bluuebunny/crossref_metadata_2025 huggingface dataset:
The Reaction Mechanism between Aluminum-Magnesia-Spinel Composite Material and RH Slag
Authors: Ma Guo Dong , Li Yong , Gao Yuan , Hong Shan Shan , Liu Ya Qin , Xia Wen Bin , Qian Zhi Ming , Huang Jing Heng
Published: April 2012

Unfired specimens were made with different aluninum content (0,2%,4%,6%,8%) respectively ,using high pure magnesia , magnesia-spinel and Aluninum as the main raw material. Unfired specimens were treated under the condition:110°C×24h drying,then 300°C×6h heating treatment.The properties and microstructure of the specimens were analyzed to investigate the reaction mechanism of these speciments and RH refinery slag.The result are shown that the addition of aluninum improves cold crushing strength of specimens,reaching to 63Mpa. The specimen with aluninum content of 8% shown the best slag resistance. The reaction mechanism between aluninum-magnesia-spinel complosite material and RH slag is different from magnesite-chrome brick. The major penetration element is Ca, and the Ca elment penetrated into the matrix reacts with corundum turning out a CA2 protective layer which can stop penetrating of slag.
Computing Method Investigation and Verification of Gas-Solid Combustion in Magnesium-Aluminum Based Propellant Ducted Rocket
Authors: Wang Wei , Li Jiang , Zhang Ke , Liu Yang
Published: April 2012

The combustion mechanism, which consisting of 22 species and 23 reaction equations, and three discrete models such as inertia, combusting, modification droplet, are employed for the investigation of gas-solid combustion in magnesium-aluminum based propellant ducted rocket based on thermal performance calculation. And path lines, temperature distribution, sediments are discussed after the computing method is validated by direct-connect experimentation and the flow field information, which obtained by numerical method and coincided with currently conclusions. The results indicated that the proposed method is reliable and practicable.
Preparation of In Situ Al3TiP/Al-Based Composite Coating
Authors: Niu Li Bin , Yuan Chun , Cao Du Meng
Published: April 2012

In the paper, titanium tri-aluminide (Al3Ti) particles reinforced aluminium (Al)-based composite coatings were fabricated by infiltration plus in-situ techniques at 891.3 °C. The obtained composite coatings are characterized by XRD, SEM and friction and wear testers. The experimental results show that the reaction between Ti wires and Al molten increases with extending time, Ti wires can totally transform into Al3Ti particles for 20 min, which present blocky and strip-like states, respectively. The wear rates of the composite coatings decrease with increasing time.
Properties Test and Analysis of Aloe Fiber Knitted Fabric
Authors: Feng Xiao Ting , Meng Jia Guang , Bai Juan
Published: April 2012

This article mainly introduced various properties of knitted fabric made of aloe fiber, including air permeability, moisture permeability, fastness, rigidity and flexibility, heat retention property, crease recovery, and made a comprehensive evaluation with fuzzy mathematics. Finally we obtained the best stitches applying to spring, summer, autumn and winter.
Numerical Simulation of GMAW Process Based on Level Set Method
Authors: Sui Li Jun , Xu Zhi Wu , Wang Li
Published: April 2012

A model based on level set function is proposed to predict gas shielded arc welding. The model describes not only the free surface tracking of molten drop and metal transfer in gas metal arc welding, but it simulates the phase change on substrate during heat transfer，which is based on porous media theory. The result of simulation shows that this model can describe the drop diameters, transfer frequency and the shape of solidification precisely.
Effect on Inclusion and Microstructure of Ultra-Low S and Low P Steels with Vacuum Treatment
Authors: Wang Hai Chuan , Liao Zhi You , Wang Shi Jun , Zhou Yun , Wu Bao Guo , Dong Yuan Chi
Published: April 2012

The simultaneous desulphurization and dephosphorization of molten steel with CaO-based slag containing BaO for vacuum treatment, and inclusion in steel and microstructure of steel are carried out separately. These results show that desulfurization rate exceed 92% and dephosphorization rate exceed 50% , final [S] content and [P] content in molten steel are less than 0.0024% and 0.020% respectively for all heats, and the lowest final [S] content and [P] content are 0.0012% and 0.010% respectively, they satisfy the demand of ultra-low S steels and low P steels; Comparing a grade 1.5 of inclusion level of the compared sample without vacuum treatment, inclusion level of these treated samples with vacuum is all less than grade 1.0 and that is less than grade 0.5 for 78% of treated samples; And micro-structure of the compared sample is ferrite + pearlite in steel base, but micro-structure of these treated samples is all needle-like ferrite + pearlite + netted ferrite in steel base and netted ferrite + pearlite in local area. This kind of fiber structure which comes from netted ferrite + needle-like ferrite and grade 0.5 of inclusion level can make steel possess better mechanical properties.
The Formation Process of Black Trivalent Chromium Conversion Coating on Zn Electrodeposit
Authors: Liu Hai Ping , Bi Si Fu , Teng Xiang Guo , Yu Yuan Chun
Published: April 2012

