X.H.Mao
,
Y.Zhou
,
M.S.Wu
,
B.C.Cai
金属学报(英文版)
Sensitive magnetic field sensor with good performances can be fabricated utilizing the giant magneto-impedance (GMI) effect of soft magnetic multi-layer thin films. The transverse and longitudinal GMI effect in patterned FeSiB/Cu/FeSiB tri-layer films with the change of external magnetic field and frequency were studied at the same time. The change of the impedance of the films with the external magnetic fieldand frequency was shown. Comparing the longitudinal and transverse effect, the transverseeffect has a larger linear range from zero magnetic field to a quite large magnetic field at all frequencies, and the change still were not saturated until the external magnetic field reached 1.2×10^4A/m, which illustrated that the films can be utilized to detect laraer maanetic fields than now presented GMI sensors.
关键词:
giant magneto-impedance effect
,
null
,
null
Applied Surface Science
A novel kind of micro-arc oxidation (MAO) coating was prepared on magnesium alloy surface coated with rare earth conversion film (RE-film) in an alkaline aluminum oxidation electrolyte by AC power source. Inspection of scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) microspectroscopy, the structure and composition of MAO coating formed on AZ91D with RE-film under different applied voltages were investigated and the performance of the optimized MAO coating compared with the MAO coating directly formed on magnesium alloy. As the pretreatment of magnesium alloy with RE-film, the cerium oxides can be incorporated into the MAO coatings, reduce porosity of the MAO coating surface and enhance the thickness of MAO coating. These structure features and the cerium oxides incorporated into the MAO coating result in greatly improved corrosion resistance. Base on electrochemistry impedance spectroscopy (EIS) measurement, the electronic structure and composition analysis of the MAO coating, a double-layer structure, with a compact inner layer and a porous outer layer, of the coating was proposed for understanding its corrosion process. (C) 2010 Elsevier B.V. All rights reserved.
关键词:
Magnesium alloy;Rare earth conversion film;Micro-arc oxidation;Porosity;az31 magnesium alloys;micro-arc oxidation;mg-al alloys;electrolyte;resistance;cerium;phosphate
杨巍
,
汪爱英
,
柯培玲
,
代伟
,
张学谦
材料工程
doi:10.3969/j.issn.1001-4381.2012.04.019
采用线性离子束沉积技术于AZ80镁合金微弧氧化(MAO)陶瓷层表面沉积不同厚度的类金刚石碳(DLC)膜,形成DLC/MAO复合膜层.对比研究4种膜基系统的表面结构特征、力学性能以及摩擦学性能差异.结果表明:随DLC膜厚度增加,复合膜层表面微孔数量减少,孔径减小,但凹凸不平趋势增加,且DLC膜表面颗粒特征更加明显,表现为DLC-80min/MAO/AZ80膜基系统具有最小的表面粗糙度,最大的硬度H、弹性模量E及H/E值；不同厚度DLC/MAO/AZ80膜基系统平均摩擦因数较MAO/AZ80显著降低；DLC膜厚度增加导致3种复合膜基系统的表面微观结构改变,使得摩擦因数与磨痕形貌存在差异；各膜基系统表面磨痕处均形成了Fe的转移层,由于表层DLC膜“裸露”的大量C对磨损界面具有很好的润滑作用,而使得镁合金基体获得有效保护.
关键词:
镁合金
,
微弧氧化
,
类金刚石碳膜
,
微观结构
,
性能
Materials and Corrosion-Werkstoffe Und Korrosion
Micro-arc oxidation (MAO) has been accomplished on Mg-Li alloy in alkaline polyphosphate electrolytes without and with the addition of 10?g/L?K2TiF6. The surface/cross-section microstructures of the fabricated coatings were analyzed by scanning electron microscope (SEM); the compositions of the fabricated MAO coatings were analyzed by X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDAX); the corrosion behaviors of bare and MAO coated Mg-Li alloys were evaluated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) in 3.5?wt% NaCl solution. Novel hybrid MAO coatings which showed hybrid composition of MgF2/Ti2O5/Ti6O11/MgO, as well as hybrid structure of a dense inner layer, a dense outer layer and an intermediate layer with some sealed/semi-sealed pores, had been fabricated on Mg-Li alloy in alkaline polyphosphate electrolytes with the addition of K2TiF6. Meanwhile, the corrosion resistance of the fabricated MAO coatings was improved obviously as the result of the addition of K2TiF6 in the electrolytes. Moreover, the multiple roles of ${\rm TiF}_{{\rm 6}}boolean AND{{\rm 2}{-} } $ on the MAO process accounted for the fabrication of the corrosion-resistant hybrid MAO coatings.
