Y. Huo
,
Y. Chen
,
X. Zu and M. Tu( Department of Metal Materials
,
Sichuan University
,
Chengdu 610065
,
China)( Department of Metal Materials
,
Sichuan University
,
Chengdu 610065
,
China)( Department of Metal Materials
,
Sichuan University
,
Chengdu 610065
,
China)( Department of Physics
,
Sichuan University
,
Chengdu 610065
,
China)
金属学报(英文版)
In this paper, a theoretical model was presented to simulate the stress-strain hysteresis and the inner hysteretic behaviors, which were observed for polycrystalline Ni-Ti and Cu-based shape memory alloys (SMAs) at various temperatures. It was assumed that the stress-strum hysteresis of the grains of a polycrystalline sample of SMAs was relatively simple and easy to be calculated. The texture of the sample was characterized by a distribution function, which could be obtained from the experiments. Thercfore,the model provided a means to simulate and, for the first time, to predict the stressstrain hysteresis at different loading temperatures for polycrystalline SMAs.
关键词:
shape memory alloys (SMAs); hysteresis; mathematical modeling of phase transition
Shaoxiong ZHOU
材料科学技术（英）
The discovery of the first Fe-based ferromagnetic amorphous alloy in 1966 had made an impact on conventional magnetic materials because of its unique properties. Since then, a number of amorphous magnetic materials have been successfully developed and used in a wide variety of applications. A brief review of R & D activities on amorphous soft magnetic materials in China is given from the beginning to the present in a somewhat chronological order, followed by a brief introduction to their applications on electric and electronic industries. An analysis and a prospect of Chinese market of such amorphous materials are also presented.
关键词:
QIAO Lijie LIU Rui XIAO Jimei University of Science and Technology Beijing
,
Beijing
,
China
金属学报(英文版)
The effects of stress components on nucleation sites and propagation directions of stress cor- rosion cracks in brass were investigated with specimens under mode Ⅱ and mode Ⅲ loadings. The results indicated that under mode Ⅱ loading,stress corrosion cracks nucleated on the site with maximum normal stress component and propagated along the plane perpendieular to the maximum normal stress,under mode Ⅲ loading,the stress corrosion crack was not evident on the 45°plane due to the general corrosion in aqueous solution with high NH_4OH concentra- tion,while stress corroded in aqueous solution with low NH_4OH concentration, numerous cracks with spacings of 10—150μm were found on the 45°plane with maximum normal stress and no stress corrosion cracks was observed on the plane with maximum shear stress.
关键词:
stress corrosion cracking
,
null
,
null
,
null
Transactions of Nonferrous Metals Society of China
A simplified model was proposed targeting at the isotropic high porosity metal materials with well-distributed structure. From the model the mathematical relationship between elongation and porosity was deduced for those materials, and the relationship formula was derived generally for actual high porosity metals at last, whose validity is supported by the representative experiment on a nickel foam prepared by electrodeposition.
关键词:
high porosity metal material;elongation;porosity
Science in China Series E-Technological Sciences
A geometrical model has been established based on the structure feature of high porosity metal materials, the mathematical relationship between electrical resistivity and porosity for high porosity materials with even structure has then been deduced conveniently, and the formula for calculating the electrical resistivity of high porosity materials through porosity, which is easy to know, has been acquired further. Besides, the theoretical formula was verified to coincide with the test results well by the application taking nickel foam as an example.
关键词:
high porosity material;electrical resistivity;calculation formula;deduction;foams
P.Verma
,
O.P.P
,
ey
,
A.Verma
材料科学技术（英）
In the present work investigations have been made to see the role of metal oxides on the performance of the silver metal oxides electrical contact materials. Silver metal oxide materials of three different compositions Ag-10CdO, Ag-7.6SnO2-2.3In2O3 and Ag-10ZnO were prepared by internal oxidation process under identical processing conditions. These materials were tested for electrical conductivity, hardness, and erosion loss. Performing an accelerated test on the actual contactor assessed the electrical performance, involving erosion loss and temperature rise of the processed materials. The arc-eroded surface was characterized under scanning electron microscope. The study of the eroded surfaces of contacts indicates that the thermal stability of metal oxides depends on nature of silver-metal oxide interface and their mode of erosion. An attempt is made to correlate the surface features of the eroded contacts with the thermal stability of metal oxides.
关键词:
Contact material
,
null
,
null
Zhenfang LIAO
,
Shijin ZHANG
材料科学技术（英）
Electro-hydraulic impulse water-air mixing jet by which the quality of metal materials can be improved is described in this paper. The experimental results proved that the hardness and the micro-hardness of the surface layer of metal materials can be improved with this method, for example, the microhardness of CrWMn can be increased by 35.62 percent.
关键词:
Electro-hydraulic impulse
,
null
,
null
CAI Jiuju
,
LU Zhongwu
,
YUE Qiang
钢铁研究学报(英文版)
The industrial system should learn from the natural ecosystem. The resource utilization efficiency should be increased and the environmental load should be decreased, depending on the materials recycled in the system. The classification of industrial materials from the viewpoint of largescale recycling was stated. Recycling of materials, on three different levels, was introduced in the industrial system. The metal flow diagram in the life cycle of products, in the case of no materials recycled, materials partially recycled, and materials completely recycled, was given. The natural resource conservation and the waste emission reduction were analyzed under the condition of materials completely recycled. The expressions for the relation between resource efficiency and material recycling rate, and the relation between ecoefficiency and material recycling rate were derived, and the curves describing the relationship between them were protracted. The diagram of iron flow in the life cycle of iron and steel products in China, in 2001, was given, and the iron resource efficiency, material recycling rate, and iron ecoefficiency were analyzed. The variation of iron resource efficiency with the material recycling rate was analyzed for two different production ratios.
关键词:
recycling;industrial material;product life cycle;resource efficiency;ecoefficiency;material recycling rate
