K. Mii (Sumitomo Metal Industries
,
Ltd.
,
1-t-3 Otemachi
,
Tokyo 100
,
Japan)M Amano (National Research Institute for Metals
,
1-2-1 Sengen
,
Tsukuba 305
,
Japan)
金属学报(英文版)
The R & D of hydrogen absorbing alloys in Japan started in the early 1970s.Many alloys such as TiMm1.5 based alloys, Fe-Ti-O alloys (e.g. FeTi1.15 O0.024) andthe(mischmetal)Ni5 based alloys (e.g. MmNi4.5 Cr0.46 Mn0.04) were developed by the early 1980s. The application of these alloys to hydrogen storage, heat storage, heat pump, hydrogen purification and motor vehicles has been tried in many iaboratories,and the various techniques for using hydrogen absorbing alloys have been developed.The standarkization of evaluation methods for hydrogen absorbing alloys has been promoted by the Ministry of International Trade and Industry (MITI), and four of them were established as Japanese Industrial Standard (JIS).Alloys for Ni-Metal Hydride batteries have been extensively investigated since 1987in Japun. Mm-Ni-Co-Al-Mn alloys (e.g. MmNi3.55 Co0.75Al0.9Mn0.4) have been devel-oped and commereialized since 1990. The amount of production of small-size Ni-MH batteries in 1995 was about three hundred milliion in number and about one hundred billion yen. The R & D for higher enerpy-density Ni-MH batteries is intensively in progress.MITI and STA (Science and Technology Agency) have promoted the R & D of hydro-gen absorbing alloys in Japan by carrying out the national projects such as Sunshine Program (MITI: 1974-1993) and Utilization of Wind Engeray (STA 1980-1985). The New Sunshine Program (MITI 1993-2020) have started in 1993. This program con-tains the application of hydrogen absorbing alloys to Economical- Enerpy- City System and to We-NET (International Clean Energy System of Technology Utilizing Hydro-gen: World Energy Network.
关键词:
hydrogen absorbing alloy
,
null
,
null
,
null
Surface Science
In situ electrochemical scanning tunneling microscopy (STM) has been used to examine the structures of benzenethiol adlayers on Au(100) and Pt(100) electrodes in 0.1 M HClO4, revealing the formation of well-ordered adlattices of Au(100)-(root 2x root 5) between 0.2 and 0.9 V and Pt(100)-(root 2 x root 2)R45 degrees between 0 and 0.5 V (versus reversible hydrogen electrode), respectively. The coverage of Au(100)-(root 2 x root 5) is 0.33, which is identical to those observed for upright alkanethiol admolecules on Au(111). In comparison, the coverage of Pt(100)-(root 2 x root 2)R45 degrees - benzenethiol is 0.5, much higher than those of thiol molecules on gold surfaces. This result suggests that berizenethiol admolecules on Pt(100) could stand even more upright than those on Au(100). All benzenethiol admolecules were imaged by the STM as protrusions with equal corrugation heights, suggesting identical molecular registries on Au(100) and Pt(100) electrodes, respectively. Modulation of the potential of a benzenethiol-coated Au(100) electrode resulted in irreversible desorption of admolecules at E <= 0.1 V (vs. reversible hydrogen electrode) and oxidation of admolecules at E >= 0.9 V. In contrast, benzenethiol admolecule was not desorbed from Pt(100) at potentials its negative as the onset of hydrogen evolution. Raising the potential tendered deposition of more benzenethiol molecules before oxidation of admolecules commenced at E > 0.9 V. (c) 2006 Elsevier B.V. All rights reserved.
关键词:
scanning tunneling microscope;adsorption;benzenethiol;Au(100);Pt(100);solid-liquid interface;self-assembled monolayers;au(111);adsorption;surfaces;butanethiol;pt(111);gold;reconstruction;methanethiol;transitions
Liuding WANG
,
Laizhu JIANG
,
Ming ZHU
,
Xiao LIU
,
Wangmin ZHOU
材料科学技术（英文）
The influence of double aging on the microstructure and mechanical properties of ultrahigh strength steel Aermet 100 was analyzed. Under the double aging, there is no apparent decrease in the strength of steel. However, the impact fatigue life can be prolonged by 35.5% and dynamic fracture toughness be raised by 22.6% respectively, as compared with the normal aging. Based on the observation of microscopic structure, the physical mechanism of the prolongation of impact fatigue life and the enhancement of stability of the reverted austenite, AR, is analyzed further. The results show that this new technique is a breakthrough of combination optimization between strength and toughness for Aermet 100 steel. In the light of the current understanding on this subject, the volume fracture of soften and tough AR formed in process of heat preservation at higher temperature of double aging increases drastically. Moreover, during the treatment of lower temperature of double aging, the carbon separating from the martensitic ferrite will diffuse into AR, resulting that the martensitic brittleness decreases and the stability of AR increases.