A black trivalent chromium conversion coating (CCC) was obtained on Zn deposit in chromium trichloride solution at 55 °C. The formation process of trivalent CCC on Zn deposit were thoroughly investigated by using X-ray fluorescence spectrometer and X-ray photoelectron spectroscopy in combination with atomic force microscopy surface analysis. The trivalent CCC on Zn deposit is consisted of Zn, Cr, O, Ni, Co, P and N elements, with visible micro-cracks on the film’s surface. The growth rate, the surface color and the morphology of this conversion coating vary with the dipping time.
Direct Observation of Hydroxyapatite Nanoparticles In Vivo
Authors: Zhou Wei , Zheng Jun
Published: April 2012

While nano-hydroxyapatite (nano-HAP) has been well known for series of amazing properties in chemical or physical, the controversy on the risks of its applications has also been existed. The worries of nano-HAP applications in preclinic and clinic indicate the blank researches of nano-HAP pharmacodynamics. It is important and necessary to trace and clarify the localizations of HAP nanoparticles in vivo. In the present paper, 18F is used as radiotracer for Positron Emission Tomography (PET) imaging of HAP nanoparticles. Through the transverse plane slices and three-dimensional reconstruction pictures, it is very clear to observe the localization of nano-HAP in vivo at real time. Most nano-HAP particles were noted in organs lump, liver, spleen, stomach and existed for period of time. Therefore, PET can be a new powerful technique for tracing nano-biomaterial and their pharmacodynamics researches.
Finite Element Analysis of Flexural Strength for Helical Gear of Automotive Transmission
Authors: Xie Fei , Wang Jian Hua , Wang Yun Cheng
Published: April 2012

On the basis of the analysis of special demand of helical gear of automotive transmission, gear precision modeling and finite element analysis of flexural strength were carried out in this paper. In UG three-dimensional modeling environment, helical gear model was generated and imported into ANSYS software through data exchange interface. Then meshed on the geometric model, discussed the tooth contact area and the detrimental loading position, and compared the influence on gear strength with different tooth root fillet radius. The paper provided certain methods to guide the gear parametric design, strength analysis and improving optimization design efficiency of transmission gear parts.
Improvement and Experimental Research on High-Pressure Gear Pump Based on Volumetric Efficiency
Authors: Bai Ping
Published: April 2012

Based on the basic structure of typical high-pressure gear pump, a new kind of high-pressure gear pump was designed and applied in water hydraulic transmission system. In this design, the floating plate of typical gear pump is ceramiclized to improve its wear-resisting property; the balance chamber was used to brace and lubricate the axle. Furthermore, the radial unbalanced force induced by the pressure difference of input and output is balanced by the structure of balance chamber. The dynamic characteristic of gear pump is improved and the axel wear is reduced. By using tip relief of tooth flank profile modification, the leakage rate of gear flank is effectively reduced, and the volume efficiency is improved.
Synthesis and Characterization of Hierarchical ZSM-48 Zeolite
Authors: Liu Xiao Ling , Wang Xu Jin , Wang Yan , Gong Yan Jun , Dou Tao
Published: April 2012

A series of hierarchical ZSM-48 zeolites was prepared by seed silanization. The structural and textural properties of the hierarchical ZSM-48 were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), N2 adsorption-desorption, 27Al and 29Si magic angle spinning nuclear magnetic resonance (MAS NMR), and Fourier transform infrared spectroscopy adsorbed by pyridine (Py-IR). It was found that the crystal size of ZSM-48 was significantly reduced by seed silanization. Due to the secondary porosity in the mesopore region generated in hierarchical ZSM-48, both the total surface area and the pore volume of the material have a considerable increase. The enhancement of the textural properties could be controlled by changing the amount of silanizaiton agent.
Numerical Simulation and Research of Far Infrared Sterilization Tunnel
Authors: Zhang Suo Huai , Wan Ming Wei
Published: April 2012

To establish a CFD model of far infrared tunnel, get numerical simulation dates of far infrared tunnel by using Fluent soft, compared with experimental dates. The results show that the numerical simulation can attend the temperature distribution inside the tunnel, Simulated and experimental temperature curve trend of the measured data.
Calculating Method about the Normal Clearance Magnitude of the Water Pump Shroud by the Boundary-Layers Theory
Authors: Li Li Hong , Li Xiao Li
Published: April 2012

The Normal clearance magnitude of the shroud in the engine cooling pump influences greatly on the performance of the pump. As yet there has been no any appropriate theory on it. The dimension of the clearance is now designed depending on plentiful experiments which may consume a great deal of manpower, materials and funds. The boundary-layers in shroud clearance of impeller can be considered as 3D symmetrical and rotational boundary layers which can be converted into 2D boundary by coordinate conversion. Then the Boundary-layers thickness in clearance can be calculated by the more mature method of computing 2D boundary-layers thickness. This method first breached conventional experiment way in determine the shroud clearance magnitude and supplied scientific theory to the engineering design. As a result, this method can save many of all kinds of the industrial resources, and give the more precise scientific reference to relative research about pump.
Research on the Special Load Deflection of the Annular Throttle Slice of Shock Absorber
Authors: Chen Yi Jie , Zheng Guan Hui , Ju Hai Jie , Guo Jian Juan , Han Xiao Ling
Published: April 2012

A research method of the deflection of throttle slice under the uniform distribution of variety load is presented. The analytical equation of slice deflection under the uniform distribution of variety load is deduced using the sheet mechanics according to the physical model of throttle slice, which is convenient for the theory analysis and engineering application. The correctness of equation is validated compared with finite element calculation results. The rules that different loads and the structure parameters and material characters of throttle slice influence on the deflection at any radius are studied. The analytical equation and conclusion offer reference to design throttle valve of shock absorber accurately.
Numerical Simulation Analysis of the Effect of Sheet Property on Forming Safety Margin of Drawing Panel
Authors: Guan Jing Jing , Wang Zhong Jin , Zhang Yi He
Published: April 2012

