H.Z. Yang
,
X.G. Sun
,
W.Q.Huang
,
M.L. Li
,
X.M. Yu
,
B.S.Zhang
,
Y.Qi
,
Q. Zhao
金属学报(英文版)
An electrochemical technique has been introduced and applied to fabricate superconducting MgB2 films in molten salts. MgCl2, Mg(BO2)2, NaCl, and KCl were used as electrolyte, graphite was used as the anode, and copper was used as the cathode, respectively. X-ray diffraction (XRD) analysis was chosen to investigate the phase composition and crystallinity of the films at different electrolysis temperatures. Standard four-probe technique and SQUID were applied to investigate the temperature dependence of resistance (R-T) properties and magnetic properties of the films, respectively. The results indicate that MgB2 films have been fabricated on the copper cathodes, and superconducting transition takes place close to 50 K.
关键词:
MgB2 film
,
null
,
null
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
LUO Meiqing CHEN Nianyi Shanghai Institute of Metallurgy
,
Academia Sinica
,
Shanghai
,
ChinaYU Zhizhong Shanghai Institute of Testing Technics
,
Shanghai
,
ChianNING Yuantao ZHOU Xinming Kunming Institute of Precious Metals
,
Kunming
,
China CHEN Nianyi
,
Professor
,
Shanghai Institute of Metallurgy
,
Academia Sinica
,
Shanghai 200050
,
China
金属学报(英文版)
The electronic structure of Pd-Y-Si glass has been investigated by ESCA and quantum chem- ical calculation.It was found that the valence electrons of Y transferred to Si atoms in this metallic glass,forming polar covalent bonds.Perhaps these strong covalent bonds link Si and Y atoms to form clusters that hinder the process of crystallization.
关键词:
Pd-Y-Si glass
,
null
,
null
,
null
LI Laifeng XING Zhongshu Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
China XING Zhongshu
,
professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
The solubilities of Ce,Nd and Y in α-Fe at 873 to 1153 K have been deter mined by means of electron microprobe quantitative analyses.The temperature dependences of the solubilities were obtained from the experimental data.The results have been compared with those deter- mined by three other technigues,very good agreement was obtained between the results of all these techniques.
关键词:
α-Fe
,
null
,
null
,
null
,
null
翟庆洲
,
蔡建岩
,
于淼
稀有金属材料与工程
以沸石Y及以甲基三甲氧基硅烷对沸石Y进行表面改性后的Y(m)沸石作主体,用离子交换法制备Cd-Y及Cd-Y(m)样品,然后以硫代乙酰胺取代有毒的硫化氢作硫源,水热法制备Y-CdS及Y(m)-CdS主-客体纳米复合材料.利用粉末XRD、化学分析、红外光谱、固体扩散漫反射吸收光谱、发光研究对制备的样品进行了表征.化学分析表明,CdS已进入沸石Y(Ym)主体中;XRD结果表明,CdS进入沸石Y(Ym)后,制得的复合材料沸石骨架仍然存在,且保持高度有序性,不改变骨架的长程有序性;红外光谱结果表明,在所制备的Y-CdS及Y(m)-CdS样品中,有Si-O-Cd新键生成;固体扩散漫反射吸收光谱结果表明,沸石Y和Y(m)对可见光基本无吸收,Y-CdS和Y(m)-CdS吸收无明显差别;组装CdS后,Y-CdS及Y(m)-CdS产生发光现象.所制得的Y-CdS及Y(m)-CdS主-客体纳米复合材料具有作为发光材料的潜在性.
关键词:
Y沸石
,
Y改性沸石
,
甲基三甲氧基硅烷
,
纳米CdS
,
主-客体纳米复合材料
,
表征
D.Q. Wan
,
G.C. Yang
金属学报(英文版)
The microstructure formation and mechanical property involving icosahedral quasicrystal (I-phase) in the Y-rich Mg-Zn-Y alloy have been studied. The equilibrium formation of I-phase from the Y-rich Mg-Zn-Y melt is through a peritectic reaction between the Y-rich melt and the primary W-phase, which is discussed in detail. The independent nucleation and coupling growth mechanism between the W-phase and the I-phase, from the melt, are revealed, which is significant for understanding the peritectic reaction process involving icosahedral quasicrystal in the Mg-Zn-Y alloy. The mechanism of the quasicrystal phase strengthened magnesium alloys is also discussed here.
关键词:
Mg-Zn-Y
,
null
,
null
LI Bei WU Shuangxia MENG Guang'en JIANG Liping PANG Wenjie Baotou Research Institute of Rare Earth
,
Baotou
,
China Baotou Research Institute of Rare Earth
,
P.O.Box 131
,
Baotou 014010
,
China
金属学报(英文版)
With the increase of Y content in the Fe-20Cr-4AI-Y alloy,the uniform deformability of tensile specimens was found to be slightly decreased,as well as,the fracture strength and re- duction after necking remarkably dropped.This seems to be dependent upon the brittle phase containing Y.The behaviour of Y-containing phase may be improved by adjusting the metallurgical technological process.
关键词:
Fe-Cr-A1 alloy
,
null
,
null
腐蚀学报（英文）
研究了Y、Zr、Si对FeAl金属间化合物在1000～1200℃下循环氧化性能的影响,并用X射线衍射、扫描电镜及能谱分析等手段分析了氧化产物。结果表明,Y、Zr、Si的加入大大提高了FeAl金属间化合物表面氧化膜的抗剥落能力。从氧化动力学上看,Y和Zr或Y和Si的同时加入比单独加Zr效果好。
关键词:
FeAl金属间化合物
,
null
,
null
张康侯
,
陈亮维
,
尹俊美
,
陈藜莉
,
谢明
,
符世继
贵金属
doi:10.3969/j.issn.1004-0676.2008.04.001
在Au-Ag、Au-Y和Ag-Y二元合金相图的基础上,采用X-射线衍射分析、电子探针等手段研究了Au-Ag-Y三元系中富金-银区域(Y≤34at%)的700℃等温截面.发现:在该截面的富金银侧沿着Au-Ag二元匀晶系存在一个单相区Au(Ag)或Ag(Au);在二元金属间化合物Au2Y和Ag2Y之间存在一个无限固溶体区域(Au2Y)或(Ag2Y).在该部分700℃等温截面上一共有6个单相区:Au(Ag) 或 Ag(Au)、Au6Y、Au51Y14、α(Au2Y) 或 (Ag2Y)、 Au3Y和 Ag51Y14;9个两相区:Au(Ag)+ Au6Y、 Au(Ag)+ Au51Y14、 Au(Ag)+ Au3Y、 Au(Ag)+ α(Au2Y)、 Au(Ag)+ Ag51Y14、Ag51Y14+α(Au2Y)、α(Au2Y)+ Au3Y、 Au3Y+ Au51Y14 和 Au51Y14+ Au6Y;4个三相区: Ag51Y14+α(Au2Y)+Au(Ag)、α(Au2Y)+ Au3Y+ Au(Ag)、 Au3Y+ Au51Y14+ Au(Ag) 和 Au51Y14+ Au6Y+ Au(Ag).在Au-Ag-Y三元系的该成分区域没有发现新的三元中间相.
关键词:
材料科学基础学科
,
Au-Ag-Y三元系
,
合金
,
相图
,
等温截面