关键词:
Ultrahigh strength steel
,
null
,
null
,
null
潘勇
,
管伟明
,
陈松
,
张昆华
稀有金属材料与工程
采用密度泛函理论的平面波赝势法,分别研究在ZrO2(100)面上以氧为键桥和以锆为键桥的Pt(100)/ZrO2(100)界面模型的结合能、电子结构以及等电荷差分密度分布图.结果发现:在以氧为键桥的Pt(100)/ZrO2(100)-bridge o界面结合能为1.978 J/m2,而以锆为键桥的Pt(100)/ZrO2(100)-bridge Zr界面结合能为10.035 J/m2,前者的界面结合能低于后者的界面结合能,即以锆为键桥的ZrO2(100)更容易与Pt(100)面结合.通过电子结构和等电荷差分密度分布图分析可知,以氧为键桥的Pt(100)/ZrO2(100)-bridge o时,主要是锆氧之间存在电子转移,而以锆为键桥的Pt(100)/ZrO2(100)-bridge Zr时,不仅锆氧之间、而且铂锆之间也存在电子转移,铂锆之间主要是锆的4d电子轨道和铂的5d以及部分6s、5p电子轨道上的电子发生了转移并且成键结合,这说明在铂基材料中以锆为键桥的界面结合能有效提高铂基材料的强度.
关键词:
密度泛函理论
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Pt(100)/ZrO2(100)
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结合能
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电子结构
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等电荷差分密度图
黎建明
,
屠海令
,
郑安生
,
邓志杰
,
罗志强
稀有金属
doi:10.3969/j.issn.0258-7076.2001.05.001
采用 LEC 方法研制出掺锌(100) GaSb 单晶;用霍尔测量法算出的锌掺杂浓度计算得出锌的有效分凝系数 keff 约为 0.84±0.01,沿晶体生长方向随着锌浓度的提高,位错密度缓慢增加,数值约为 (2～3.2)×103cm-2,当掺锌浓度大于 3×1019cm-3 以后, GaSb 发生简并,载流子浓度随掺锌浓度的增加缓慢提高.采用重掺锌母合金作掺杂剂,可减少锌的损失,较好地控制掺杂浓度.
关键词:
GaSb
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有效分凝系数
,
位错密度
,
简并
Physical Review B
Through systematic density functional calculations using the full potential linearized augmented plane-wave (FLAPW) method, the rhombohedral magnetostriction (lambda(111)) of Fe100-xAlx and Fe100-xGax alloys are studied for x up to 25. Theoretical calculations satisfactorily reproduce the main features of experimental lambda(111)(x) curves, except for dilute alloys with x < 5. Detailed analyses on electronic and structural properties indicate the importance of availability and symmetry of dangling bonds for the sign change of lambda(111) around x = 16. In addition, the impurity induced local distortion might be a possible reason for the disagreement between theory and experiment for lambda(111) of the bulk bcc Fe. DOI: 10.1103/PhysRevB.86.224410
关键词:
fe-ga alloys;al alloys;magnetoelasticity;surfaces;anisotropy;galfenol;model
D.Y.Li(Dept. of Mater. Sci & Eng.
,
The Pennsylvania State University
,
University Park
,
PA 16802
,
USA )B.Debray and J.A.Szpunar(Dept. of Metall. Eng.
,
McGill University
,
3450 Uuiversity Street
,
Molitreal
,
PQ
,
Canada H3A 2A7)
材料科学技术（英文）
The (100) texture of solidified fcc metals, caused by the preferential (100) dendrite growth, could be closeIy related to solid/melt interfaces which behave differently along different crystallographic orientation. The stability and roughness of {111} and {100} solid/melt interfaces of fcc metals were investigated using a modified Temkin multi-layer model. It is demonstrated that {100}crystal/melt interface is more unstable and rougher than {111} interface. The effect of the stability of crystal/melt interface on the (100) texture formation in solidified fcc metals has been analysed and discussed.
关键词:
贾书君
,
刘清友
,
段琳娜
材料热处理学报
探讨了X100热轧钢带的成分选择、组织设计和强韧化控制等内容.结果表明:为了满足X100热轧钢带较高的强度要求,碳当量最好能控制在0.55以上;细化的“粒状贝氏体+板条贝氏体”混合组织是X100热轧钢带的组织控制目标;X100热轧钢带强度的实现是细晶强化、固溶强化、位错强化、相变强化等多种强化方式于一体的强化方式共同作用的结果;显微组织的细化尤其是相变前奥氏体的细化和M/A岛尺寸、数量的优化控制,是X100管线钢获得优异韧性的关键.
关键词:
碳当量
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粒状贝氏体
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板条贝氏体
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晶粒细化
,
M/A岛
,
强韧化控制
周峰
,
吴开明
,
康永林
,
陈建新
材料热处理学报
利用Gleeble-1500热模拟实验机研究了X100管线钢动态再结晶和静态再结晶行为.通过单道次压缩实验研究了X100管线钢的动态再结晶规律,确定了动态再结晶的临界变形条件,得到了奥氏体的动态再结晶图.通过双道次压缩实验研究了X100管线钢的静态再结晶规律,得到了X100管线钢的静态再结晶动力学方程.通过线性回归得出X100管线钢的再结晶激活能为365 k J/mol,由化学成分算得的再结晶激活能为320 k J/mol,两者比较接近,相互印证.
关键词:
X100管线钢
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动态再结晶
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静态再结晶
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激活能