关键词:
corrosion resistance;Mg-Li alloy;micro-arc oxidation;az91d magnesium alloy;corrosion-resistance;phosphate electrolytes;ceramic coatings;zn alloy;silicate;performance;aluminum;behavior
彭启才
,
周心明
,
蔡伯埙
材料研究学报
采用等离子体辉光放电单室系统制备的a-Si:H/a-Si_(1-x)C_x:H 多层膜结构具有低的暗电导和高的光电导特性,且不同于单层膜,有明显的S-W 效应。随着子层厚度L 减小,多层膜曝光态(B)的暗电导率σdB 较退火态(A)的σdA 减小快,即光诱导衰退程度增大,而光电导无明显变化。本文还测定了此多层膜结构的光能隙E_g,得到随子层厚度减小“蓝移”的结果。用一维单量子阱模型作了讨论,实验值与理论计算符合较好。
关键词:
a-Si:H/a-Si_(1-x)C_x:H
,
superlattice
,
amorphous semiconductors electrical properties
,
optical properties
,
null
潘亮
,
程知松
,
范爱琴
,
蔡庆伍
,
郭新文
钢铁
对采用XH轧制法轧制H型钢的轧制力进行分析，以西姆斯公式为基础，采用多元线性回归的方法建立万能轧机轧制H型钢的轧制力数学模型。用编程的方法对数学模型的系数进行求解，给出几种规格的H型钢回归模型的系数，并将计算结果与实测的数据进行对比分析，得到的结果与实测值的误差在6％以内，表明模型具有较高的应用价值。
关键词:
H型钢;数学模型;回归分析;轧制力
潘亮
,
程知松
,
范爱琴
,
蔡庆伍
,
郭新文
钢铁
对采用X-H轧制法轧制H型钢的轧制力进行分析,以西姆斯公式为基础,采用多元线性回归的方法建立万能轧机轧制H型钢的轧制力数学模型.用编程的方法对数学模型的系数进行求解,给出几种规格的H型钢回归模型的系数,并将计算结果与实测的数据进行对比分析,得到的结果与实测值的误差在6%以内,表明模型具有较高的应用价值.
关键词:
H型钢
,
数学模型
,
回归分析
,
轧制力
刘永明
,
贺晓慧
,
陈义旺
,
伍青
催化学报
采用双-(β-酮萘胺)镍(Ⅱ)为主催化剂,以甲基铝氧烷(MAO)为助催化剂,在甲苯溶剂中进行了苯乙烯聚合实验,并考察了聚合温度、Al/Ni摩尔比、单体浓度和聚合时间等因素对聚合反应的影响. 结果表明,双-(β-酮萘胺)镍(Ⅱ)/MAO催化剂显示出很高的催化活性,可催化苯乙烯聚合得到中等分子量和分子量分布较窄(Mw/Mn＜1.6)的聚苯乙烯. 采用核磁共振氢谱、核磁共振碳谱、傅里叶变换红外光谱、差示扫描量热法和广角X射线衍射技术对聚合产物进行了表征. 结果表明,所得聚合物为无规聚苯乙烯.
关键词:
镍
,
络合物
,
后过渡金属催化剂
,
苯乙烯
,
聚合
,
聚苯乙烯
M. Vergnat
,
M.Gerl+
,
Laboratoire de Métallurgie Physique et Science des Maériaux (U.R.A.au C.N.R.S.No. 155)
,
Universite de Nancy 1
,
France
材料科学技术（英文）
Amorphous Si_(1-x)Sn_x alloys have been prepared by co-evaporation onto substrates maintained at liquid nitrogen temperature. Their atomic structure is investigated using density measurements, scanning high-energy electron diffraction and Mossbauer spectroscopy. The optical and electrical properties are reported. Then, a method to hydrogenate the films during the evaporation process is described and applied to the preparation of amorphous semiconductors from pure silicon to pure tin. Finally, multilayers of type Si / Si:H / ... or Si:H / Si:D / ... are studied. The modulation of hydrogen is shown by low-angle neutron scattering and measurements of hydrogen diffusivity are presented.
关键词:
amorphous alloy
,
null
,
null