In order to research the relationship between drawing panels and sheet properties, some parts with typical deformation feature （shallow drawing, deep drawing and bulging-deep drawing）are chosen as analysis objects. Then, finite element method is used to establish the model that can describe the quantitative relation between blank performances and forming safety margin of drawing panel. With the model, the law that illustrates the influence of sheet properties on the deformation procedure of drawing panels is get, and the criterion for selection of panel material is provided for production.
Design a Two-Harmonics Transmission Mechanism with Roller Chain
Authors: Wu Yang Fang , Liu Hua , Shi Yong Gang
Published: April 2012

The binary row short-pitch transmission based precision roller chain highlights its radial flexibility and circumferential rigidity, it constructs a new type of harmonic transmission unit by replacing the tradition flexible wheel. Driven by a generator of mechanical harmonic wave the rollers of the binary row roller chain mesh with the teeth contour of the two inner gears which realizes reduction in small teeth difference and zero-tooth-difference synchronous output. The rotation components distribute uniformly on a plane. In theory, it is capable to eliminate dynamic imbalance factors. This paper detailed the principle of the harmonic drive meshing and gave out the design approach to control parameters of trough in the roller chain. Through the prototype testing, it confirmed the feasibility of this transmission mode.
Study of the Loading Arms of the Side-Crane Used for Container
Authors: Feng Xiao Mei , Zhan Jun Qing , Li Li Shun
Published: April 2012

As the important device, self-loading device plays a key role in the side-crane used for container. And as the key component of the self-loading device, loading arm’s strength analysis is very important. FEA is introduced into the arm’s strength and rigidity analysis, and under the precondition of satisfying allowable stress, minimum weight of the arm is taken as the design target. Ulteriorly, by obtaining optimal geometric parameters, the loading arm’s optimization design can be realized and its manufacture cost can be reduced.
Kinematics and Luffing Moment of Lemniscate Type Crane with Boom Driving
Authors: Li Ke Qin , Li Jun Ning
Published: April 2012

The lemniscate type crane is fabricated by Figee B.V. of the Netherlands. There are great differences in outward appearance, geometric shape, luffing performance between lemniscate type crane and ordinary double-link type crane. Lemniscate type crane has some advantages, i.e. lower centre of weight, practical and reasonable structure, strongly anti-wind and easy operation. Based on inverse design and theory of mechanism, instant centers of velocity, luffing locus and moment of lemniscate type crane is studied and solved. The equations of kinematics and luffing moment are obtained.
Profile Processing of Scroll Compressor and its Error Analysis
Authors: Hu Rong Hua , Liu Qiang Fei , Song Hong Gun
Published: April 2012

In order to process the involute curve profile of scroll compressor，the method of using Archimedes spiral to approximate the involute curve in the polar coordinates is used.The error of approximation caused by different interval distances of interpolation points is simulated by Matlab.The machining experiment of orbit scroll using the appromation method of equal-radial- interval is carried out on CNC machine tool,and the interpolation error of actual machining is . The effectiveness and practicality of the method were tested and varified.
Research on Multi-Point Spraying of Central Air-Conditioning System
Authors: Yan Su Qian , Wang Xi Wen
Published: April 2012

Multi-point spraying air-conditioning room is widely used in some textile mills due to the advantage of no spray pipe and high power water pump. This article take the textile air-conditioning rooms as an example, comparing with the design of supply air system and result of experiment tests, the characteristics of multi-point spraying of air-conditioning system in supply air and heat and moisture exchange efficiency during actual operation are obtained. Besides, comparing with the wind pressure chart of the design of supply air system and result of experiment tests, it comes to a conclusion that Multi-point spraying air-conditioning room should be improved according to their own situation in actual operation. It also proposes the feasibility of wind pressure chart for regulate of supply air system.
Calculation of Initial Ejection Force in Basin Type Insulator Epoxy Injection Mould
Authors: Zhang Xin Rong , Shi Qi Hao , Wu Wen
Published: April 2012

It is of great significance for the design of ejection mechanism and the control system of automatic ejection machine that the initial ejection force of injection mould can be calculated. According to the production status of basin type insulator epoxy injection mould, the influencing factors on the ejection force were analyzed. The calculating formulae of initial ejection force for cavity with different structures were derived and verified using methods of mechanics analysis, arithmetic average and the thoughts of molding mechanical performance submits Hook’s law. The verification result shows that the initial ejection force can be better estimated and used as a reference to design.
The Forward Solution of Kinematics About 5-DOF Dispensing Manipulator
Authors: Ren Gong Chang , Wang Yong Fei , Ye Qing , Chen Bo
Published: April 2012

The dispensing manipulator is one of the focus-researching projects at present,according to 5-DOF dispensing robot,firstly we completed designing the structure diagram of manipulator,and then used the mathematica calculation to finish the forward solution of kinematics about 5-DOF dispensing maniputor,which is derived the overall transformation matrix of the maniputor.finally we verified the correctness of the overall transformation matrix through the actual example.It is proved that the method have provided a reference for the kinematics equations of general maniputor.
The Design and Simulation of Space Surface Based on Reverse Engineering
Authors: Gao Dong Qiang , Lin Huan , Shi Zhi Fang , Yi Jiang Miao
Published: April 2012

