bluuebunny/crossref_metadata_2025 huggingface dataset:
Research and Design on a New Roll of Material Conveying Composite Regulating Machine System
Authors: Liu Jun Xu
Published: April 2012

This paper studies the old offset machine mathematical model, corrects the shortcomings of its mathematical model and presents a more effective, more reasonable mathematical models. Then the conceptual designs, system design, structure design of the model are carried out. After nearly 2 years operating, the deviation adjusting mechanism has been proved to possess a good practicability and adjusting deviation.
A New Method for Optimal Configuration of FMS Based on Machining Features
Authors: Cai Xiu Nv , Zhang Ying Jie
Published: April 2012

This paper investigates the reconfiguration of manufacturing systems like flexible manufacturing systems (FMS) based on machining features. The focus of the research is to find out the optimal configuration of flexible manufacturing systems by machining features in terms of the manufacturing requirement of parts, to reduce the total construction cost or the whole machining time. The objective is to get the optimal configuration of FMS for a specific part family from the available machines of a manufacturing cooperation, in this paper, a new method for the configuration of FMS based on machining features is proposed. The prototype has been implemented for a machine manufacturing cooperation in China, where the configuration of FMS is used to machine several parts and components of trucks.
Research of Alloy Orb on Wavelet
Authors: Zhang Shu , Meng Lei
Published: April 2012

via completely after heat-treatment, [111] orientation of single crystal alloy structure is still cubic  phase at way coherency are ordered in matrix g panel and the direction rules arrangement; In high temperature and tensile stress creep period, with stress axes ordered  has formed certain Angle raft shape organization, creep later in nearly fracture zone, raft shape  ordered caring and distortion in happen, with strain increases, coarsening and distorted aggravating, until the present wavy shape; During the creep [111] orientation of single crystal alloys deformation characteristics is a wrong in  matrix channel to sports and shear raft shape  phase, due to form larger, more variable dislocation cut ordered after raft shape , occurred in dislocation bunch of sets and its formation and crystal structure; Among them, the matrix channel to inherit the maximum shear dislocation slip is made of alloy with larger strain rate main reason.
The Important Influencing Factors of Coefficient of Friction Testing on Metallic Sheet and Strip
Authors: Xue Huan , Li Rong Feng , Zhu Hong Chuan , Peng Wen Jie
Published: April 2012

The importance of the coefficient of friction test in sheet metal forming field is introduced. Metallic sheet and strip testing method for coefficient of friction is described, the experimental principle of the testing method is introduced. Three important factors, which will obviously effects the test results, including testing mould, specimen width and surface lubrication conditions have been carefully studied. The comparatively stable testing technologies have been developed to guide the test.
Investigation on the Alkali Resistance Property of Theoretical Composition Magnesia Alumina Spinel Bricks
Authors: Hong Shan Shan , Li Yong , Liu Ya Qin , Gao Yuan , Ma Guo Dong , Li Jin Bao , Qian Zhi Ming , Huang Jing Heng
Published: April 2012

Using alumina-rich MgAl2O4 spinel AR78 and 97 fused magnesite as raw materials, brine as the binder, magnesia alumina spinel bricks close to theoretical composition have been prepared. The phase composition and microstructure of the specimens were analyzed and characterized. The alkali resistance property of specimens was researched using static crucible method. The erosion mechanism of alkali vapor to specimens was studied by XRD, SEM and EDS. The results show that: (1) The alkali resistance property of MgAl2O4 spinel bricks were improved obviously when the addition of magnesite is more than 7%. (2) The alkali resistance property of MgAl2O4 spinel bricks is the best when the addition of magnesite is 10.3%.
Preparation by Spark Plasma Sintering and Investigation of Inert Anode for Aluminum Electrolysis
Authors: Zhang Guo Dong , He Zhi Min , Zhang Jian Qiang , Zhang Fu Ju
Published: April 2012

Spark plasma sintering was used to prepare Fe-Ni (Cu-41.32wt.% Cr) alloy in order to enhance the properties as inert anode for aluminum electrolysis. The effect of different sintering processes on the microstructures and properties of Fe-Ni alloy were studied by OM, SEM and EDS. The results show that the sintering process of milled powders can be divided into three stages: particles bonding, sintering neck growing, closed pole gap becoming spherical and narrowing. The SPS process of milled powders has some advantages of reacting at lower temperatures, completing faster and being densified easier than ordinary sintering. The density of Fe-Ni sample is improved and porosity is decreased as the sintering temperature is increased and holding time is extended. 1273K and 5min are the best parameters.
Effect of Matching Performance on J-Integral of Inhomogeneous Welded Joints
Authors: He Bo , Zhang Hong Cai
Published: April 2012

