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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 school 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 122 pC/N, planar-mode electromechanical coupling coefficient kP of 28.6%, 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 420°C and 200°C, respectively.

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

Adhesion of NiCu Films DC Biased Plasma-Sputter-Deposited on MgO (001)

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International Journal of Minerals,Metallurgy and Materials 2000年第3期14卷 218-221页

作者： Hong Qiu, Mituru Hashimoto ( beijing Keda-Tianyu Microelectronic Material technology Development Corporation, beijing 100083, china Applied science school, university of science and technology beijing, beijing 100083, china Department of Applied Phys beijing Keda-Tianyu Microelectronic Material technology Development Corporation Beijing 100083 China Applied science school University of Science and Technology Beijing Beijing 100083 China Department of Applied Physics and Chemistry University of Electro-Communications 1-5-1 Chofugaoka Chofu-shi Tokyo 182-8585 Japan

NiCu films about 60nm thick were deposited on MgO (001) substrates at 230℃ by DC plasma-sputtering at 2.7kV and 8mA in pure Ar gas using a Ni90Cu10 target. A DC bias voltage of 0, 60, 110 or 140V was applied to the substrate during deposition. The adhesion of the film to the substrate was studied using a scratch test as a function of . The application of is very effective in increasing the adhesion of the film to the substrate. In conclusion, the adhesion increases with cleaning the substrate surface by sputtering off impurity admolecules during the film initial formation due to the energetic Ar ion particle bombardment.

关键词： NiCu film plasma-sputter-deposition negative bias voltage adhesion

Electro-Pulse on Improving Steel Ingot Solidification Structure

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International Journal of Minerals,Metallurgy and Materials 1999年第2期13卷 94-96页

作者： Yong Tang Jianzhong Wang Daqing Cang(Metallurgy school, university of science and technology beijing, beijing 100083, china) Metallurgy school University of Science and Technology Beijing Beijing 100083 China

Pulse Electric Discharging (PED) is a novel technique that can modify solidifying structure and reduce grain size. ItS effectsapplied to the high carbon liquid steel were presented here. The macrostructure and microstructure of the high carbon alloy steel werealso observed. Results show that (1 ) the length of columnar crystal at the edge of ingot without PED treatment is much longer than thatwith PED, and (2) the perlite lamellae of steel billets after deposed by PED are twisted and shortened. An explanation of those experimental results is given.

关键词： electro-pulse solidification structure steel ingot

Change Laws of Flake's Temperature during Making a Diamond Film by DC-PJ

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International Journal of Minerals,Metallurgy and Materials 1999年第2期13卷 97-102页

作者： Xuhong Chen Lihe Zhao Fanxiu Lu(Mechanical Engineering school, university of science and technology beijing, beijing 100083, china) Mechanical Engineering school University of Science and Technology Beijing Beijing 100083 China

When making a diamond film by direct current plasma jet, a kind piece of flake is used as a base body Which the film can beattached to. The flake's temperature is unstable. Therefore, some experiments and constructed mathematical models, which were solvedby computer, were done. The results show that the flake's temperature is influenced by many factors and the mains are plasma jet powerand vacuum pressure. Through adjusting the two parameters, the flake's temperature can be accurately controlled, furthermore, diamondfilms' quality would be improved. Lowering sediment platform's temperature has a little effect to the flake's temperature at present technology conditions.

关键词： CVD (Chemical Vapor Deposition) plasma, impact heat transfer

Solubility of Ba in Liquid Iron and Interaction Effect of the Third Elements

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International Journal of Minerals,Metallurgy and Materials 2000年第2期14卷 82-85页

作者： Bo Song Qiyong Han Chenming Zhang(Metallurgy school, university of science and technology beijing, beijing 100083, china) Metallurgy school University of Science and Technology Beijing Beijing 100083 China

Experiments were carried out at 1873 K in a double-temperature zone furnace using vapor pressure method. The equilibriumtests of bedum vapor with liquid iron were conducted in CaO crucibles sealed in a Mo chamber. As a result, the experiments obtainedthe relation between the dissolved content of Ba in liquid iron and the vapor pressure of Ba and the standard Gibbs energies for the re-actions Ba(g)=[Ba] and Ba(l)=[Ba].