In this paper, according to the principle of reverse engineering, first, we got experimental data by three coordinate measuring machines. Then carried on the data processing and surface reconstruction so as to complete the space surface mold design, final the numerical control simulation is performed in the software.
Analysis of Electromagnetic Compatibility about Air-Power-Off of Aircraft Power System
Authors: Sun Guo Qiang , Guo Gang , Yang Yong Bo , Yang Dong Ping , Zhang Jian Feng
Published: April 2012

At present, main AC power systems of advanced fighters all apply digital controllers with microprocessors. The signal input and output circuits are vulnerable to the effects of electromagnetic interference, which may cause air-power-off fault. The paper analyzes the electromagnetic environment on the aircraft, discusses the airborne electromagnetic compatibility by comparing domestic and international contents and limitations of the electromagnetic standard. Furthermore, it proposes measures to resolve the electromagnetic compatibility
Study on Pipeline Transportation Experiment of Paste Filling Material
Authors: Liu Jin Xiao , Guo Wei Jia , Yin Zeng De
Published: April 2012

The change law of basic paste material performance in the pipeline must be studied to verify long distance transportation in coal mine after the ratio of paste material is completed. This paper introduced simulation system which was developed by us and the pipeline transportation experiment was done. The change law of paste material parameters was studied including collapsed slump, segregation degree and density with pipeline experiment. And the contents of this paper could provide theoretical guidance for field paste filling.
Study on Fatigue Crack Behavior in Welded Structure of DSS 2205
Authors: Wang Zhi Xiang , Wang Zheng Lun , Zhang Xin
Published: April 2012

The fatigue crack growth behavior of weld metal (WM), heat affected zone (HAZ) and base metal(BM) of Duplex Stainless Steel (DSS) 2205 standard sample was tested in different stress ratios at HF fatigue testing machine. ANSYS analysis software was used to simulate the fatigue crack growth rate of the steel under different stress ratio. Regression equations and da / dK-ΔK curves of experiment and simulation are compared and analyzed. The results show that the fatigue crack growth rate of WM is slowest and the ability to resist fatigue crack growth is highest among the three parts, the lowest is BM. Secondly, the sensitivity of the rate caused by the stress change of WM is the highest, and the lowest is BM. The simulation of fatigue crack growth rate of DSS 2205 is completely correct and feasible by the experiment.
Multiscale Modelling of Morphological Evolution of Rough Surface during Superficial, Volume and Evaporation-Condensation Diffusions
Authors: Bigerelle M. , Favergeon Jérôme , Mathia T. , Iost Alain
Published: April 2012

Fractal functions are used to model a metallic interface. An analytical model described by three partial differential equations is built to model time evolution of the surface during heating including three different mechanisms of diffusion: superficial diffusion (SD), volume diffusion (VD) and diffusion by evaporation-condensation (DEC). Initial topographies are modeled by Stochastic Weierstraβ functions because of their ability to reproduce experimental roughness profiles. Applied to an aluminum alloy at 550°C, a high number of roughness parameters and their variance are calculated. A classification method shows that the best geometrical approach that discriminates heat effect is the fractal dimension. The most popular parameter, Ra, badly discriminates processes (classification number = 58). The four order spectral moments of the roughness profile are correlated with the evolution of profile. It is shown theoretically that the superficial diffusion depends directly to the fourth spectral moment of the roughness profile.
High Temperature Diffusion Processes at the Metal/Slag Interface
Authors: Bogusz Agnieszka , Masset Patrick J.
Published: April 2012

The interface metal/molten oxide is of interest for several high temperature processes (metallurgy, gasification). The exchange reactions occurring at the interface between the metal and the molten slag are complex and up to date not well understood. More generally, this is of importance for the understanding of the exchange reaction kinetics between one metallic compound (solid or liquid) and an ionic one (slag). This work proposes a theoretical approach which takes into account the effect of speciation in the slag on the diffusion process of the species in the two phases and the redox reaction occurring within the vicinity of the interface. The systems investigated consist of Fe and CaO-SiO2 without convection. The concentration profiles of silicon and iron oxide in both parts were calculated. The effect of impurities present in metal phase such as sulphur in the molten slag was investigated. This provides a basis of comprehensive approach for the purification of metal and a better understanding of processes at metal/oxide interface.
Structural Re-Organization Kinetics of Nanocrystalline Pt Films during In Situ Annealing
Authors: Gruber Wolfgang , Chakravarty Sujoy , Baehtz Carsten , Schmidt Harald
Published: April 2012

In this work we investigated the structural re-organization of thin nanocrystalline Pt films in the temperature range between 250 °C and 400 °C by in-situ XRD, GIXRD and XRR synchrotron experiments. A re-orientation of (111) atomic planes and a relaxation of residual stress occurs. After heating up, Bragg peak fringes can be observed in the diffractograms. They are a direct proof that the Pt films are built of (111) columnar grains which essentially reach the whole film thickness of about 40 nm. During isothermal annealing a relaxation of the dispersion parameter of the atomic planes takes place which is associated with an activation energy of (0.4 ± 0.1) eV.
Helium Behaviour in Fe-Base Materials: Thermal Desorption and Nuclear Reaction Analyses
Authors: Lefaix-Jeuland Hélène , Miro Sandrine , Legendre Fabrice
Published: April 2012

