T. Imai
,
L. Geng
,
J. F. Mao and I. Tochigi 1) National Industrial Research Institute of Nagoya
,
1-1 Hirate-cho
,
Kita-ku
,
Nagoya
,
462-8510
,
Japan 2) School of Materials Science & Engineering
,
Harbin Institute of Technology
,
Harbin 15001
,
China 3) Kanagawa High-Technology Foundation
,
Kanagawa Science Park
,
3-2-1
,
Sakado
,
Takatsu-ku
,
Kawasaki
,
Kanagawa 213
,
Japan
金属学报(英文版)
β-Si3N4 whisker reinforced aluminum composites was fabricated by squeeze casting before extrusion and an effect of content of Mg on the High Strain Rate Superplastic- ity (HSRS) were investigated, The optimum temperature of the composites at which maximum total elongation is obtained decreases according to magnesium content and the β-Si_3N_4w/Al-3Mg exhibits the total elongation of about 200% at the strain rate of 10~(-1) s~(-1) and at 853-858 K, although the β-Si_3N_4w/Al-0Mg composite shows about 100% elongation at the strain rate of about 1×10~(-1) s~(-1) at 903-913 K. Optimum strain rate of the composites fabricated by squeeze casting was about 1×10~(-1) s~(-1) but TEM observation indicates that the β-Si_3N_4w/Al-Mg has a fine grain of about 2- 3μm and that the whisker might no react with Mg at the interfaces, although the β-Si_3N_4 whisker react with aluminum matrix.
关键词:
high strain rate superplasticity
,
null
,
null
LIU Guoquan Department of Materials Science and Engineering
,
University of Science and Technology Beijing
,
100083
,
China.
材料科学技术（英文）
Quantitative analysis of populations having a geometric structure,which has developed into a special scientific subject called microstructology or stereology,is of great importance to the characterization and evaluation of microstructures and their evolution in various processes.This paper, besides a brief discussion on those topics such as the recent developments of computer assisted image analysis,mathematical morphology,and fractal analysis,will mainly focus on the scope,fundamen- tals,present status,and perspectives of classical stereology.Several case examples of its application to materials science will also be given.
关键词:
stereology
,
null
,
null
,
null
N.V.Ch
,
ra Shekar
,
P.Ch.Sahu
,
K.Govinda Rajan
材料科学技术（英文）
Laser-heated diamond-anvil cell (LHDAC) is emerging as the most suitable, economical and versatile tool for the measurement of a large spectrum of physical properties of materials under extreme pressure and temperature conditions. In this review, the recent developments in the instrumentation, pressure and temperature measurement techniques, results of experimental investigations from the literature were discussed. Also, the future scope of the technique in various avenues of science was explored.
关键词:
Laser heating
,
null
,
null
,
null
Douxing LI and Hengqiang YE (Laboratory of Atomic imaging of Solids
,
Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang
,
110015
,
China)
材料科学技术（英文）
The present paper summarizes the current status of high resolution electron microscopy (HREM)and the applications of HREM to materials science and condensed matter physics. This review recounts the latest development of high resolution electron microscope, progress of HREM and the applications of HREM, including the crystal structure determination of microcrystalline materials and characterization of the local structure of the defects and nanostructured materials as well as qualitative and quantitative analysis of the grain boundaries, interfaces and interfacial reactions in the advanced materials by means of HREM in combination with electron diffraction,subnanometer level analysis, image simulation and image processing.
关键词:
