Z.K. Li 1
,
2)
,
L.Zhou 1
,
2)
,
J.Z. Liu 1)
,
P.Z. Li 1) and W.J. Zhao 3) 1) Northwest Institute for Nonferrous Metal Research
,
Xi'an 710016
,
China 2) Xi'an Jiaotong University
,
Xi'an 710049
,
China 3) Nuclear Power Institute of China
,
Chengdu 610041
,
China M
金属学报(英文版)
he out of pile corrosion resistance of new Zirconium alloys in 500℃/10 3MPa steam has been investigated and the effect of alloying elements, Sn,Nb,Fe,Cr on the property has been analyzed. The results show that the new alloys have better corrosion resistance than Zircaloy 4. That no nodular corrosion is found during test cycles shows the nodular corrosion resistance can be dramatically improved by addition of alloying elements Nb. The Fe/Cr ratio should be properly controlled if there is Cr addition in the alloys when developing new alloys.
关键词:
zirconium alloy
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null
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null
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null
尹奇异
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袁硕果
,
陈才
,
田长安
,
张凌云
机械工程材料
采用传统的陶瓷制备技术制备了0.95K0.47Na0.47Li0.06NbO3-0.05BaxSr1-xTiO3体系元铅压电陶瓷,研究了该体系陶瓷的微观结构与压电、介电性能.结果表明:在1 165℃烧结4 h的条件下,该体系陶瓷能形成单一的钙钛矿型结构;随着x值的增大,陶瓷的压电、介电性能先增后降,并在x为0.85时性能达到最佳,其压电常数为136 pC/N,机电耦合系数为39%,机械品质因数为146,介电常数为1 327,介质损耗为0.021.
关键词:
无铅压电陶瓷
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微观结构
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铌酸钾钠锂
刘利华
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江向平
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江福兰
,
郑严艳
稀有金属材料与工程
采用传统固相法对(1-x)K0.44Na0.52Li0.04Nb0.86Ta0.10Sb0.04O3-xSrTiO3压电陶瓷进行了钛酸锶掺杂改性研究.使用XRD并结合常规压电陶瓷性能测试手段对该体系的显微结构、压电、介电性能等进行表征.研究结果表明,随着SrTiO3加入量的增大,材料的居里温度和压电性能逐渐下降,材料的介电温度峰形逐渐变宽,出现弛豫现象;陶瓷烧结性能改善.致密度增加.
关键词:
无铅压电陶瓷
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压电性能
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介电性能
杨志怀
,
张云鹏
,
张美光
,
许强
,
张亚妮
,
张蓉
无机材料学报
doi:10.15541/jim20150030
采用基于密度泛函理论(DFT)的平面波超软赝势方法，计算了 CoCr2O4及 Li、Na、K 和 Rb 四面体掺杂CoCr2O4的基态结构、电子结构和光学性质。计算结果表明：一价离子四面体掺杂都导致晶格有微小的畸变，使体系的稳定性降低， Rb掺杂的体系最稳定；电子态密度的计算结果表明：掺杂体系的导带主要有Co-3d和Cr-3d轨道电子构成，掺杂离子改变了CoCr2O4导带的电子结构，主要引起了导带Co-3d态密度峰的下移，随着掺杂浓度的增大，费米能级进入价带更深；光学性质计算表明：掺杂体系的吸收光谱发生红移，并在低能区有很强的吸收，表明掺杂能极大地提高CoCr2O4对可见光的吸收和光催化效率。
关键词:
尖晶石结构CoCr2O4
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密度泛函理论
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电子结构
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光学性质
贾玉鑫
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黄金亮
,
冯剑
材料热处理学报
采用Gleeble-1500D热模拟机对Mg-8Li-2Al-1Zn合金进行热压缩实验,研究了变形温度为523 ～ 723 K、应变速率为0.01 ～10 s-1条件下的合金热变形行为,并建立了合金的流变应力本构方程及热加工图.结果表明:Mg-8Li-2Al-1Zn合金的流变曲线均属于动态再结晶型,流变应力随着温度升高(应变速率降低)而减小.显微组织的变化验证了动态回复和动态再结晶的发生.Mg-8Li-2Al-1Zn合金流变应力本构关系可以用双曲正弦函数和Z参数准确的描述,平均应力指数为4.62,平均热激活能为139.35 J/mol.根据建立的加工图,预测合金热变形的最佳工艺参数为:523 ～573 K,0.1～1 s-1.