In this paper, J-integral of 3-zone inhomogeneous welded joint is calculated by use of the finite element method, and the impacts of yield strength matching factor and elastic modulus matching factor on J-integral are studied as well. The analysis results show that the yield strength matching factor affects J-integral value greatly, that is, low matching of inhomogeneous welded joint of same steel can help to improve the ductility of the welded joint and the influence of yield strength matching factor on J-integral is much greater than that of elastic modulus matching factor, so it plays a very important role in the engineering design.
Temper-Resistance of Cr-W-Mo-V High Carbon Medium Alloy Steel and its Hardness Forecast
Authors: Ma Yong Qing , Dai Yu Mei , Liang Yu Fen , Zhang Xiao Jing
Published: April 2012

The temper-resistance temperature of Cr-W-Mo-V high carbon medium alloy steels is in a range at 200°C-300°C. Along with increasing C and alloy contents in particular Cr content of the steels, the temper-resistance is boost up gradually and maximal hardness arrives to 63-64HRC at temperature 200°C-250°C. When budget for quenching matrix composition and undissolved carbides, the actual quenching temperature TH is corresponding to the calculational temperature TC by phase-equilibrium thermodynamics as TH=TC + (1000°C－TC)/6.5, and roughly, the calculational temperature is less 20°C than actual temperature when quenching at 800°C-890°C. The carbides precipitation during tempering is agreement with phase equilibrium thermodynamic calculation incompletely, thereinto (Fe,Cr)3C carbide precipitation is leading at 200°C-250°C.The higher hardness at temper-resistance temperature is corresponding to tempering temperature of remnant austenitic decomposing acutely.The tempering hardness can be estimated on the basis of quenching hardness calculation. The quenching hardness value can be obtained from HC=α（1+β）/(0.00915α+0.00527), in which α is the square root of carbon content in the matrix and β is correction coefficient of solid solution strengthening.
Technique of Extrusion Forming and Design of Die for Guiding Cylinder
Authors: Xin Xuan Rong , He Cheng Song , Liu Xin Cheng , Liang Kun
Published: April 2012

The feasibility of extrusion forming of guiding cylinder was discussed. Based on the analysis of several technological programs, the optimal plan selected, the technological process was determined and the extrusion die was designed. With the application of cold extrusion technology, the precision and surface quality of the product is increased, the intensity and toughness is improved, the amount of fining operation is decreased, quantities of materials are economized, the production efficiency is raised and the structure property of the component is got better.
On Multi-Ring-Degree Interactive Display of Products Based on Virtools Platform
Authors: Guo Fang , Sheng Hong Fei , Pang Ai Min
Published: April 2012

Taking the new eco-car as an example, the article firstly introduced the Virtools platform,which is used for the realization of product display. Then it designed the realization process of product display and further studied the detailed realization process of product interactive display. Finally, it discussed the characteristics of the virtual display of products.
Effects of Working Pressure on the Microstructure and Properties of ZnO Thin Films Prepared by DC Magnetron Sputtering
Authors: Gao Fei , Liu Xiao Yan , Zheng Li Yun , Li Mei Xia , Jiang Rui Jiao
Published: April 2012

ZnO thin films were prepared by DC magnetron sputtering. The effects working pressures on the microstructure, optical properties and the photoluminescent properties were studied. The results show that ZnO thin films were successfully prepared with preferred orientation growth, showing structure of single crystal. The transmission of all the ZnO thin films kept above 85%. With increasing the working pressure, the surface of ZnO thin film became coarse, the intensity of X-ray diffraction peak decreased and the transmission of the film decreased and then increased. The intensity of the two photoluminescence peak of ZnO thin films one ultraviolet peak at 400 nm and one blue peak at 466 nm increased with increasing the working pressure. The ultraviolet peak was originated from the transition emission of the electrons from the conduction band to the valence band while the blue peak was originated from the defects in ZnO thin films.
The Analysis of the Interface States of Low-Density Materials in the Forming Process
Authors: Wang Qiao Li , Zheng Yu Dong , Liang Xin , Ling Ying , Qiao Kun , Kang Yong Lin , Zhu Guo Ming
Published: April 2012

