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Application of the annexation principle to the study of thermodynamic properties of ternary metallic melts In-Pb-Ag and In-Bi-Sb

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Rare Metals 2002年第2期21卷 142-151页

作者： zhang jianmetallurgical {2. school.university of Science and technology beijing, beijing 100083, china metallurgical engineering {2. University of Science and Technology Beijing 北京 100083

Based on the phase diagrams, measured activities an the annexationprinciple, the calculating models of mass action concentrations forin-Pb-Ag and In-Bi-Sb ternary metallic melts have been *** results of calculation both agree with practice, and obey the lawof mass action, showing that the models formulated can reflect thestructural reality of the corresponding melts and the annexationprinciple is applicable to the them.

关键词： activity mass action concnetration th annexation principle In-PB-Ag

Thermodynamic properties and mixing thermodynamic parameters of binary homogeneous metallic melts

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Rare Metals 2003年第1期22卷 25-32页

作者： zhang Manmetallurgical {2. school, university of Science and technology beijing, beijing 100083, china metallurgical engineering {2. University of Science and Technology Beijing 北京 100083

After the investigation on the thermodynamic properties and mixingthermodynamic parameters of binary homogeneous metallic melts involving compound, peritectic as wellas solid solution, it was found that the equations of mixing free energy DELTA G^m and excess freeenergy DELTA G^(XS) of them can he expressed by the following equations: DELTA G^m = SIGMA x [SIGMAN_i DELTA G_I^(THETA) + RT(SIGMA N_j ln N_j + SIGMA N_i ln N_i )] and DELTA G^(XS) = DELTA G^m -RT(a ln a + b ln b), respectively.

关键词： metallic melt mixing thermodynamic parameter coexistence theory activity mass action concentration

The mathematical model of wetting angle of heterogeneous nucleation

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Science china(Technological Sciences) 2004年第4期47卷 391-397页

作者： HUANG Cheng1, SONG Bo1, MAO jinghong2.& ZHAO Pei3 1. school of metallurgical and Ecological {2., university of Science and technology beijing, beijing 100083, china 2. school of Material Science, university of Science and technology beijing, beijing 100083, china 3. Central Iron and Steel Research Institute, beijing 100081, china 1. school of metallurgical and Ecological {2. University of Science and Technology Beijing 100083 Beijing China 2. school of Material Science University of Science and Technology Beijing 100083 Beijing China 3. Central Iron and Steel Research Institute 100081 Beijing China

The heterogeneous nucleation has been analyzed in terms of the thermodynamic theory, and the mathematical model of wetting angle of heterogeneous nucleation has been developed based on the dynamic requirements of hetero- and homogeneous nucleation. With the wetting angel model, the wetting angles of different catalysts in liquid iron have been calculated. The result shows that the wetting angle of most catalysts is smaller than 40, and the value of f() is far less than 1. The wetting angles of TiN, TiC and RE2.3 are smaller, while the wetting angle of MnO is bigger among the ordinary nucleation catalysts. The wetting angles calculated by this model are in agreement with the results of other research work.

关键词： heterogeneous nucleation, mathematical model, wetting angle, undercooling.

Future Trends of Deep Sea Bed Mining technology

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International journal of Minerals,Metallurgy and Materials 1999年第1期13卷 4-7页

作者： Yan Feng Haoran Li Wenming zhang (Resources engineering {2., university of Science and technology beijing, beijing 100083, china) Resources engineering school University of Science and Technology Beijing Beijing 100083 China

The present status of deep sea bed mining technology for polymetallic nodules has been critically examined in light of its history of development the UNCLoS (the United Nation Convention on the Law of the Sea) regime and the current trends in *** critical technologies have been highlighted and the need for system integration underscored. The deep sea bed environment and the engineering challenge were presented and the necessary features of the deep sea bed mining system for commercial mining was analyzed. The key accomplishments, problems and future bends in research in the development of the mining system are also discussed. Finally, it points out that the technology gaps can be filled by the bine commercial mining is undertaken as a result of market conditions in its favor.

