W.L. Zhang
,
R.J. Tang
,
W.X. Zhang
,
B. Peng
,
H.C. Jiang
,
H.W. Zhang
金属学报(英文版)
The magnetization reversal process of nano-size rectangle-shaped NiFe film elements with different aspect ratios have been investigated under the orthogonally applied magnetic fields by micromagnetic simulation. Different magnetization reversal modes can appear depending on whether the bias field is applied or not. When there is no bias field, double "C" state is the initial reversal state. However, when there is a bias field, "S" state is the starting mode. The larger the aspect ratio is, the larger the switching field is. But, when the aspect ratio is larger than 3, the increase of the switching field ceases. These results can provide useful information to the application of the patterned NiFe film with rectangular elements.
关键词:
NiFe film element
,
null
,
null
Gaowu QIN
金属学报(英文版)
doi:10.1016/S1006-7191(08)60117-9
Co-X(X=Cr, Mo, W) magnetic thin films were prepared by using DC magnetron sputtering, and their structures were examined by using X-ray diffraction (XRD). The amorphous forming ability (AFA) of the three alloy systems was discussed based on thermodynamic calculation and experiments. The results show that the Co-Mo thin films exhibit the largest AFA among them, and the Co-W thin films are condition-dependent amorphous while the Co-Cr thin films are hard to be amorphous, which is consistent with the thermodynamic calculation. The difference in AFA for the alloys of these three systems is finally ascribed to three main factors: differences in electronegativity, electron density and atomic size between Co and X elements.
关键词:
Amorphous forming ability
,
Co-Cr
,
Co-Mo
,
Co-W
袁江
,
宋新华
,
孙甲尧
,
龚航
航空材料学报
doi:10.11868/j.issn.1005-5053.2016.1.001
基于密度泛函理论的第一性原理，通过计算 RuAl 合金氧化物 Al2 O3和 RuO2的氧化能，考察过渡金属元素 X （X ＝W，Mo，、Cr）加入到 RuAl 合金后的占位及对氧化物 Al2 O3和 RuO2的结构稳定性影响。研究表明：经过渡金属元素 X 合金化后，Al2 O3和 RuO2的氧化能均有所增大，增大 Al2 O3氧化能的顺序为：W ＞Mo ＞Cr；增大 RuO2氧化能的顺序为：Mo ＞Cr ＞W，且 RuO2氧化能增大幅度大于 Al2 O3。通过态密度、电荷密度等因素的分析，阐明了 W 对提高 RuAl 抗氧化性能的根本原因是降低了 Al-O 和 Ru-O 的共价键特性，增加了 Al-O 和 Ru-O 的离子键特性；金属元素 X（X ＝W，Mo，Cr）可阻碍 RuAl 金属化合物发生内氧化过程，有利于在 RuAl 表面层的横向方向上形成连续性致密的 Al2 O3氧化层。
关键词:
RuAl
,
第一原理
,
抗氧化性能
,
稳定性
,
氧化能
彭可
,
易茂中
,
冉丽萍
,
葛毅成
稀有金属材料与工程
根据固体与分子经验电子理论(EET),利用平均原子模型对(Mo_(1-x),W_x)Si_2)固溶体进行价电子结构分析,并分别与MoSi_2和WSi_2基体进行比较.结果表明,随着x值的增加,(Mo_(1-x),W_x)Si_2固溶体的主干键络键能、最强键上共价电子数和共价电子总数百分比均逐渐增加,表明固溶体的熔点、硬度和强度均逐渐增加.
关键词:
(Mo_(1-x)
,
W_x)Si_2固溶体
,
价电子结构
,
EET理论
,
性能
颜晓华
,
彭宇
,
苏明
硬质合金
doi:10.3969/j.issn.1003-7292.2015.04.008
复式碳化物是一种硬质合金行业和其他新材料行业广泛使用的原料,常用的复式碳化物由TiC、WC、TaC等固溶生成.本方法以m(Li2B4O7)∶m(LiBO2)=67∶33为熔剂制备复式碳化物的熔融玻璃片,采用Bruker公司的S8 Tiger型顺序式X射线荧光光谱仪和Spectra plus基体效应校正等软件,在熔融条件、标样的设置、转换系数的计算、仪器条件等方面进行探讨,建立了X射线荧光光谱仪测定复式碳化物中W、Ti、Ta、Fe的含量方法,方法分析测定范围(氧化物)W 25.55％～52.41％、Ti 8.89％～31.48％、Ta 15.03％～28.54％、Fe 0.032％～ 1.07％,结果表明,方法的精密度和准确度较好.
关键词:
复式碳化物固溶体
,
化学分析
,
X射线荧光光谱
,
W
,
Ti
,
Ta
,
Fe
Powder Diffraction
Ternary Al-Cu-W alloys were investigated. The previously reported Al(3)Ti-type phase (space group 14/mmm) with the average composition Al(67)Cu(11.5)W(21.5) was found to have a=3.7296(4) angstrom and c=8.3797(10) angstrom. The ternary phase forming around Al(67)Cu(21)W(12) has a hexagonal structure with a=8.6594(13) angstrom and c=15.2677(21) angstrom. (C) 2011 International Centre for Diffraction Data. [DOI: 10.1154/1.3549770]
关键词:
Al-Cu-W;powder X-ray diffraction;system
Journal of Materials Research
The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.
关键词:
room-temperature