Polycrystalline Fe 99.95 and 99.5 samples were implanted with helium at 8 keV and 3 MeV. Thermal Desorption Spectroscopy (TDS) and Nuclear Reaction Analysis (NRA) provided a complementary set of techniques to characterize helium-materials interactions within two different implantation depths, respectively close to the surface and in the bulk. Using TDS, it was possible to get information about the nature and the states of the structures where helium was trapped in radiation damaged Fe specimens. Activation energies for every trapping site (mono-vacancies, clusters) have been determined from conventional reaction model. The effect of interstitial carbon was also discussed, and compared with previous ab-initio studies. Moreover, the helium bulk diffusion constants in radiation damaged structures could be derived from non destructive 3He depth profiling. Preliminary observations highlighted that a few part of He remained trapped while helium bubbles migrated in the bulk.
Controlling the Molecular Interactions to Improve the Diffusion Barrier of Biosourced Polymers to Organic Solutes
Authors: Fang Xiao Yi , Vitrac Olivier , Domenek Sandra , Ducruet Violette
Published: April 2012

The presented original work examines how sorption and diffusion can be combined at molecular scale in nanocomposite materials to improve the resistance to diffusion of biosourced or biodegradable polymers. The concept is applied to apolar penetrants and discussed on polycaprolactone (PCL) containing organomodified montmorillionites acting as nanoadsorbents.
Determination of Diffusion Coefficients Using Thermogravimetric Measurements during High Temperature Oxidation
Authors: Berthod Patrice , Aranda Lionel
Published: April 2012

Thermogravimetry measurements associated to concentration profiles allow determining a diffusion coefficient at high temperature of the most oxidable one among the metallic elements belonging to the chemical composition of an alloy. In this work the employed method is described and applied to chromia-forming alloys essentially based on nickel but also to selected cobalt-based and iron-based alloys. More precisely DCr values were estimated for chromium diffusing through the carbide-free zones developed during high temperature oxidation. The effects of the base element, of the chromium carbides density and of the dendritic orientations on the chromium diffusion were evidenced.
Physics on the Top of the Tip: Atomic Transport and Reaction in Nano-Structured Materials
Authors: Schmitz Guido , Baither Dietmar , Balogh Zoltán , Chellali Mohammed Reda , Greiwe Gerd Hendrik , Kasprzak Michael , Oberdorfer Christian , Schlesiger Ralf , Stender Patrick
Published: April 2012

Nanoscale systems show a wide variety of physical properties that cannot be observed in the bulk. Using atom probe tomography, it is possible to study nanostructured materials with almost atomic resolution in all three dimensions. In this article, we will present a short review of the latest atom-probe measurements carried out at University of Münster with particular focus on diffusion and segregation measurements in triple junctions and interface analysis.
Optimisation of Nickel Aluminising by CVD
Authors: Masset Patrick J. , Bogusz Agnieszka , Sieniawski Jan , Wierzba Bartek , Tkacz-Śmiech Katarzyna
Published: April 2012

Results Concerning Nickel Aluminisation with Application of Chemical Vapour Deposition Method Are Presented. Two-Step Processing under Investigation Consists of Al Chloride Formation in the Primary Vessel and Al Deposition in the Secondary One. the Initial Gas Stream Is Composed of Hcl Dissolved in H2 at Various Ratios. it Was Shown that the Choice of the [HCl]/[H2] Ratio and the Determination of the Optimum Temperature to Produce Most Preferential β-Nial Phase May Be Done with the Use of Thermodynamic Calculations. the Results Obtained with Application of Factsage Program Confirm Essential Influence of both Initial [HCl]/[H2] Ratio (in the Range between 0,05 and 100) and the Temperature in the Second Vessel (1123 K – 1323 K) on Aluminium Chloride Partial Pressures and Hence Aluminium Content in its Gaseous Donors and at the Substrate Surface (boundary Condition for Interdiffusion in Ni-Al System). it Was Confirmed that β-Nial Growth Is Favoured at Low [HCl]/[H2] Ratios and High Temperatures for which Alcl and AlCl2 Partial Pressures Increase with Respect to that of AlCl3. the Thermodynamic Predictions Remain in Agreement with CVD Experiments. the Presented Thermodynamic Data May Be Used as a Source of Essential Information for Designing Further Experiments in this Field as Well as for Modelling of Solid-State Diffusion in Ni-Al System.
Modelling of the Growth of Fe2B Layers in AISI 1018 Steel
Authors: Abdellah Z. Nait , Keddam Mourad , Elias A.
Published: April 2012

In this work, a simulation of the growth kinetics of layers on AISI 1018 steel was done by means of a kinetic model. This model considers a solid diffusion of boron into a semi-infinite medium where the boron solubility in the Fe phase depends on the process temperature. An expression of the parabolic growth constant was then obtained through an application of the mass balance equation at the (/substrate) interface. The present model was validated by the experimental data available in the reference work (I. Campos-Silva et al: Kovove Mater. Vol.47 (2009), p.1-9). A good concordance was observed between the experimental parabolic growth constants and the predicted ones by the model for an upper limit of boron in the phase equal to 8.91 wt.% ( as a fitting parameter of the model). In addition, the generated weight gain was estimated at the surface of the borided AISI 1018 steel as a function of the upper limit of boron in the phase and the temperature.
Reactive Diffusion of Thin Si Deposits into Ni (111)
Authors: Lalmi B. , Girardeaux C. , Portavoce Alain , Aufray Bernard , Bernardini Jean
Published: April 2012