The interface of two low-density materials is bent in the forming process, which decreases the performance of materials. The theoretical analysis of the interface state in the forming process was taken to solve this problem, and the results indicated that the viscosity of the low-density material was very important to the interface state. The finite element simulation was also used to investigate the factors that affect the interface state. The results revealed the viscosity of material and the pressure were the main factors that affected the interface state; the stress and displacement at the interface could be accurately predicted by the finite element models. The ultimate aim was to modify the relevant parameters in a way that could obtain the required interface states.
Research on Properties of Automobile Lubricant Containing Nano-Ceramic Additives
Authors: Zhao Yan Hui , Dai Xi Liang , Zhang Jia Xi
Published: April 2012

This paper makes road test on two kinds of engine lubricant, one contains nano-ceramic additives, and one does not. Results show that the lubricant containing nano-ceramic additives can fully meet the requirements of automotive engine, and nano-ceramic lubricant is superior in anti-wear properties to other lubricant in experiment, and nano-ceramic additives can improve the anti-wear properties of lubricant.
Effect of N+ Ion Beam Exposure on the Secondary Structure of Horseradish Peroxidase
Authors: Xu Qiang
Published: April 2012

After the horseradish peroxidase (HRP) was treated with different dose of N+ ion beam, the effect of N+ ion beam on the secondary structure of HRP was studied by FTIR(Fourier-transformation infrared spectroscopy). The results have shown that different dose ranging from 1015 to 1016 ions/cm2 has different effects on the secondary structure contents the HRP. The N+ implantation induce the mutual change in the secondary structure unit of HRP. It was suggested that N+ ion beam was bound to result in conformational change.
Ultrasonic Fatigue Tests on a High Strength Steel for Welded Structure
Authors: Peng Wen Jie , Qiu Bao Wen , Li Rong Feng , Xue Huan
Published: April 2012

In this paper, the ultrasonic fatigue machine which works at frequency of 20kHz is utilized to conduct the ultrasonic fatigue tests on a high strength welding structural steel with symmetric cycle stress R=－1 at room temperature. Two typical specimen geometries are tested: smooth specimen and notch specimen. The fatigue tests of smooth specimen are also carried out on the electromagnetic resonance equipment at conventional frequency. A comparison is made between the fatigue test results at the ultrasonic and conventional frequency.
Simulation Research on Acoustic Emission Signal of Tank Corrosion
Authors: Yu Yang , Yu Yang
Published: April 2012

This paper studies the cylindrical acoustic emission signal generation, propagation and attenuation. Acoustic emission signal is a form of elastic waves and mechanical waves also. The large finite element physics simulation software COMSOL is used to simulate the propagation of acoustic emission signals coursed by the oil tank bottom corrosion. Simulation is divided into two parts，they are separately two-dimensional simulation and three-dimensional simulation. The bottom part of oil tank is two-dimensional simulation and the entire tank is three-dimensional simulation. Two-dimensional simulation is achieved in different situations. Strength of point source are the same in different positions, and the same point source position has different intensity. Acoustic emission wave propagation has a greater relationship with the media of dissemination, the point source position and the different interfaces.
Study on Engine Kinematics and Dynamics Simulation Based on COSMOSMotion
Authors: Liu Xiao Xu , Chen Min , Tang Ai Hua
Published: April 2012

The engine model with 4 cylinders is built by SolidWorks, the kinematics and dynamics simulations of the engine virtual prototype are done by COSMOSMotion, the results of kinematics simulation are checked, there are very small errors between the simulation results and the calculation results according to formulas. The mainly results of dynamics simulation are given. The simulation result consists with the parameters of the engine.
Design of Cross Slide Safety Devices in Engine Lathe
Authors: Xu Yue Zeng , He Qun Ying , Hu Wei Xin
Published: April 2012

It presents the design of overtravel protection device for engine lathe C6140.When the cross slide runs to the limit position,the stop dog touches the contact blade of limit switch, which cuts off the power supply of machine and provides protection for lathe.The experiment proved that the device is reliable.
Research on Modular Division Method of CNC Machine Tool
Authors: Sheng Zhong Qi , Zhu Zong Xiao , Shi Xiang Dong , Zhang Chao Biao
Published: April 2012

