检索结果-南通市图书馆

Nonlinear Theory on Dynamic Controlling Interface Patterns DuringSolidification of a Dilute Binary Alloy

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and materials 1999年第4期13卷 253-258页

作者： Zidong Wang Hanqi Hu(material {1. and Engineering {2., University of {1. and technology beijing, beijing 1.0083. china) material {1. and Engineering {2. University of Science and Technology Beijing Beijing 100083 China

In non-equilibrium nonlinear region, the nonlinear equations of time dependence of perturbation amplitude at the solid/liquidinterface during solidification of a dilute binary alloy are established on the base of assuming that there is local equilibrium at the solid/liquid interface and considering that curvature, temperature and composition at the solid/liquid interface which are related to the perturbation amplitude are nonlinear. As a result, patterns at the solid/liquid interface during solidification process, which is from nonsteadystate to steady state can be controlled by these nonlinear equations.

关键词： nonlinearity solidification, dilute binary alloy, dynamic control

Analysis for twinning and slip in face-centered cubic crystals under axisymmetric co-deformation

在线全文

学校读者我要写书评

暂无评论

science {1.(Technological sciences) 2006年第5期49卷 521-536页

作者： CHEN Zhiyong1,2. CAI Hongnian1, ZHANG Xinming2. WANG Fuchi1 & TAN Chengwen1,3 1. school of material {2. and Engineering, beijing Institute of technology, beijing 100081, china 2. school of material science and Engineering, Central South University, Changsha 410083, china 3. school of material {2. and Engineering, beijing University of Aeronautics and Astronautics, beijing 1.0083. china school of {1. {2. and Engineering Beijing Institute of Technology Beijing China school of {1. {2. and Engineering Central South University Changsha China school of {1. {2. and Engineering Beijing University of Aeronautics and Astronautics Beijing China

The maximum work principle of Bishop-Hill was developed to analyze the axisymmetric co-deformation in face-centered cubic crystals (f.c.c.) for twinning on {111} 112.and slip on {111} 110 systems. The influence of ξ , the ratio of critical re- solved shear stress for twinning to slip, on the yield stress states and corresponding active slip or/and twinning systems for orientations in the standard stereographic triangle of cubic crystal was investigated systematically. The Taylor factors and the anisotropy of yield strength for three important orientations [100], [110] and [111] in orientation space were analyzed. It is found that the yield strength asymmetry for the case of axisymmetric de- formation of tension and compression can be explained based on the microscopic theory of crystal plasticity. The concept of orientation factor for twinning ability was proposed and the deformation mechanism map in the orientation space was established for the case of axisymmetric deformation. The deformation texture formation and development of f.c.c. crystals with low stacking fault energy for axisymmetric tension can be explained qualita- tively on the basis of analyzed results.

关键词： twinning slip face-centered cubic crystals axisymmetric co-deformation Bishop-Hill maximum work principle yield strength anisotropy

Relationship between Low Temperature Toughness and Microstructure in Low Activation Fe-Cr-Mn(W,V)Steel for Fusion Reactors

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and materials 1999年第2期13卷 111-115页

作者： Benfu Hu Chengchang jia(material {1. and Engineering {2., University of {1. and technology beijing, beijing 1.0083. china) material {1. and Engineering {2. University of Science and Technology Beijing Beijing 100083 China

Fe-Cr-Mn (W, V) austenite steel was researched in order to supply a theory base for the first wall materials of fusion *** included vacuum melting, forging, annealing, solution treatment, Charpy impact tests and microstructure observation. Theresults show that the imped value decreases with the test temperature decreasing. In this system, there is ductile/brittle transition. Themechanism of this decrease of the impact value is considered to be due to γ - ε transformation in sub-stable austenite steel and stoppingoverlapping sacking fault by grain boundaries in stable austenite steel.

关键词： fusion reactor first wall materials low temperature toughness Fe-Cr-Mn system

Annealing Texture Evolution of Ti-IF Steel during Batch Annealing

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and materials 1998年第3期12卷 175-179页

作者： Jing Shi Xianjin Wang(material {1. and Engineering {2., University of {1. and technology beijing, beijing 1.0083. china) material {1. and Engineering {2. University of Science and Technology Beijing Beijing 100083 China

Texture development and recrystallization behavior of Ti-IF steel during Batch Annealing (BA) were investigared with X-ray diffraction and EBSP in lab, and the results were compared with research work on continu ous annealing (CA) with rapid heating rate. The basic tendencies are similar that eary nucleation takes place in 1.1.ND fibers, 1.0>RD fibers are consumed at the end of recrystallization, and 1.1.ND texture dominates over annealing texture. However, the detailed texture transformation during batch annealing is different and somewhat more compicated than tha in rapid-heating process. Moreover, misorientation plays an important role in texture transformation of BA In addition, the results of EBSP are consistent with that of ODF well.

关键词： Ti-IF steel texture batch annealing X-ray diffraction EBSP

Phenomenological Modeling of Warm Compaction and Experimental Verification

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and materials 2000年第4期14卷 292-295页

作者： Shiju Guo, Tao Lin (material {1. and Engineering {2., University of {1. and technology beijing, beijing 1.0083. china) material {1. and Engineering {2. University of Science and Technology Beijing Beijing 100083 China

A phenomenological modeling approach to establishing the warm compaction equation and curves by modifying the regression equation of the room-temperature compaction curve is presented. An enhanced factor of compacting pressure is introduced into the equation in order to reveal the effects of powder/die temperature and filling height of powders on green density. Compaction curves yielded from this equation are consistent with the experimental data of ATOMET grade iron powders. The curves show that the powder/ die temperature should reduce as the filling heights of powders increase and that in some cases warm compaction can not give rise to a higher green density.