Low energy electron diffraction (LEED), Auger electron spectroscopy (AES) and scanning tunnelling microscopy (STM) were used to study the reactive diffusion of one monolayer of silicon deposited at room temperature onto a Ni (111) substrate. We have done isochronal and isothermal kinetics by AES, and we observed in both cases a kinetics blockage on a plateau corresponding to around one third of a silicon monolayer. STM images and LEED patterns both recorded at room temperature just after annealing, reveal formation of an ordered hexagonal superstructure corresponding probably to a two-dimensional surface silicide.
Nanometric-Size Effect upon Diffusion and Reaction in Semiconductors: Experimental and Theoretical Investigations
Authors: Portavoce Alain , Girardeaux Christophe , Tréglia Guy , Bernardini Jean , Mangelinck Dominique , Chow Lee
Published: April 2012

The use of nanometric size materials as embedded clusters, nanometric films, nanocrystalline layers and nanostructures is steadily increasing in industrial processes aiming to produce materials and devices. This is especially true in today Si-based microelectronics with transistors made of a multitude of different thin film materials (B-, As-, and P-doped Si, NiSi (Pt), poly-Si, W, TiOx, LaO, SiO2, Al, HfO2), and exhibiting a characteristic lateral size of 32-22 nm. Size reduction leads to an increasing role of surfaces and interfaces, as well as stress and nanoscale effects upon important phenomena driving fabrication processes, such as atomic diffusion, phase nucleation, phase growth, and coarsening. Consequently, nanotechnology related to Material Science requires an investigation at the nanometric (or atomic) scale of elementary physical phenomena that are well-known at the microscopic scale. This paper is focused on nanosize effects upon diffusion in Si and Si reactive diffusion. We present recent results showing that the kinetic of lattice diffusion is enhanced in semiconductor nanometric (nano) grains, while grain boundary (GB) diffusion is not changed in nanoGBs. It is also shown that diffusion in triple-junction (TJ) is several orders of magnitude faster than GB diffusion, and that its effect cannot be neglected in nanocrystalline (nc) layers made of 40 nm-wide grains. Experimental results concerning Si sub-nanometric film reaction on Ni (111) substrate are also presented and compared to theoretical results giving new prospects concerning nanosize effects on reactive diffusion at the atomic scale.
Diffusion Behaviour of the Grain-Growth Inhibitor Vc in Hardmetals
Authors: Brieseck M. , Hünsche I. , Caspers B. , Gille G. , Bohn M. , Lengauer Walter
Published: April 2012

Diffusion couples of the type WC-Co/VC-Co were employed to observe the diffusion behaviour of the grain-growth inhibitor (GGI) VC within nanoand ultrafine-grained WC-10wt.% Co samples. Since diffusion of the GGI during heating occurs already in the solid-state regime, interrupted sintering experiments were performed up to the liquid phase formation temperatures. By the use of light-optical and scanning electron microscopy the impact of GGI concentration on the microstructure as a function of depth from the interface was investigated. Electron Probe Microanalysis (EPMA) was used in order to quantify the amount of vanadium diffused into WC-Co as a function of distance. In first approximation, an activation energy of 3.45 eV (332,6 kJ/mol) for vanadium transport was determined.
Atomic-Scale Materials Processing under Strong Gravitational Field
Authors: Mashimo Tsutomo
Published: April 2012

A strong gravitational field causes the changes in composition and structure through sedimentation or displacement of atoms in multi-component condensed matter. We have developed a high-temperature ultracentrifuge to generate a strong acceleration field of even over 1 million (1x106) G, and, for the first time succeeded in realizing the sedimentation of the constitutive solute atoms and aeven isotope atoms in solids or liquids. The changes in composition and crystalline state of various alloys, polymers, and other substances have been investigated. Recently, we started the experiments on compounds and semiconductors with the aims of new materials synthesis and semiconductor control. The chemical reaction, crystal structure change have been found for metallic compound (Bi3Pb7), or covalent compounds (Y1Ba2Cu3O7-x, TiO2, etc.). The impurity control was also examined in semiconductor. In this article, the recent progress and the future prospects for materials processing are described.
Investigation on Mechanism of Faceted Cellular Array Growth in International Space Station
Authors: Inatomi Y. , Yoshizaki I. , Sakata K. , Shimaoka T. , Sone T. , Tomobe T. , Adachi S. , Yoda S. , Yoshimura Y.
Published: April 2012

An in situ observation experiment of faceted cellular growth was carried out using transparent organic alloy, salol - t-butyl alcohol, in microgravity conditions on the International Space Station. The temperature and solute concentration fields in the vicinity of the solid-liquid and the growth rate were simultaneously measured by microscopic interferometers.
Bulk Growth of InGaSb Alloy Semiconductor under Terrestrial Conditions: A Preliminary Study for Microgravity Experiments at ISS
Authors: Arivanandhan M. , Rajesh G. , Tanaka A. , Ozawa T. , Okano Yasunori , Inatomi Y. , Hayakawa Yasuhiro
Published: April 2012