Modular division is the first step of modular design, which also is the premise and basis of modular design. Whether modular division is reasonable can directly affect the systemic function performance and the cost of modular products. This paper introduces a new sort of modular division method, which divides the modules by calculating the correlations among sub-functions. At last, taking the high-speed CNC turning center as example, which is made by Shenyang Machine Tool Group, this paper proved the effectiveness and feasibility of the method.
The Analyze of Shear Force Calculation Model of Drum Type Linear Blade Flying Shear
Authors: Li Yu Gui , Ye Quan , Wang Gao Ping , Fan Fei
Published: April 2012

In this paper, the shear force in the shearing process of the drum type linear blade flying shear is done. Two different approaches were taken to establish the shear force formula, and then the finite element simulation. The comparison results of the calculated values and simulated values can be seen that as the thickness increases, the maximum shear force calculated by the pure shear force formula increases rapidly, the shear force calculated by the energy release rate formula is relatively small, and the finite element simulation values and calculated values close to each other when the plate thickness is small. The derived formula in this paper not only can be applied to complex engineering problems, but also has provided a theoretical basis for drum type linear blade flying shears on the shear force calculations and equipment design.
The Dynamic Strength Analysis the Key Parts of Body of RG
Authors: Zhao Yan Jun , Huang Xing Ming , Li Shu Guang , Xu Cheng
Published: April 2012

Structure design and material selection of weapons is the key of the weapon design. The dynamic strength are studied of the weapon’s key parts by finite element simulation in Elastic plastic mechanics. The results show that the body can withstand the maximum pressure, and the simulating results are well coincident with the experiment ones, which confirms the reliability and availability of the virtual prototype model advanced here. Current research work will be helpful in further this kind of designers to select material and the frame optimization design.
Vibration of a Misaligned Rotor System with Asymmetric Shaft Stiffness
Authors: Feng Sheng , Geng Hai Peng , Qi She Miao , Yu Lie
Published: April 2012

Vibration characteristics of a misaligned rotor with asymmetric shaft stiffness are studied. The system consists of two shafts connected by a flexible coupling with parallel misalignment, two rigid disks attached at the middle of each shaft and one of the shafts has asymmetric stiffness. The governing ordinary differential equations are derived using Lagrange dynamics and integrated through numerical methods. The effects of asymmetry, eccentricity and misalignment are studied through the peak-to-peak lateral vibration amplitude at different rotor speed. Simulation results show that the amplitude peaks at the natural frequency associated with unbalance and parallel misalignment, while half the natural frequency associated with the asymmetric shaft stiffness. This study may contribute to enrich understanding of the vibration of a rotor system under the cases of eccentricity, parallel misalignment and asymmetric shaft stiffness.
Steel-Cylinder Yielding Analysis of PCCP with Broken Wires
Authors: You Ri , Gong Hong Bo
Published: April 2012

The prestressing wires of prestressed concrete cylinder pipe (PCCP) provide pipe wall with compressive stress to resist internal pressure. Broken wires may cause yielding of steel cylinder and increase the risk of pipe failure with time. In order to reveal the mechanism of steel-cylinder yielding in PCCP with broken wires, a simplified model is developed and the maximum number of broken wires to preclude exceeding limit stress in steel cylinder can be determined conveniently by the equations derived in this paper. Verification analysis shows that the solution of simplified model agrees well with that of nonlinear finite element analysis. By comparing the calculated maximum number of broken wires with the detected actual number of broken wires, steel-cylinder yielding in prestress loss zone can be predicted, thus aiding condition assessment of PCCP
Motion Simulation and Analysis of the Biped Robot
Authors: Xu Ying , Duan Shou Yong , Lei Ya Chao
Published: April 2012

A new idea, method and technology are provided for research on complex kinematics and dynamics of a biped robot using computer simulation technology. The virtual prototype of the biped robot, created by Pro/ENGINEER, is put into ADAMS and setting material, fixed joints, revolute joints, contact forces, frictions, torque and gravity are implemented for the virtual prototype to carry out dynamics simulation. The calculation of testing curve is conducted with ADAMS/PostProcessor to acquire trajectory curve of each component of mass center for the biped robot with respect to time. The trajectory curve is imported into Matlab to get space trajectory curve of mass center and its parameterized equation through functional curve fitting trajectory curve.
Multi-Fields Simulation Model for Micro-Machined Capacitive Accelerometer
Authors: Dai Qiang , Xu Bin , Yu Jia Xin , Jiang Gang , Song Dan Lu , Cai Yong
Published: April 2012

