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Relationship between powder characteristic and internal oxidation of Al in Cu-Al pre-alloyed powders

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Acta Metallurgica Sinica(English Letters) 2009年第1期22卷 71-80页

作者： Shuhua liang Xianhui WANG liang fang Zhikang FAN Department of Materials Science and Engineering Xi＇an University of Technology Xi＇an 710048 China State Key Laboratory for Mechanical Behavior of Materials Xi＇an Jiaotong University Xi＇an 710049 China

Since Cu-Al powder characteristics have important effects on the preparation of Cu/Al2O3 composite, the apparent activation energy of Al internal oxidation reaction in Cu-Al pre-alloyed powders with different characteristics was calculated in the present investigation. The microstructure and properties of the synthesized Cu/Al2O3 were studied. The results show that high-energy milling can obviously promote internal oxidation of Al in Cu-Al powders in the same solid solubility. At the same milling conditions and internal oxidation parameters, the solid solution of Al in Cu either in low or high amount will result in the poor microstructure and properties of the Cu/Al2O3 composite. Subsequently, when high-energy milling and internal oxidation are synchronously used to prepare the Cu/Al2O3 composite, there should be an appropriate solubility and milling effect for the pre-alloyed powders.

关键词： Powder characteristic Internal oxidation Cu/Al2O3 composite material Solid solution Reaction rate

Critical Temperature Characteristics of Layered High-Temperature Superconductor Under Pressure

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Communications in Theoretical Physics 2009年第4期51卷 761-764页

作者： liang fang-Ying Institute of Science and Technology for OPTO-Electronic Information of Yantai University Yantai 264005 China

We consider a Ginzburg-Landau modified model of layered high-temperature superconductor under pressure. We have theoretically studied the relation between the pressure and the temperature of layered high-temperature superconductor. If the pressure is not a constant, we have a relation of quadratic equation between the pressure and the temperature of layered high-temperature superconductor. In a special case, we find the critical temperature decreases with further increasing pressure. In another special ease, the critical temperature increases with further increasing pressure.

关键词： pressure effects transition temperature variations layered superconductor

Abrasive Wear Mechanisms of Sand Particles Intruding into ATM Roller-scraper Tribosystem

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Chinese Journal of Mechanical Engineering 2011年第5期24卷 905-910页

作者： WU Tonghai DIAO Dongfeng fang liang Theory of Lubrication and Bearing Institute Xi＇an Jiaotong University Xi＇an 710049 China Post-doctoral Research Center of Material Science and Engineering Xi＇an Jiaotong University Xi＇an 710049 China

The roller-scraper tribosystem of automatic teller machine（ATM） plays an important role in reliable cash ***,the abrasive wear of the polymer tribosystem becomes a prominent problem when operating in sandy *** wear behavior of the tribosystem in a simulated sandy environment has been experimentally studied *** the abrasive wear mechanism of roller-scraper tribosystems is still unknown to new *** wear rates of polymer rollers were examined comprehensively and several jumping variations were found in the full data *** wear stages were classified by the magnitude of wear rates,and different dominant wear mechanisms corresponding with different particle diameter were found by examining the worn *** a presumption was proposed that wear mechanisms in different stages were correlated with sand particles of different *** a verification experiment,three typical wear mechanisms including cutting,ploughing,and wedging were found corresponding with different wear stages by scanning electron microscope（SEM） examination.A theoretical analysis was carried out with a simplified sphere particle intrusion model and the transfer conditions for different wear mechanisms were studied referring to the slip-field *** a main result,three typical wear models versus friction coefficient of particle/roller,and particle radius were mapped with variant hardness of the polymer roller and ratio of contact shear stress to bulk shear *** result illuminated the abrasive wear mechanism during particle ***,the critical transition conditions gave the basis for improving the wear performance of roller-scraper tribosystems in a sandy environment.

关键词： tribosystem abrasive wear mechanism

NUMERICAL INVESTIGATION OF CAVITATION PERFORMANCE OF SHIP PROPELLERS

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Journal of Hydrodynamics 2012年第3期24卷 347-353页

作者： ZHU Zhi-feng fang Shi-liang Key Laboratory of Underwater Acoustic Signal Processing Ministry of Education Southeast University Nanjing 210096 China School of Electrical Engineering and Information Anhui University of Technology Maanshan 243002 China Key Laboratory of Underwater Acoustic Signal Processing Ministry of Education Southeast University Nanjing 210096 China

The cavitation performance of propellers is studied based on viscous multiphase flow theories. With a hybrid grid based on Navier-Stokes （N-S） and bubble dynamics equations, some recent validation results are presented in this paper in the predictions of the thrust, the torque and the vapor volume fraction on the back side of propeller blade for a uniform inflow. The numerical predictions of the hydrodynamic performance and the sheet cavitation under several operating conditions for two propellers agree with the corresponding measured data in general. The thrust and the torque are plotted with respect to the advance rate and the cavitation number. The cavitation performance breakdown is closely related to the strong sheet cavitation around propellers. The models with parameters modified are shown to predict the propeller cavitation well.