关键词： Ba dissolution equilibrium liquid iron interaction parameter

An Improved Artificial Neural Network Model for Predicting Silicon Content of Blast Furnace Hot Metal

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International Journal of Minerals,Metallurgy and Materials 2000年第4期14卷 269-272页

作者： Bin Yao, Tianjun Yang, Xiaojun Ning (Metallurgy school, university of science and technology beijing, beijing 100083, china) Metallurgy school University of Science and Technology Beijing Beijing 100083 China

Based on the skills of initializing weight distribution, adding an impulse in a neural network and expanding the ideal of plural weights, an artificial neural network model with three connection weights between one and another neural unit was established to predict silicon content of blast furnace hot metal. After the neural network was trained in the off-line state on the basis of a large number of practical data of a commercial blast furnace and making many learning patterns, satisfactory testing and simulating results of the model were obtained.

关键词： blast furnace silicon content neural network Metallurgy

Design and Synthesis of Ti-ZrO_2 Functionally Graded Materials

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Journal of university of science and technology beijing 2001年第1期8卷 48-52页

作者： Lidong Teng, Fuming Wang, Wenchao Li Metallurgy school, university of science and technology beijing, beijing 100083, china Univ Sci & Technol beijing Met Sch Beijing 100083 Peoples R China

Functionally graded materials (FGMs) based on titanium-zirconia system have been prepared by powder metallurgical method. The graded interlayer number and the compositional distribution have been designed by elastic finite element method. The interfacial microstructure between layers, the combining state of phases between Ti and ZrO2 have been investigated by means of XRD (X-ray diffraction), SEM (scanning electron microscope), EDS (energy dispersive spectrometer) and so on. The co-existing region of Ti and ZrO2 has been determined by thermodynamic calculation to control the sintering atmosphere. The experimental results show that the joint between Ti and ZrO2 phases is physical in this composite and ZrO2 mainly exists as tetragonal phase. The microstructure of Ti-ZrO2 system FGM exhibits a transition from a zirconia particle dispersion in a titanium matrix to an inverse dispersion of titanium in zirconia. The gradient structure of titanium and zirconia can relieve thermal stress.

关键词： Ti-ZrO2 system functionally graded material thermodynamic analysis finite element method

Physical Property Influence on Foaming Index of Refining Slag

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International Journal of Minerals,Metallurgy and Materials 1999年第1期13卷 8-10,14页

作者： Lin Di Ping Wang Jie Fu (Metallurgy school, university of science and technology beijing, beijing 100083, china) Univ of science and technology Beijing Beijing China

The foaming indexes of a group of refining slag were measured. The refining slag with better foaming ability was chosen,its composition (mass frachon in %) is CaO, 53.25, SiO2, 17.75, MgO, 9; Al2O3, 15 and CaF2, 5. The relationship between slag foaming index and physical properties of the slag was obtained by dimensional analysis, and the expression indicates that viscosity of slag is the most important factor which influences foamng index. The influence sequence of slap composition on foaming index was also obtained as follows: CaF2→MgO→Al2O3→ B (CaO/SiO2).

关键词： secondary refining submerged arc slag dimensional analysis

Behaviors of fine bubbles in the shroud nozzle of ladle and tundish

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Journal of university of science and technology beijing 2003年第4期10卷 20-23页

作者： Yanping Boo, Jianhua Liu, and Baomei XuMetallurgical Engineering school, university of science and technology beijing, beijing 100083, china Metall. Eng. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

Fine bubbles will create when the inert gas is introduced to the high rapidsteel stream within the shroud nozzle between ladle and tundish. The collision and attachment amongthe bubbles and fine inclusions will promote the floatation efficiency of inclusions in the *** behaviors of the bubbles, such as the dispersion in shroud, coalescence and floatation intundish, are studied. The results show that the maximum sizes of the bubbles in the water and steelflow within the shroud in the length of 1.2 m are 0.70-1.44 mm and 1.53-3.16 mm respectively whenthe flow rates are 0.006-0.016 m^3/s; the terminal velocities of fine bubbles in the water andmolten steel within the tundish are 0.02-0.2 and 0.05-0.6 m/s.

关键词： fine bubbles shroud nozzle of the ladle flotation

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 beijing 2002年第4期9卷 282-286页

作者： Maicang Zhang, Jianxin Dong, Yanping Zeng, Xishan XieMaterials science and Engineering school, 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