To cope with the multi-physics fields simulation in MEMS device, based on PSPICE software, a multi-fields simulation model of capacitive micro-accelerometer is proposed, in which the mechanics, thermal and electric fields are included. Through the comparison of maximum step and pulse acceleration response under large displacement condition, which are obtained by simulation model and classic formula respectively, it is indicated that the difference between them is less than 3%. Furthermore, the comparison has been done with sensitivity test results in open loop mode. The comparison results show that the difference is less than 5% for large displacement situation and 3% for little displacement situation. Hence, the model could basically accomplish multi-physics fields simulation in MEMS device and be helpful in further research.
Dynamic Characteristics Design of the Grinding Machine Bed
Authors: Wang Ke , Song Guang Min , Sun Xing Wei
Published: April 2012

In order to analyzing the dynamic characteristics of the machine bed totally and grasping the dynamic parameters accurately, I make the use of conventional method to design fine-long rods machine firstly and research with FED dynamic property that machine in the processing . I use the FED method to find the region of defect and build the method of optimization. Dynamic property of Rib has affect bed of machine directly. The thesis would change and optimize rib. At the same time, they act as target of optimization and improve the dynamic property of bed with FED and achieve it. The thesis has offer evident of theory for changing bed.
Study on the Key Technologies for Clouding Manufacturing Based on Virtualization Technology
Authors: Fu Song Yin , Gong Song Chun , Chen Zheng
Published: April 2012

Currently our country is vigorously developing the modern service industry, in which the manufacturing service constitutes an important part and the cloud manufacturing is a kind of modern manufacturing mode for the realization of the manufacturing services. This paper first analyses the definition of cloud manufacturing, and then emphatically analyses the core technology of cloud manufacturing. As virtualization technology is the core supporting technology for cloud manufacturing, this paper conducts a detailed analysis on the application of the virtualization technology in cloud manufacturing. Finally, this paper summarizes and proposes the prospect of the cloud manufacturing technology.
The Finite Element Analysis of Rotor Contact Strength for a High-Speed Traction Motor
Authors: Xiang Hui Yu , Hu De Mao , Leng Chong Jie , Gong Yan Jue
Published: April 2012

In order to evaluate the contact strength of a type of high-speed train traction motor rotor，in this paper, for the high speed test train traction motor under the five working conditions, Based on the established motor rotor 3D model, NX.Nastran environment, the contact pressure between rotor and lamination is analyzed by the finite element and got the stress intensity distribution on the rotor. The five working condition include starting, constant work starting condition, rated, short circuit condition, the highest speed condition. The result shows that for the high speed tractor motor, in the starting conditions, and won't appear rotor shaft and laminated relation between slip. The finite element method is useful to do the contact strength analysis, and thus to improve the design efficiency, increase the reliability of the product, and lay the foundation for the latter design optimization.
Kinematic Forward Solution Analysis of the 3-PRS Parallel Robot
Authors: Huang Jun Jie , Kang Jian Li , Zhao Jun Wei
Published: April 2012

It is always hot and difficult to research kinematic forward solutions of the Parallel robots .In the paper according to the trait of 3-PRS parallel robot, the three freedom degrees are analyzed by using helix theory, which include one prismatic freedom degree along z axis and two rotation freedom degrees along and axis. The movement equation of the motion platform center is given on this basis, then the example is programmed by making use of Matlab software, in the end the kinematic forward solutions are gained. The method is in common use and is suitable for other type parallel robots. This also provides the reference value for control strategy
Thermal Optimization on High-Power LED Street-Lighting Driver with Micro Heat Pipe
Authors: Chen Chuan , Lu Long Sheng , Fu Qiu Gang
Published: April 2012

