贺友多
,
Y.SAHAI
金属学报
研究出一个表示连铸机中间包内的湍流流动和混合的数学模型,该模型包括求解三维湍流Navier-Stokes方程和K-ε两方程的湍流模型.对矩形断面中间包的流动参数和停留时间作出了预报,然后又用这一模型预报一般工业用的中间包流场,这种中间包的侧墙是稍有倾斜,而不是垂直的.结果表明,流场起了变化,这一点也可能对工业上的应用产生重大影响.把理论上的预报结果与水模型中的测量值作了比较.对中间包内的流场的认识也是设计最优化的依据.
关键词:
连铸机中间包
,
three-dimensional turbulent fluid field
,
mixing
,
residence time distribution
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
腐蚀科学与防护技术
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
