材料期刊网

固体氧化物电化学装置用高温 SiO2-Al2O3-BaO-MgO 和SiO2-Al2O3-ZrO2-CaO-Na2O 玻璃陶瓷密封剂

S. QI , N. M. POROTNIKOVA , M. V. ANANYEV , A. V. KUZMIN , V. A. EREMIN , A. A. PANKRATOV , N. G. MOLCHANOVA , O. G. REZNITSKIKH , A. S. FARLENKOV , E. G. VOVKOTRUB , Yu. P. ZAIKOV

中国有色金属学报(英文版) doi:10.1016/S1003-6326(16)64421-7

制备了在燃料电池中作为密封剂使用的操作温度可达700~900°C 的 SiO2?Al2O3?BaO?MgO 和SiO2?Al2O3?ZrO2?CaO?Na2O 系玻璃陶瓷。采用同步热分析和高温膨胀测量技术，对所研究的玻璃陶瓷的热性能和其与燃料电池用材料(YSZ 电解质，合金连接器 Crofer22APU,15Х25Т)的匹配性能进行研究。采用原子发射光谱对玻璃陶瓷的元素成分进行分析。结果表明，45%SiO2?15%Al2O3?25%BaO?15%MgO 陶瓷的线膨胀系数为10.0×10?6°C?1，60%SiO2?10%Al2O3?10%ZrO2?5%CaO?15%Na2O 的为9.5×10?6°C ?1。采用扫描电镜对 YSZ/玻璃陶瓷/Crofer22APU 的界面结构进行分析。SiO2?Al2O3?BaO?MgO 玻璃中的硅酸盐相发生了晶化，采用拉曼光谱和X 射线衍射对晶化产物进行了分析。与非晶玻璃相比，所研究的玻璃陶瓷作为电化学或氧传感器中的密封剂使用时具有更佳的性能指标。而 SiO2?Al2O3?ZrO2?CaO?Na2O 低温非晶陶瓷可以作为燃料电池中的密封剂使用。

关键词: 玻璃陶瓷密封剂 , 燃料电池 , YSZ , Crofer22APU , 硅酸镁

原生QI成核中间相炭微球的结构

王成扬 , 姜卉 , 李鹏 , 郑嘉明

新型炭材料 doi:10.3969/j.issn.1007-8827.2000.04.003

以含有原生QI的煤沥青为原料,采用热缩聚方法制备出中间相炭微球.用扫描电子显微镜(SEM)观察了中间相炭微球的形貌和断面结构.经初步判断,在实验条件下原生QI成核煤沥青基中间相炭微球更倾向于"地球仪" 型结构.并对以QI为核形成中间相微球的过程进行了分析.

关键词: 原生喹啉不溶物 , 中间相炭微球 , 结构

煤沥青原料中QI含量对中间相有序生长的影响

黄爱华 , 金鸣林 , 李和兴 , 房永征

材料导报

试验是以2种含不同QI的煤沥青为原料,采用变径反应管进行热转化反应制备有序性中间相的研究.试验采用偏光显微镜和扫描电镜(SEM)观察了原料各反应阶段的微观结构,考察了QI对热转化过程中中间相有序生长的影响,分析了热转化过程中软化点及族组分的变化.结果表明:少量的喹啉不溶物含量不会阻碍中间相有序的发展.高QI(2.03%)原料易生成镶嵌结构的中间相体,高温处理后样品呈轴状、短纤维、层片松散的石墨化焦结构;含低QI(0.11%)的原料能生成较好的、大区域的中间相体,域结构的中间相体在外力导向和内部裂解气流的作用下容易生成有序的半焦,高温处理后呈大区域、片层紧密、有序性强的细纤维焦结构.同时研究发现,在热转化过程中可通过测定软化点(SP)和TI含量来确定中间相转化程度.软化点约低于250℃、TI为75%左右时为初始中间相区域体形成阶段、半焦生成的前期.

关键词: 煤沥青 , 热转化反应 , 喹啉不溶物 , 中间相

FORMATION OF AMORPHOUS GE-S SEMICONDUCTOR ALLOYS BY MECHANICAL ALLOYING

Applied Physics Letters

Amorphous Ge1-xSx(x=0.61, 0.67, and 0.72) semiconductor alloys have been found formed by ball milling of powder mixtures of elemental Ge and S. The amorphization process and the ball-milled products have been investigated by x-ray diffraction, transmission electron microscopy, and Raman scattering. The results show that amorphous Ge-S alloys may form in a self-heating reaction, driven by the large heat of formation of amorphous and/or liquid Ge-S alloys. The structure of mechanically alloyed amorphous Ge-S alloys is similar to but not exactly identical with that of rapidly cooled amorphous Ge-S alloys. The amorphization transition mechanism reported is believed to be suitable for preparing other amorphous semiconductor alloys with similar thermodynamic conditions.

