TAN YiDalian University of Technology
,
Dalian
,
ChinaSHINODA THitachi Research Laboratory
,
Hitachi Ltd. 391-12 Hitachi
,
JapanMISHIMA YTokyo Institute of Technology
,
Nagatuta. Midori-Ku
,
Yokohama 227
,
JapanSUZUKI TDepartment of Metallurgical Engineering
,
Tokyo Institute of Technology. Ookayama
,
Meguro-Ku
,
Tokyo 152
,
Japan
金属学报(英文版)
The effects of boron addition on defect hardening at room temperature and on high temperature creep properties are investigated in the B2 NiAl intermetallic compound. It is found that boron addition is effective on increasing the room temperature hardeness on the Ni-rich side but it has no effect on the A1-rich side of stoichiometry. These observations are attributed to interstitial dissolution of boron in Ni-rich NiAl and to a lack of solubility and also due to an enrichment at grain boundaries on the A1-rich side. The similar effect is found in high temperature creep resistance of NiAl by boron addition. The high temperature creep resistance increases on the Ni-rich side but it does not affect the A1-rich side of off-stoiciometry.
关键词:
Andrej Atrens
材料科学技术（英文）
Corrosion research by Atrens and co-workers has made significant contributions to the understanding of the service performance of engineering materials. This includes: (1) elucidated corrosion mechanisms of Mg alloys, stainless steels and Cu alloys, (2) developed an improved understanding of passivity in stainless steels and binary alloys such as Fe-Cr, Ni-Cr, Co-Cr, Fe-Ti, and Fe-Si, (3) developed an improved understanding of the melt spinning of Cu alloys, and (4) elucidated mechanisms of environment assisted fracture (EAF) of steels and Zr alloys. This paper summarises contributions in the following: (1) intergranular stress corrosion cracking of pipeline steels, (2) atmospheric corrosion and patination of Cu, (3) corrosion of Mg alloys, and (4) transgranular stress corrosion cracking of rock bolts.
关键词:
Stress corrosion cracking
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null
,
null
Zheng FANG
,
Quanru ZHANG
,
Hengzhong ZHANG
,
Yuan FANG
材料科学技术（英文）
The thermoelectrochemistry (TEC), a novel cross discipline, is presented, including the basic equations for a cell and a half-cell reaction, the treatment of experimental data and its application to electro-generative leaching of mineral and to measuring thermodynamic and kinetic data of an electrode reaction. The TEC technology will play an important part in the research on the metallurgical process under various fields.
关键词:
Materials Science & Engineering C-Biomimetic Materials Sensors and Systems
Bamboo, one of the strongest natural structural composite materials, has many distinguishing features. It has been found that its reinforcement unit, hollow, multilayered and spirally-wound bast fiber, plays an extremely important role in its mechanical behavior. In the present work, on the basis of the study on bamboo bast fiber and wood tracheid, a biomimetic model of the reinforcing element, composed of two layers of helically wound fiber, was suggested. To detect the structural characteristics of such a microstructure, four types of macro fiber specimens made of engineering composites were employed: axially aligned solid and hollow cylinders, and single- and double-helical hollow cylinders. These specimens were subjected to several possible loadings, and the experimental results reveal that only the double-helical structural unit possesses the optimum comprehensive mechanical properties. An interlaminar transition zone model imitating bamboo bast fiber was proposed and was verified by engineering composite materials. In our work, the transition zone can increase the interlaminar shear strength of the composite materials by about 15%. These biomimetic structural models can be applied in the design and manufacture of engineering composite materials.
关键词:
bamboo;bast fiber;biomimetics;engineering composites
Science
Strengthening materials traditionally involves the controlled creation of internal defects and boundaries so as to obstruct dislocation motion. Such strategies invariably compromise ductility, the ability of the material to deform, stretch, or change shape permanently without breaking. Here, we outline an approach to optimize strength and ductility by identifying three essential structural characteristics for boundaries: coherency with surrounding matrix, thermal and mechanical stability, and smallest feature size finer than 100 nanometers. We assess current understanding of strengthening and propose a methodology for engineering coherent, nanoscale internal boundaries, specifically those involving nanoscale twin boundaries. Additionally, we discuss perspectives on strengthening and preserving ductility, along with potential applications for improving failure tolerance, electrical conductivity, and resistance to electromigration.
关键词:
strain-rate sensitivity;stacking-fault energy;nano-scale twins;cu-al;alloys;nanocrystalline metals;mechanical-properties;activation;volume;copper;deformation;behavior
YUAN Zhangfu
,
YANG Xiao
,
LU Zhixing
,
HUANG Jiangning
,
PAN Yifang
,
MA Enxiang
钢铁研究学报(英文版)
A doubleparameter oxygen lance used in a 300 t converter was designed to improve the metallurgical performance. A smallscale measurement of the jet behavior was done using a computer controlled scanning system. The experimental data on the velocity distribution at the jet centerline, the contour map of the jet velocity, the deviation of the jet centerline, and the velocity distribution of the axial section were compiled. According to the results of the smallscale measurement, the doubleparameter lance was also employed for a BOF experiment. The metallurgy indexes show that the metallurgical performance was highly promoted by use of the doubleparameter lance.
关键词:
oxygen lance;jet behavior;BOF;metallurgical performance
Biomedical Materials
In this work, porous magnesium (Mg) with a three-dimensional open-cellular structure, potentially employed as bone tissue engineering scaffolds, was fabricated by the mechanical perforation method. The influences of porosity, pore size and pore arrangement on compressive behavior and the anisotropy of new porous Mg were analyzed theoretically using orthogonal arrays and the finite element method (FEM). The results showed that the parameters of porosity, pore size and pore arrangement had different effects on the compressive properties. The compressive strength could be improved by optimizing these parameters. The anisotropy of porous Mg was also verified in this study. The theoretical results showed good agreement with the experimental ones before the strain reaches 0.038.
关键词:
unidirectional solidification;pore-size;hydroxyapatite;replacement;cartilage;porosity;matrix
MU Lin
,
JIANG Xin
,
GAO Qiang-jian
,
WEI Guo
,
SHEN Feng-man
钢铁研究学报(英文版)
Abstract： Hydrogen-enrich iron making process is certainly to be an effective method to reduce greenhouse gases emission. However, the effect of hydrogen addition on the low temperature metallurgical property of sinter is still unclear. A detailed investigation was performed on the above topic. The results are as follows. When CO is partially replaced by H2, the RDI＜315 (RDI＜28) of sinter decreases with the increase of the H2 content; when the content of H2 increases, the CO, CO2 and N2 decrease proportionally, in this case, RDI＜315 (RDI＜28) of sinter increases with the increase of H2 content; the value of RDI＜315 (RDI＜28) basically depends on the reduction index (Ri).The experimental data of RDI＜28 based on Japanese industrial standard (JIS) are a little higher than the data of RDI＜315 based on Chinese industrial standard (CIS) in the same condition. In addition, for part of CO is replaced by H2: RDI＜28=338394+11585 RDI＜315; for other gases, except H2, are decreased proportionally: RDI＜28=1739678+042922 RDI＜315.
关键词:
Key words: sinter
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hydrogen
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reduction disintegration index (RDI)
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metallurgical property