关键词:
镁锂合金
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热变形
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动态再结晶
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本构方程
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微观组织
Journal of Physics-Condensed Matter
Based on ab initio total energy calculations, Li, Na and Ag interstitials are found to be stable with at least a 1.56 eV energy barrier to transform to a zinc substitutional site in ZnO, whereas K interstitial has a relatively small energy barrier at 0.79 eV. The isolated dopant substitutional defects (LiZn, NaZn, KZn and AgZn) are found to be rather stable, with at least a 3.4 eV energy barrier to transform to an interstitial site. All of the dopant interstitials (Lii, Nai, Ki and Agi) are fast diffusers. The diffusion of Li interstitial is isotropic, whereas the diffusion of Na, K and Ag interstitials is highly anisotropic. Fundamental processes of the vacancy-assisted mechanisms are systematically investigated and specific values of the energy barriers are obtained.
关键词:
augmented-wave method
张立春
,
何安强
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叶恒强
,
张永昌
材料研究学报
用HRTEM、TEM及EDAX分析研究了Al─Li—Cu—Mg—Zr合金中的一种新相(暂名H相)和六角Z相的结构,确定H相具有四方点阵,点阵参数为α=2.8nm,c=2.4nm,EDAX分析表明H相和Z相均含Al、Mg、Cu发现H相与Z相的共存取向关系为[100]‖[1120]Z,[1010]H‖[0001]Z。还观察到Z相中一种特有的旋转畴结构
关键词:
Al─Li─Cu─Mg─Zr合金.四方H相
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tetragonal H phase
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hexagonal Z phase
张立春
,
何安强
,
吴玉琨
,
叶恒强
,
张永昌
金属学报
利用高分辨电镜(HRTEM)和常规电子显微术研究了快速凝固Al-Li-Cu—Mg—Zr合金中Z相和T相的结构关系,发现两相间两种确定的晶体学取向关系,并以此为依据解释了Z相和T相的某些结构缺陷两相的结构有密切关联,其中一相中缺陷的扩展会导致另一相的形成
关键词:
Al-Li-Cu-Mg-Zr合金
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Z hexagonal phase
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T f.c.c. phase
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shear structure
High Temperature Materials and Processes
In order to decrease the solubility of NiO cathode of molten carbonate fuel cell (MCFC) and develop materials and coatings for separators in the cathode side of MCFC, dysprosium was introduced to modify nickel. In present paper, binary Ni-Dy alloys containing 1, 3 and 5 mass%Dy respectively were prepared. The alloys are two-phase composed of a nickel solid solution and an intermetallic phase Ni17Dy2. The oxidation behavior of the alloys at 923-1023K in air was evaluated by thermogravimetric tests coupled with some physical analysis techniques. The samples pre-oxidized at 923K for 100h were then immersed in molten (0.62Li,0.38K)(2)CO3 at 923K to examine the effect of Dy on the lithiation of NiO in the melt. The results indicated that the addition of dysprosium to nickel increased its oxidation rate, except for Ni-1Dy at 1023K. The scales formed on the alloys were composed of NiO with a trace of DY2O3. The lithiation of NiO in molten (Li,K)(2)CO3 could be favored by the addition of dysprosium. For comparison, binary Ni-Y alloys were also examined. The effect of yttrium on the air oxidation and molten (Li,K)(2)CO3 corrosion of nickel was similar to dysprosium, except that the Y-containing precipitates in Ni-Y alloys underwent very fast preferential corrosion while the Dy-containing intermetallic phases in Ni-Dy alloys not.
关键词:
molten carbonate fuel cell;Ni-Dy alloys;oxidation;molten carbonates;lithiation;fe-20cr alloys;behavior;600-800-degrees-c;coatings
钟耀东
,
李志同
,
郭远刚
,
周权
,
周凤瑞
,
强颖怀
,
杨凌玲
,
霍瑛
,
赵思茜
材料科学与工程学报
富锂锰过渡金属层状正极材料以其成本低、安全、容量高受到广泛关注,X射线衍射（XRD）和电化学性能测试显示以共沉淀结合煅烧成功合成富锂层状正极材料zLi2MnO3.（1-z）LiMn0.4Ni0.4Co0.2O2（z=0.2,0.4,0.6）。其中z=0.4组分的放电容量达到210mAh/g（2-4.8V,0.05C）,远高于z=0.6组分,而经20个充放电循环的稳定性也优于z=0.2组分。微分容量分析表明z=0.2组分中因Ni/（Co＋Mn）比值较大和Li2MnO3含量较少可能导致其容量逐渐衰减。z=0.6则因所含LiMn0.4Ni0.4Co0.2O2量较少,造成其放电容量较低;z=0.4拥有最佳Li2MnO3及LiMn0.4Ni0.4Co0.2O2组合使其容量和循环性能最好。
关键词:
zLi2MnO3·(1-z)LiMn0.4Ni0.4Co0.2O2
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正极材料
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循环性能
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容量