关键词： cavitation Reynolds-Averaged Navier-Stokes (RANS) propeller sliding mesh multiphase flow

Airfoil design optimization based on lattice Boltzmann method and adjoint approach

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Applied Mathematics and Mechanics(English Edition) 2018年第6期39卷 891-904页

作者： Xiaowei LI liang fang Yan PENG Research Institute of Unmanned Surface Vehicles Engineering Shanghai University Shanghai Institute of Applied Mathematics and Mechanics Shanghai University

We present a new aerodynamic design method based on the lattice Boltzmann method （LBM） and the adjoint approach. The flow field and the adjoint equation are numerically simulated by the GILBM （generalized form of interpolation supplemented LBM） on non-uniform meshes. The first-order approximation for the equilibrium dis- tribution function on the boundary is proposed to diminish the singularity of boundary conditions. Further, a new treatment of the solid boundary in the LBM is described par- ticularly for the airfoil optimization design problem. For a given objective function, the adjoint equation and its boundary conditions are derived analytically. The feasibility and accuracy of the new approach have been perfectly validated by the design optimization of NACA0012 airfoil.

关键词： lattice Boltzmann method (LBM) adjoint approach boundary treatment aerodynamic design optimization

Density of Liquid Steel over Temperature Range of 1803-1873K

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Journal of Iron and Steel Research International 2004年第3期11卷 37-40页

作者： XIAO Feng fang liang Chongqing Institute of Technology

The density of three kinds of liquid steel was measured by a modified sessile drop method over the temperature range of 1803-1 873 *** is found that the density of liquid steels decreases with increasing temperature and carbon content in *** of the density and its absolute temperature coefficient of studied steels are smaller than the literature values of pure *** molar volume of the steels increases with increasing temperature.

关键词： liquid steel density modified sessile drop method molar volume

Density of Na2O-Li2O-SiO2-B2O3 Molten Slag at 1 803-1 873K

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Journal of Iron and Steel Research International 2004年第4期11卷 15-18页

作者： XIAO Feng fang liang Chongqing Institute of Technology

The structural changes and reduction degree of chromite ore in blast furnace were studied by optical micrograph analysis, scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDXA). The smelting re... 详细信息

关键词： smelting reduction chromite ore mechanism blast furnace

Effect of Zener-Hollomon parameter on deformation microstructure in Fe-3%Si alloy

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Acta Metallurgica Sinica(English Letters) 2011年第1期24卷 1-8页

作者： Fenghui AN Yuhui SHA fang ZHANG liang ZUO Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education) Northeastern UniversityShenyang I10819 China

Hot deformation of Fe=3%Si alloy within the temperature range of 1073-1473 K and strain rate range of 0.01-5 s-1 was carried out by compression test. Optical microscopy （OM）, electron backscattered diffraction （EBSD） and transmission electron microscopy （TEM） were used to characterize the deformation microstructure on various scales. Dynamic recovery is the dominant softening mechanism under all experimental conditions. A dynamic recovery region and partial dynamic recrystallization region can be distinguished according to Zener-Hollomon parameter （Z） based on OM observation. Furthermore, the quantitative description of subgrain size and boundary misorientation has been set up as a function of Zener-Hollomon Darameter.

关键词： Fe-3%Si Hot deformation Microstructure Zener-Hollomonparameter

Movement pattern of an ellipsoidal nanoparticle confined between solid surfaces: Theoretical model and molecular dynamics simulation

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Friction 2021年第5期9卷 1098-1109页

作者： Junqin SHI Xiangzheng ZHU Kun SUN liang fang State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049China State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi’an 710072China School of Mechanical and Electrical Engineering Xiamen University Tan Kah Kee CollegeZhangzhou 363105China

The movement pattern of ellipsoidal nanoparticles confined between copper surfaces was examined using a theoretical model and molecular dynamics ***,we developed a theoretical model of movement patterns for hard ellipsoidal ***,the simulation indicated that there are critical values for increasing the axial ratio,driving velocity of the contact surface,and lowering normal loads(i.e.,0.83,15 m/s,and 100 nN under the respective conditions),which in turn change the movement pattern of nanoparticles from sliding to *** on the comparison between the ratio of arm of force(e/h)and coefficient of friction(μ),the theoretical model was in good agreement with the simulations and accurately predicted the movement pattern of ellipsoidal *** sliding of the ellipsoidal nanoparticles led to severe surface ***,rolling separated the contact surfaces and thereby reduced friction and wear.

关键词： movement pattern friction and wear reduction ellipsoidal nanoparticle additive molecular dynamics simulation