TONG Huayu
,
DING Bingzhe
,
JIANG Honggang
,
LI Shuling
,
LI Gusong
,
WANG Jingtang State Key Laboratory of RSA
,
Institute of Metal Research.Academia Sinica.Shenyang
,
China
金属学报(英文版)
A new method was developed for preparing nanocrystalline alloy made of the identi- cal compositional Fe_(78)B_(13)Si_9 amorphous ribbon by suitable isothermal annealing.Its microstructure and some structure-sensitive properties.including thermal expansion,spe- cific heat,etc.,have been studied and measured.Comparative analysis of properties was also carried out with amorphous and coarse-grained crystalline alloys of same composi- tion,thus.it is believed that so novel differences in properties from usual materials would be made by the particular microstructure of short range disorder of the nanocrystalline alloy.
关键词:
nanocrystalline alloy
,
null
,
null
,
null
,
null
Chunju WANG
,
Debin SHAN
,
Bin GUO
,
Jian ZHOU
,
Lining SUN
材料科学技术（英文）
From the viewpoint of production engineering, microforming is considered as an effective process to fabricate various microparts. Several key problems in microforming processes were investigated. A new microforming apparatus with a high stiffness piezoelectric actuator as the punch driver was developed to produce microparts. To improve the forming abilities and locate the billets, a floating microdie was designed. The size effects of the billets and die cavities on the microforming abilities were studied with upsetting and coining tests, respectively. And the isothermal microforming process of microgears was performed with the developed microforming apparatus. Several analysis methods were used to evaluate the forming quality of the microparts.
关键词:
Microforming
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尺寸效应
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微塑性成形设备
,
浮动
Express Polymer Letters
The state-of-art and key problems of carbon nanotube (CNT) based polymer composites (CNT/polymer composites) including CNT/polymer structural composites and CNT/polymer functional composites are reviewed. Based on the results reported up to now, CNTs can be an effective reinforcement for polymer matrices, and the tensile strength and elastic modulus of CNT/polymer composites can reach as high as 3600 MPa and 80 GPa, respectively. CNT/polymer composites are also promising functional composite materials with improved electrical and thermal conductivity, etc. Due to their multi-functional properties, CNT/polymer composites are expected to be used as low weight structural materials, optical devices, thermal interface materials, electric components, electromagnetic absorption materials, etc. However, the full potential of CNT/polymer composites still remains to be realized. A few key problems, such as how to prepare structure-controllable CNTs with high purity and consistently dependable high performance, how to break up entangled or bundled CNTs and then uniformly disperse and align them within a polymer matrix, how to improve the load transfer from matrix to CNT reinforcement, etc, still exist and need to be solved in order to realize the wide applications of these advanced composites.
关键词:
polymer composites;carbon nanotubes;mechanical properties;electrical;properties;thermal properties
Corrosion Science
The early stages of the evolution of atmospheric corrosion of carbon steels exposed in both a laboratory simulated and a natural atmosphere environment in Shenyang have been observed by in situ scanning electron microscopy. In the case of laboratory cyclic wet-dry tests, even though the chloride content level is very low, filiform corrosion is initiated in the early stage. The filiform corrosion grows in random directions, forming a network of ridges. White nodules nucleate and grow on the ridges during continued corrosion and eventually connect with each other to form the initial corrosion scale. Pits were also found on the surface beneath corrosion products. In the case of a natural atmospheric environment, both filiform corrosion and other localized corrosion, such as pitting and inter-granular attack take place in the initial stage. It is obvious that there is variety of localized corrosion in the initial stage of atmospheric corrosion. (C) 2007 Elsevier Ltd. All rights reserved.
关键词:
steel;atmospheric corrosion;initial stage;localized corrosion;in-situ;iron;electrolyte;thickness
材料科学技术（英文）
The key problems of cold power spinning of Ti-15-3 alloy are studied. Reasonable biller preparation methods are presented to improve crystal structure and avoid crack of billet. Influences of original wall thickness, reduction rate and feed rate on expanding in diameter are analyzed and some methods to prevent expanding in diameter are given.
关键词:
Debin SHAN
,
Yan LU
,
Ping LI
,
Yi XU
材料科学技术（英文）
The key problems of cold power spinning of Ti-15-3 alloy are studied. Reasonable biller preparation methods are presented to improve crystal structure and avoid crack of billet. Influences of original wall thickness, reduction rate and feed rate on expanding in diameter are analyzed and some methods to prevent expanding in diameter are given.
关键词:
Author S.T. TU
,
J.M. Gong and X. Ling Nanjing University of Chemical Technology
,
Nanjing 210009
,
ChinaManuscript received 18 October 1998
金属学报(英文版)
In order to interpret the test results of crossweld specimens for application in practical welded components, the present paper studies the high temperature behavior of laboratory cross weld specimens in terms of the uniaxial material tests and numerical simulations. It is found that the crossweld specimen may be used for the high temperature strength assessment, but can hardly be used for life assessment of the practical welded components, which depends on the loading conditions of the components.
关键词:
high temperature
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null
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null
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null
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null
Journal of Alloys and Compounds
La1-xSrxCrO3 (x=0.0 similar to 0.5) samples were prepared by the sol-gel method. The crystal structures of La1-xSrxCrO3 at room temperature all are of the othorhombic perovskite GdFeO3-type. XPS analysis indicates that chromium ions are in mixed valence state. The introduction of Sr2+ into the lattice is compensated by the oxidation from Cr3+ to Cr6+ With x increasing, the amount of Cr6+ increases. The presence of the Cr6- is one of the key factors that affect the electric conductivity of La1-xSrxCrO3. (C) 2000 Elsevier Science S.A. All rights reserved.
关键词:
rare earth;perovskite La1-xSrxCrO3;high-temperature conductivity;interconnector;XPS