关键词： powder metallurgy warm compaction compaction equation materials

Development and Application of High Performance X80 Line Pipe for the 2.(nd) West-East Gas Pipeline

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2011年第S1期18卷 39-48页

作者： LI He-lin 1 , HUO Chun-yong 1 , JI Ling-kang 1, 2., LI Yang 1, 3 (1. CNPC Tubular Goods Research Institute, Xi’an 710065, china 2. . school of {2. science and Engineering, Xi’an Jiaotong University, Xi’an 710049, china 3. school of {2. science and Engineering, University of science and technology beijing, beijing 1.0083. china) CNPC Tubular Goods Res Inst Xian 710065 Peoples R China Xi An Jiao Tong Univ Sch Mat Sci & Engn Xian 710049 Peoples R China Univ Sci & Technol beijing Sch Mat Sci & Engn Beijing 100083 Peoples R China

It is the development tendency of gas pipeline to improve strength of line pipe and transmission pressure, which is an important symbol of the progress of gas pipeline technology. The {1.d West-East Gas Pipeline (the {1.nd WEGP) is the largest-scale X80 high pressure gas pipeline project in the world. Through the joint development project by Pipeline Company, research institute, and steel company, a series of achievements of technology have been obtained, which makes it possible to apply pressure of 1.1.MPa and X80 LSAW and HSAW pipe for the {1.nd WEGP. Specifications of X80 steel and pipe have been issued based on API 5L. High performance X80 steel and pipe have been developed and meets the Specification. General design conception of applying HSAW pipe and LSAW pipe on gas transmission trunk line with large diameter and high pressure has been established. Failure control of the {1.nd WEGP has been carried out to avoid failure and reduce the lost which based on analysis of pipeline failure mode. In this paper, research and development of high performance X80 welded pipe, establishment of technical route of joint application of HSAW and LSAW steel pipe and key technology of failure control are emphatically discussed.

关键词： 2.nd WEGP acicular ferrite failure control arrest toughness strain-based design

Microstructure Evolution of Semi-solid Processed Hyper-eutectic Al-30%Si Alloy

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and materials 1999年第4期13卷 259-261页

作者： Yanjun Li Weimin Mao Xueyou Zhong(material {1. and Engineering {2., University of {1. and technology beijing, beijing 1.0083. china) material {1. and Engineering {2. University of Science and Technology Beijing Beijing 100083 China

An investigation was made on the influences of mechanical stirring on microstructure of hyper-eutectic Al-30%Si alloy (inmass fraction) during solidification. The primary Si crystals formed in the alloy melt were gradually changed from elongated platelets tonear-spherical shapes by mechanical stirring. The spheroidization of primary St crystals occurs by the mechanism of bending and fractureof Si platelets, wear and collision between Si crystals, and coalescence of small Si particles. The influence of under-cooling and coolingrate of the alloy melt on primary Si crystals of semi-solid processed alloys is investigated as well. The increase of under-cooling andcooling rate decreases the size of primary Si crystals.

关键词： semi-solid state process solidification structure mechanical stirring hyper-eutectic Al-Si alloy

A New Process for Preparing Fine-ceramic-containing Composite Coatings──Flame Spray Synthesis

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and materials 2000年第3期14卷 214-217页

作者： Changsong Liu, Jihua Huang, Sheng Yin (material {1. and Engineering {2., University of {1. and technology beijing, beijing 1.0083. china) material {1. and Engineering {2. University of Science and Technology Beijing Beijing 100083 China

Flame spray synthesis (FSS), a combination of the flame spray technology and Self-propagation High-temperature Synthesis (SHS) was developed for preparing fine-ceramic-containing composite coatings. It can simplify the preparations of powder to synthesize and deposit the desired {1.s in one step. The preliminary results obtained from TiC-Fe cermet coatings by FSS process are reported. The peculiar microstructure of the composite coatings, which contains very fine (1.) and round TiC and alternate TiC-rich (Hv=1.€*1.GPa) and TiC-poor layers (Hv=3.0 -6.0GPa), is expected to play an important role in their tribological properties.

关键词： Self-propagation High-temperature Synthesis (SHS) flame spray flame spray synthesis (FSS) TiC-Fe cermet coating

SEM in-situ Fatigue Observation on Crack Initiation and Growth from Inclusion in P/M Rene95 Superalloy

在线全文

学校读者我要写书评

暂无评论

Journal of University of science and {1. {2. 2001年第3期8卷 195-197页

作者： Lina Zhang, Jianxin Dong, Xishan Xie material {1. and Engineering {2., University of {1. and technology beijing, beijing 1.0083. china material {1. and Eng. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

A special designed experiment was conducted for observing crack initiation and growth in P/M Rene95 superalloy under tension-tension loading by self-made SEM in-situ fatigue loading stag. Several alumina inclusion particles exposed at the specimen surface were observed carefully. During fatigue test inclusions led to cracks initiation. The cracks can be formed by two mechanisms. Generally, the cracks nucleated at the interface between inclusion and matrix. Sometimes, cracks were also formed inside the inclusion. As the increase of cycles, some cracks at the interface between inclusion and matrix broadened and propagated along the direction about 45 degrees to the loading axis. On the other hand, the cracks inside the inclusion propagated in the inclusion and towards matrix.

关键词： inclusion P/M superalloy LCF SEM in-situ fatigue