_(95.5)Zn_(1.5)Y_(3)alloy both containing W phase and LPSO phase with or without heat treatment

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Journal of Magnesium and Alloys 2017年第2期5卷 217-224页

作者： Li Zhumin wan diqing Huang Yi Ye Shuting Hu Yinglin School of Materials Science and Engineering East China Jiaotong UniversityNanchang 330013China Materials Research Group Faculty of Engineering and the EnvironmentUniversity of SouthamptonSouthampton SO171 BJUK

The influence of solid solution treatment on the microstructure and corrosion resistance of as-cast Mg_(95.5)Zn_(1.5)Y_(3) alloy is *** microstructure of the as-cast Mg_(95.5)Zn_(1.5)Y_(3) alloy mainly consisted ofα-Mg,W(Mg_(3)Zn_(3)Y_(2))phase,and the long period stacking ordered(LPSO)(Mg_(12)ZnY)*** solid solution treatment,most of the W phase disappears gradually with increasing solution treatment time,with only a small amount of W phase distributed as *** LPSO phase slightly dissolved into substrate,and its morphology transitions from blocky shape to rod *** solution treatment of Mg_(95.5)Zn_(1.5)Y_(3) exhibits excellent corrosion resistance,because the Y and Zn atoms became enriched in the matrix and the changed morphologies of the LPSO and W phases were modified through heat *** alloy created with solid solution treatment at 520 ℃ for 10 hours exhibits corrosion potential of−1.419 V,suggesting a significant improvement in corrosion performance.

关键词： Magnesium alloys LPSO phase Solid solution treatment Corrosion resistance

Microstructure modification by La_2O_3 and its effect on wear resistance properties of as-cast ZL107 alloy

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Rare Metals 2010年第5期29卷 460-464页

作者： wan diqing Key Laboratory of the Ministry of Education of China for Conveyance and Equipment,East China Jiaotong University,Nanchang 330013,China Key Laboratory of the Ministry of Education of China for Conveyance and Equipment East China Jiaotong University Nanchang China

Modification of ZL107 aluminum alloy has been successfully achieved by using La2O3. The different casting parameters, including casting temperature as well as holding time and modifier content, were carried out to investigate the modification effects. The results show that the best modifier content is 1.0 wt.%, and the casting temperature has little effect. In addition, the wear behavior of modified and unmodified ZL 107 has been compared. The wear resistance of as-cast ZL 107 aluminum alloy can be significantly improved after modification.

关键词： aluminum alloys lanthanum oxides modification microstructure wear resistance

Mg-Zn-Y三元合金富Mg区凝固组织及二十面体准晶相形貌

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稀有金属材料与工程 2007年第12期36卷 2166-2168页

作者：万迪庆杨根仓周尧和西北工业大学凝固技术国家重点实验室陕西西安710072

通过常规凝固方法在Mg28Zn2Y三元合金中的富Mg区获得了二十面体稳定准晶相。Mg28Zn2Y三元合金铸态组织中存在α-Mg相,Mg7Zn3相和二十面体准晶相。该合金的准晶形貌有两种:一种为尺寸较大、具有五次对称性的花瓣状;另一种为尺寸稍小、对... 详细信息

通过常规凝固方法在Mg28Zn2Y三元合金中的富Mg区获得了二十面体稳定准晶相。Mg28Zn2Y三元合金铸态组织中存在α-Mg相,Mg7Zn3相和二十面体准晶相。该合金的准晶形貌有两种:一种为尺寸较大、具有五次对称性的花瓣状;另一种为尺寸稍小、对称性不太明显的团状。五次对称性的花瓣状形貌是二十面体准晶,是按其特有的五次对称轴的择优方向自由生长所致。冷却速率直接影响合金凝固过程中准晶熟化时间。熟化时间越长,越容易使准晶花瓣端部粗化以及在端部发生分叉。端部的分叉容易使得花瓣准晶破碎,破碎的准晶游离到低温相中,在界面能的作用下形成多边形形貌。

关键词： Mg-Zn-Y合金二十面体准晶形貌特征冷却速率

Mg-Zn-Y三元合金中二十面体准晶相生长形貌及其演化

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稀有金属材料与工程 2006年第9期35卷 1404-1407页

作者：万迪庆杨根仓朱满周尧和西北工业大学凝固技术国家重点实验室陕西西安710072

采用常规凝固方法在Mg-Zn-Y三元合金系中获得了大体积分数的二十面体准晶。二十面体准晶相有2种典型形貌特征:一种为花瓣状,另一种为多边形形状。这是准晶在生长过程中形貌演化的结果。合金的成分和冷却速率是影响准晶形貌的主要因素。... 详细信息

采用常规凝固方法在Mg-Zn-Y三元合金系中获得了大体积分数的二十面体准晶。二十面体准晶相有2种典型形貌特征:一种为花瓣状,另一种为多边形形状。这是准晶在生长过程中形貌演化的结果。合金的成分和冷却速率是影响准晶形貌的主要因素。准晶合金中生成的低温相越多,冷却速率越慢,准晶相生长的时间和空间条件越好,准晶相越容易由花瓣状演化成多边形状。准晶的形成有包晶反应参与,包晶反应是一种由初生固态相扩散控制的反应,因此,准晶在生长初期和最终形态其元素含量有明显差别,分析表明,准晶生长初期Mg元素含量偏低,Zn和Y元素含量偏高。

关键词： Mg-Zn-Y三元合金系二十面体准晶相形貌特征成分特征