关键词： deep sea bed mining, UNCLoS TIS (Total Integrated System), polymetallic nodules mining system

Effects of Na/K ratio on the phase structure and electrical properties of Na_xK_(1-x)NbO_3 lead-free piezoelectric ceramics

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Rare Metals 2010年第2期29卷 220-225页

作者： zhang Qian, zhang Boping, Li Haitao, and SHANG Pengpeng {2. of Materials Science and engineering, university of Science and technology beijing, beijing 100083, china school of Materials Science and engineering University of Science and Technology Beijing

Lead-free piezoelectric NaxK1-xNbO3（x = 0.3-0.8）（NKN） ceramics were fabricated by normal sintering at 1060°C for 2.*** and electrical properties of the ceramics were investigated with a special emphasis on the influence of Na *** grain size of the produced dense ceramic was decreased by increasing Na content.A discontinuous change in the space distance was found at the composition close to Na0.7K0.3NbO3 ceramic, which indicates the presence of a transitional composition between two different orthorhombic phases, which is similar to the behavior of morphotropic phase boundary（MPB） in NaxK1-xNbO3 *** MPB-like behavior contributes to the enhanced piezoelectric coefficient d33 of 12. pC/N, planar-mode electromechanical coupling coefficient kP of 2..6%, and dielectric constant εr of 703, respectively for the Na0.7K0.3NbO3 *** temperature TC and the transitional temperature TO-T from orthorhombic to tetragonal phase are observed at around 42.°C and 2.0°C, respectively.

关键词： lead-free piezoelectric ceramics NKN sintering morphotropic phase boundary(MPB)

A Fuzzy Model for Evaluating the Mining Condition of Underground Coal Mines

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International journal of Minerals,Metallurgy and Materials 1999年第4期13卷 242-245页

作者： Zhongrue Li Shaowen zhang(Resources engineering {2., university of Science and technology beijing, Beding 100083, china) Resources engineering school University of Science and Technology Beijing Beijing 100083 China

In mining industries no mines are identical and each mine has its own unique set of mining conditions. In order to study thecondition of mines for efficiency, safety and economy reasons, a fuzzy model is presented based on fuzzy evaluation. Relevant data fromfive mines were collected and the model was used to evaluate the mining condition of these mines. The evaluation results are in conformity with the real situation.

关键词： fuzzy model mining condition coal mine

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

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journal of university of Science and technology {2. 2001年第3期8卷 195-197页

作者： Lina zhang, jianxin Dong, Xishan Xie Material Science and engineering {2., university of Science and technology beijing, beijing 100083, china Univ Sci & Technol beijing Sch Mat Sci & Engn Beijing 100083 Peoples R 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

Fabrication of pure copper rods containing continuous columnar crystals by continuous unidirectional solidification technology

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journal of university of Science and technology {2. 2004年第3期11卷 240-244页

作者： Hong zhang jianxin Xie Zidong Wang Materials Science and engineering {2., university of Science and technology beijing, beijing 100083, china Mat. Sci. and Eng. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

Pure copper rods containing continuous columnar crystals were fabricatedusing the downward CUS (Continuous Unidirectional Solidification) equipment. When the technologicalparameters were set as the ranges of mould temperature 1100-1300℃, cooling distance (the distancefrom the exit of the cast mould to the start point of cooling) 10-2. mm, casting speed 0.2.2.5 mm/s,cooling water (2.-2.℃) volume 1000-132. L/h, and when these parameters matched reasonably, the CUSprocess was performed stably, and pure copper rods containing continuous columnar crystals withbright and smooth surface were produced. The dendritic arm spacing of the crystals in copper rodsdecreased with increasing the casting speed. The results of the texture by X-ray diffractionanalysis showed that the rods has strong fiber texture.

关键词： copper continuous unidirectional solidification mould temperature castingspeed microstructure texture

A phenomenological constitutive equation for Rene 95 PM alloy and its application to isothermal forging process of turbine disk

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journal of university of Science and technology {2. 2002年第4期9卷 282-286页

作者： Maicang zhang, jianxin Dong, Yanping Zeng, Xishan XieMaterials Science and engineering {2., university of Science and technology beijing, beijing 100083, china Mat. Sci. and Eng. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

The flow behavior of Rene 95 PM alloy was studied from 1050 to 1150 deg Cwith strain rate of 1 X 10^(-3), 1 X 10^(-2., 1 X 10^(-1) and 1 s^(-1). At a given temperature andstrain rate, flow curves exhibit a peak followed by flow softening up to a steady state. Moreover,at constant strain, flow stress increases with increasing strain rate and decreasing temperature. Anequation relating hyperbolic sine of flow stress to hot working parameters, such as strain, strainrate and temperature, was established by using multiple nonlinear regression method. A very goodagreement was found between predicted and experimental flow stress in all the strain rangeinvestigated. Application of the constitutive equation in predicting forming loads and flow behaviorand temperature distribution in both upper and lower dies in an isothermal forging process ofturbine disk of large dimension (about 630 mm) by means of a finite element code was systematicallyanalyzed.

关键词： constitutive equation finite element method isothermal forging Rene 95PM alloy