As a preliminary experiment for the growth of InGaSb alloy crystals under microgravity at International Space Station (ISS), bulk crystal was grown under terrestrial condition using the same gradient heating furnace (GHF). Czochralski grown GaSb <111>B single crystal was used as a seed and feed crystals for the growth of InGaSb bulk crystals. During the growth, heat pulses were intentionally introduced periodically to create the growth striations. From the striations, the growth rate of the grown crystal was estimated. The results show that the growth rate was gradually increased from the beginning of the growth and became stable. On the other hand the In composition of the grown crystal decreased along the growth direction. From the In composition, the temperature gradient in the solution was estimated and it was almost the same of that fixed during the growth.
Controlling the Diffusive Field to Grow a Higher Quality Protein Crystal in Microgravity
Authors: Tanaka Hiroaki , Inaka Koji , Furubayashi Naoki , Yamanaka Mari , Takahashi Sachiko , Sano Satoshi , Sato Masaru , Shirakawa Masateru , Yoshimura Yoshinori
Published: April 2012

Growing high quality crystals is a bottleneck in the multi-stepped process of three-dimensional structural analyses of protein. It is known that a microgravity environment may maintain ideal depletion zones of protein and impurity around a growing crystal and the filtering effect of these depletion zones may contribute to obtaining high-resolution X-ray diffracting crystals with superior internal order. The effects of these depletion zones around growing crystals are thought to be the main mechanisms for the improvement of crystal quality in microgravity. A competition between the diffusion of protein molecules in the solution (indexed by the diffusion coefficient, D) and the adsorption of those into the growing crystal (indexed by the kinetic coeffcient, β) decides the extent of depletion zones. Lower D values and higher β values indicate that these effects are more obvious in numerical analyses. Therefore we use the D/β value as an index for these effects. The most effective method of lowering the D/β value is using viscous precipitant reagents, such as a high molecular weight polyethylene glycol (PEG) to decrease the D value and using highly homogenous protein samples to increase the β value. In this report, we briefly introduce simple yet practical methods of estimating D and β values followed by a numerical analysis to understand the filtration effects, and the results of crystallization experiments in microgravity when controlling the diffusive field around the growing crystals using the D/β value as an index.
26Al Tracer Diffusion in Nominally Undoped Single Crystalline α-Al2O3
Authors: Fielitz P. , Borchardt Günter , Ganschow S. , Bertram R.
Published: April 2012

Simultaneous 18O and 26Al tracer diffusion experiments were performed in nominally undoped single crystalline α-Al2O3. The results clearly show that the bulk diffusivity of aluminium is much higher than the bulk diffusivity of oxygen in nominally undoped alumina. Comparing the 26Al tracer diffusivities of Ti doped (300-400 wt. ppm Ti) and nominally undoped single crystalline α-Al2O3 one finds that the aluminium bulk diffusivity is insensitive to the Ti doping.
Numerical Aspects of Electrodiffusion Problem Based on Nernst-Planck and Poisson Equations
Authors: Fausek Janusz , Szyszkiewicz Krzysztof , Filipek Robert
Published: April 2012

Motivation for this work comes from the application of the inverse method to electrochemical systems. The basic process operating in these systems is electrodiffusion, which can be described by the full form of the Nernst-Planck and Poisson equations. No simplification like electroneutrality assumption is used. Numerical procedure based on the method of lines (MLs) for time dependent electrodiffusion transport is presented with any number of ionic species. The resulting system of ODEs is effectively solved by employing different integrators (Radau IIA, Rosenbrock, SEULEX). Selected electrochemical systems (liquid junction, bi-ionic case, ion selective electrodes (ISE)) are treated. Performance of the integrators is compared.
The Properties of Steel Slag Bricks Prepared by both Alkali Activation and Accelerated Carbonation
Authors: Zhang Wen Sheng , Shi Di , Shao Zhong Jun , Ye Jia Yuan , Wang Yuan
Published: April 2012

The physical and chemical evolutions, including strength, porosity, chemical and mineral compositions, of properties of steel slag bricks prepared by both alkali activation and accelerated carbonation were investigated. The results show that alkali activation provides the initial properties, while accelerated carbonation plays a dominant role in such final performances as strength, porosity, chemical and mineral compositions of steel slag bricks. The steel slag bricks with a compressive strength of 33.8MPa, carbonation degree of 8.92% and porosity of 23.25% were successfully prepared after accelerated carbonation curing (T=50°C, RH=60%, P=0.25MPa, ρCO2=80% by volume) for 120min.
The Study on the Impact of Recycled Fine Aggregate and Powder on the Mechanics and Thermal Performance of Recycled Concrete Hollow Blocks
Authors: Zhou Wei , Lu Ling Huan , Li Zhen
Published: April 2012

The impact of recycled fine aggregate and powder on the mechanics and thermal performance of recycled concrete hollow blocks was discussed in this paper. The results showed that 30% recycled fine aggregate and powder have slight affect on the strength of recycled concrete hollow blocks. But the strength reduced significantly when the replacement is above 50%. The impact of recycled fine aggregate and powder on the performance of concrete hollow blocks with high strength grade is notable . The heat transfer coefficient of recycled concrete hollow blocks with 30% recycled fine aggregate and powder was equivalently to ordinary concrete hollow blocks.
Application of Limestone Manufactured Sand as Fine Aggregate in Asphalt Concrete
Authors: Wu Shao Peng , Cui Pei Qiang , Zhang Deng Feng
Published: April 2012