关键词: magnetic-properties;ni-zr;amorphization;powders;transition;interdiffusion;germanium;systems;glasses;metals

VIM法中采用CaO坩埚对Ni基高温合金脱S的影响

牛建平 , 杨克努 , 管恒荣 , 胡壮麒

机械工程材料 doi:10.3969/j.issn.1000-3738.2002.02.002

研究了使用CaO坩埚在VIM法精炼Ni基高温合金过程中S的变化规律及加Al对脱S的影响.试验表明:当CaO坩埚中的含S量高于液态金属中的含S量时,坩埚中的S将进入金属液中而使液态金属增S.加入0.5%的Al经30min精炼后可以使液态金属中的S含量从30mg/kg降低至小于5mg/kg.对CaO坩埚内壁的XRD及成分分析表明,加Al脱S是由于在CaO坩埚壁和金属液间形成低熔点的具有很强脱S能力的3CaO@Al2O3渣.

关键词: VIM , CaO坩埚 , Ni基高温合金 , 脱S

Thermodynamic Behaviour of Fe-S-RE,Fe-Csat.-S-RE,Ni-S-RE,Cu-S-RE Solutions

Ting DU Longmei WANG Yeming WU Yuqing ZHANG Aisheng LIU Central Iron and Steel Research Institute , Beijing , 100081 , China

材料科学技术（英）

The temperature dependences of the equilibrium constants for the reactions RES_((S))=[RE]+[S]. (RE=Ce,La,Nd,Sm,Y),of the standard Gibbs energies for the RES formed and of the interaction coefficients between RE elements and S for the Fe-base,Ni-base and Cu-base solutions are sum- marized.

关键词: thermodynamics , null , null , null , null

Corrosion behaviour of carbon steel in different concentrations of HCl solutions containing H(2)S at 90 degrees C

Corrosion Science

The corrosion behavior of SAE-1020 carbon steel in H(2)S-containing solutions with different concentration of HCl at 90 degrees C was investigated by weight loss, electrochemical measurements, SEM and XRD analysis. The results showed that the corrosion rate of carbon steel increased with increasing HCl concentration. Uniform corrosion was found on the carbon steel surface in H(2)S + HCl solutions, while corrosion cavities were observed in the solution only containing H(2)S. The ratio of Faradaic process of total corrosion process increased with the increase of HCl concentration. The corrosion products were solely composed of mackinawite in the H(2)S-containing solutions with or without HCl. (c) 2011 Elsevier Ltd. All rights reserved.

关键词: Steel;Weight loss;EIS;SEM;XRD;Acid corrosion;acidic chloride solutions;hydrogen-sulfide;aqueous-solution;iron;sulfides;electrochemical-behavior;media;dissolution;impedance;polarization;environments

Quantum transport of Au-S-S-Au nanoscale junctions

Applied Physics Letters

Transport in S(2) molecules sandwiched between Au electrodes is investigated with a combination of density functional theory and the non-equilibrium Green's function method. We consider four different configurations and find that their conductances are related to the details of the bonding geometry. When S(2) connects to pyramidal-shaped electrodes at the top site, the transmission is governed by a resonance and is strongly affected by the bias. In contrast, the transport of the remaining three configurations is through several closely spaced broad molecular orbitals, and the transmission coefficient is almost flat around the Fermi level. (C) 2012 American Institute of Physics. [doi:10.1063/1.3665614]

关键词: conductance;molecule

恒位移加载条件下X65管线钢H2S应力腐蚀研究

孙新阁 , 霍立兴 , 张玉凤

腐蚀科学与防护技术

采用楔形张开加载恒位移实验研究了X65管线钢在H2S溶液中的应力腐蚀开裂行为，并得出了X65管线钢母材、焊缝和热影响区的临界应力强度因子KISCC分别为55.7093 MPa•m 1/2、33.3189 MPa•m1/2和38.0711 MPa•m1/2；平台处的裂纹扩展速率da/dt分别为3.38×10－9m/s、3.5×10－9 m/s和3.5×10－9m/s.研究结果还表明，焊缝比母材具有更高的应力腐蚀敏感性. 

关键词: 管线钢 , null , null

恒位移加载条件下X65管线钢H2S应力腐蚀研究

孙新阁 , 霍立兴 , 张玉凤

腐蚀科学与防护技术 doi:10.3969/j.issn.1002-6495.2006.03.004

采用楔形张开加载恒位移实验研究了X65管线钢在H2S溶液中的应力腐蚀开裂行为,并得出了X65管线钢母材、焊缝和热影响区的临界应力强度因子KISCC分别为55.7093 MPa·m1/2、33.3189 MPa·m1/2和38.0711 MPa·m1/2;平台处的裂纹扩展速率da/dt分别为3.38×10-9m/s、3.5×10-9m/s和3.5×10-9m/s.研究结果还表明,焊缝比母材具有更高的应力腐蚀敏感性.

关键词: 管线钢 , 临界应力强度因子 , 裂纹扩展速率