Aiping XIAN Zhongyao SI Institute of Metal Research
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Academia Sinica
,
Shenyang
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110015
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China
材料科学技术（英文）
The bond strength of the Sn based ternary active solders,Sn-5Ti with various contents of Ag,Cu,In, Ni or AI on sialon ceramic was investigated by the ceramic/ceramic joint joining.The bond strength of Sn-STi (about 80 MPa) may increase to 90-100 MPa by small addition of Ag or Cu (about 5-10%).A little Ni (about 1-3%) in the solder is slightly beneficial,but too more Ni (more than 5%) is harmful.Small addition of In is trivial,but too more In is detrimental.On the other hand,small addi- tion of AI in the active solder decreases greatly the bond strength of the solder,therefore it is very harmful.In discussion,three suggestions for selection of the third element to increase the bond strength of the soft solders on ceramic,i.e.with a high surface energy,benefiting to wetting on ce- ramic and strengthening the soft solder itself,have been made.
关键词:
bond strength
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null
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MA Zongyi YAO Zhongkai Harbin Institute of Technology
,
Harbin
,
China
金属学报(英文版)
The SiC_w/Al composite prepared by squeeze casting has a combination of superior room temperature specific strength and modulus together with excellent thermal properties.The extrusion can make an improvement on the strength and ductility of the composite from 582 MPa as squeeze casted up to 639 MPa,and on the transformation from isotropic to the anisotropic structure.This seems to be explained by the orientation of whiskers and the densification of dislocations in matrix.TEM observation indicates that the stacking fault is the usual planar defect on the SiC_w surface. composite;;SiC whisker;;Al alloy;;microstructure
关键词:
composite
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null
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null
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S.H.O
材料科学技术（英文）
The magnetic property of soft magnetic metals and alloys depends strongly on the crystallographic orientation. In automated equipment for orientation research. the intensity for drawing up the pole figure is measured in detail. The present research shows that the accurate pole figure can be drawn up without measuring concretely the intensity. For directional Si steel sheet the measuring step may be 4 similar to 5 degrees. In this paper the experimental equation for defocusing correction was derived from the experimental data in different specimens with random orientation.
关键词:
Corrosion
This paper introduces the design of a localized corrosion rate monitoring instrument that can monitor and evaluate the maximum and stable localized corrosion rate of a nonpassivable metal in a corrosive environment by measuring the current density in a corrosion sensor with an occluded anode.
关键词:
instrument;localized corrosion rate;monitor
Guoyou GAN
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Xiuhua CHEN
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Jingchao CHEN
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Xiaolong ZHOU
材料科学技术（英文）
Interaction between single crystal Si and TiC block was studied by electron probe micro analysis (EPMA). The distribution of the reaction products from Si to TiC is reported. The diffusion kinetics constant of Si is given. The implications of the observed microstructure are discussed.
关键词:
Daqian SUN
,
Zhenfeng ZHOU
,
Wenquan WANG
,
Lian LIU
材料科学技术（英文）
The effects of Si, Mn and Al on the microstructure and mechanical properties of ADI weld have been studied. The microstructure of ADI weld metal mainly consists of bainitic ferrite and retained austenite. Mechanical properties of ADI weld increase with increasing Si content, but an excess of Si(3.79%) results in decreasing the austemperability owing to decreasing the carbon content of the matrix austenite. Mn increases the retained austenite volume fraction, but the ductility and impact toughness of weld obviously decrease with increasing Mn content because of increased amount of martenite and twin martenite. In the range of 0.13%~0.64%, increasing Al content favours improving the mechanical properties of ADI weld. Therefore, it is very important to select suitable Si, Mn and Al contents to improve mechanical properties of ADI weld.
关键词:
ADI weld metal
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null
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null
Shihong XU Pengshou XU Mingrong JI Xianming LIU Maosheng MA Jingsheng ZHU Yuheng ZHANG Structure Research Laboratory
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University of Science and Technology of China
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Hefei
,
230026
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ChinaZhenjia XU Institute of Semiconductor
,
Academia Sinica
,
Beijing
,
100083
,
China
材料科学技术（英文）
The alkali-metal Na adsorption on Si(100)2×1 surface and its promoted oxidation and Si oxide growth have been investigated by means of thermal desorption,work function,Auger electron spectroscopy and photoemission electron spectroscopy.The experimental data showed that there was a new state,interface electron state,near the Fermi level after the deposition of Na atoms.It was found that the presence of Na always caused an increase of the oxygen initial uptake whereas the promotion of Si oxide growth was observed only at the coverage of Na greater than 0.5 ML.A new mechanism of Na-promoted Si oxide growth is suggested in this paper.
关键词:
adsorption
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null
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null
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