The property of aggregate has a significant effect on the performance of asphalt mixture because of its high proportion. Asphalt mixture prepared by some kind of aggregate cause the inadequate compaction problem, which results in moisture damage due to its large air void. Limestone manufactured sand is considered as one of the useful solution to overcome the compaction problem. In this paper, fine aggregate is substituted by different proportion of limestone manufactured sand (LMS). The effect of replacement ratio on volume properties and pavement performance is studied. The results show that the limestone manufactured sand can improve the pavement performance and is benefit to the compaction of andesite asphalt mixture. Furthermore, this research also provided some valuable parameters for guiding the pavement construction in the future.
Moisture Sensitivity of Bituminous Mixtures with Compound Fly Ash Modifier
Authors: Xie Jun , Cai Jun , Wu Shao Peng , Pang Ling
Published: April 2012

Bitumen pavement suffers from moisture damage mainly due to loss of durability and stability in a short span of service life. Filler is known to be capable of increasing the stiffness of bitumen binder, contributing to improvement of moisture sensitivity of bitumen mixture. In this paper a new type of filler named 'Compound Fly Ash Modifier' (CFAM) was introduced in order to enhance the bond strength between acidic aggregate with bitumen. The primary object is to determine the effect of CFAM on the moisture sensitivity of bitumen mixtures prepared by gneiss and granite respectively, which are termed acidic aggregate. Modified Lottman test and fatigue test were conducted. The results show that CFAM improves the resistance of mixes to moisture damage in the increase in indirect tensile strength and the extension of fatigue life. Finally the mechanism of modified effects for CFAM is discussed.
Research on Pavement Performance of Steel Slag Conductive Asphalt Concrete for Deicing and Snow Melting
Authors: Chen Feng , Chen Mei Zhu , Wu Shao Peng , Zhang Ji Zhe
Published: April 2012

The key point of preparing conductive asphalt concrete for deicing and snow melting is pavement performance must satisfy the requirements before it can melt snow successfully. This study prefers to prepare electrically conductive asphalt concrete choosing steel slag as the whole aggregates and conductive minerals, while mixed with graphite and carbon fiber. Moisture susceptibility has been evaluated through water-saturated Marshall Stability test and indirect tensile splitting strength test. High temperature performance and fatigue performance were analyzed through dynamic creep test and indirect tensile fatigue test. Results indicate: High temperature performance of steel slag conductive asphalt concrete is better than ordinary basalt asphalt concrete, while its moisture susceptibility and fatigue performance is not good enough and need to be improved.
Research on the Fatigue Properties of Organo-Montmorillonite Modified Bitumen Mortar
Authors: Liu Xing , Wu Shao Peng , Pang Ling , Guo Pei Da
Published: April 2012

This study investigated the fatigue properties of organo-montmorillonite modified bitumen mortar. Organo-modified montmorillonite（OMMT）with a content of 5 wt% was used to modified one base bitumen mortar which consist of filler and bitumen at a weight ratio of 0.8:1. The fatigue properties of these bitumen mortars have been determined using a dynamic shear rheometer（DSR）through time sweep test. Result indicated that, due to the addition of the OMMT, the fatigue properties of modified bitumen mortar was superior to those of pristine mortar. Therefore, the OMMT would be an alternative to modifiers used in the bitumen to improve the lifetime of asphalt pavement. Meanwhile, some fatigue equations were estabilished.
Influence of Mechanically-Treatment on Physical-Chemical Properties of Circulation Fluidized Bed Combustion Fly Ash
Authors: Chen De Yu , Yan Yun , Liu Yuan Zheng , Huang Meng
Published: April 2012

The comprehensive performance, such as water demand, hydration heat, expansion, and self-hardening of circulation fluidized bed combustion (CFBC) fly ash ground by the laboratory mill were studied in this paper. Results show that the percentage of fine particles and fluidity of CFBC fly ash increased with grinding time. However, the water demand at normal consistency of the CFBC ash decreased with grinding time. The hydration exothermic rate of the paste has been accelerated and the time of reaching the volume stability has been shortened. Meanwhile, the compressive strength of the paste and the content of ettringite in the matrix increased with the curing time in the early age, but reversed later.
Study on Preparation and UV Ageing Resistance Effect of LDHs Modified Asphalt
Authors: Wang Jin Shan , Wu Shao Peng , Han Jun , Liu Xing
Published: April 2012

Abstract: The anti-aging asphalt modified by Supramolecular Ultra Violate(UV) Light Resistant material which is Layer double hydroxides (LDHs)was prepared in this paper, by using mechanical mixing, LDHs by various mass ratio were added into different typical asphalts. Taking the influence of the factors into account, including mechanical dispersing technologies, reaction conditions(temperature and time), content of the LDHs, the mutual consistent of LDHs among asphalt and storage stability was studied by segregation process and microstructure analysis (X-ray diffraction、Scanning Electron Microscope). Then after thin-film-oven-test (TFOT) and the artificial accelerated UV aging tests to simulate long-term UV aging, basic properties tests were conducted in this paper. The results showed that the UV anti-aging properties of the asphalt were greatly improved. Key words: LDHs; preparation manners; UV anti-aging