High-power LED street-lighting with advantages including long lifespan, great luminescent efficiency, lower power consumption and superior environmental performance has received more and more attention. However, the lifespan of corresponding LED drivers fails to match with that of LEDs. The main reason is that in tight and confined spaces, high heat flux cannot be emitted to surroundings, which lead to the increased temperature of electric devices in LED driver. In this paper, high conductive micro heat pipes (MHPs) are applied in the cooling system. Firstly, the Icepak thermal simulation software is applied in analog contours of temperature of interior driver. Then experiments are carried out to measure the temperature of electric devices of LED driver. The results indicate that internal temperature of LED driver is decreased by 5°C when MHP is applied, compared with the original thermal design. The capacitor and MOSFET which are sensitive to heat and easy to damage run under optimized temperature.
Modeling of Multi-Phase Solid State Reactions-Case of IMC Growth
Authors: Pawełkiewicz M. , Danielewski Marek , Janczak-Rusch Jolanta , Wierzba Bartek
Published: April 2012

The formation of intermetallic compounds (IMC) at the solder-substrate interface is required to initiate the metallurgical bond. However, rapid growth of IMCs may degrade joint strength through i) the increased presence of a low toughness phase, ii) the consumption of the solderable surface (void formation) and iii) generation of primary and secondary stresses. Knowledge of mass transport and reaction processes during joint formation and service life are essential for solder system design. The mathematical description of inter-and reactive diffusion in open system presented here is based on Darken method (bi-velocity), involving the different molar volumes in the system and Wagner boundary conditions. It combines the interdiffusion, reactive diffusion and the effective flux constraints to couple processes occurring at different time scales. The rCADiff software serves as a tool to simulate simultaneous growth of the two Cu-Sn IMCs.
Fractal Dimension of Grain Boundary during Heating Comparison between Images Analyses and Monte Carlo Simulation
Authors: Bigerelle M. , Favergeon Jérôme , Iost Alain
Published: April 2012

There are few articles that mention fractal dimension in grain growth mechanism. Some authors build a simplified analytic model showing that initial fractal dimension of grain boundary has an influence on interface modification velocity. Nevertheless they postulate the relation where L is the grain length, c is a constant, s is grain size and the fractal dimension. The aims of this paper is to experimentally analyze by image analysis the fractal dimension of A5 aluminum sheet grain boundaries during heating and to simulate their evolution by a Monte Carlo method to validate experimental data.. It is shown by Monte-Carlo simulation and confirmed experimentally that the grain growth process decreases the fractal dimension of grain border. It can be concluded that it is very hazardous to build a model of grain growth without including the effect of grains morphology. The macroscopic fractal morphology of the grain structure could then be used to validate microscopic relation between Monte Carlo Steps time and real time.
Grain Boundary Diffusion. Effect of Segregation or Concentration Dependence of Diffusivity
Authors: Rodin Alexey , Dolgopolov Nikolai , Kryukov Sergei
Published: April 2012

Effect of microalloying of Al by Ce on Cu grain boundary diffusion (GBD) in Al and other results of GBD study in metals with different purity were analyzed. It is shown that in dependence on the chemical composition of the matrix the triple product of GB diffusion can be higher or less than that for pure metals. The main concept used for description of the results is local ordering of the atoms (including atomic complex formation and appearance of «poisonous» places around atoms of the alloying element). The increasing of atom mobility at GB is discussed also in terms of solidus temperature changes.
Iodine Volume Diffusion Measurements in Uranium Dioxide
Authors: Pizzi E. , Garcia Philippe , Carlot G. , Palancher H. , Maillard S. , Pasquet B. , Roure I. , Pozo C. , Maurice C.
Published: April 2012

The presence of iodine in UO2 has a great impact on nuclear fuel behaviour, both during-in reactor operation or under long-term repository conditions. Here the volume diffusion coefficient of iodine is studied using a methodology which involves ion implantation, annealing under different oxygen potentials and SIMS (Secondary Ion Mass Spectroscopy) for the concentration profile characterization of samples. The changes in the initial concentration profile induced by annealing are interpreted using Ficks second law to determine the diffusion coefficient. The first part of this paper is devoted to the description of the applied methodology. The iodine diffusion coefficients in the bulk are shown to depend upon the annealing temperature and oxygen potential. In smaller grained polycrystalline samples, the SIMS signal is averaged out over several grains and therefore, the analysis of the depth profile changes in samples due to annealing may be efficiently compared to depth profiles in as-implanted samples. By contrast, in Cr-doped UO2 samples in which the grain size is larger than the zone analysed by SIMS, a particular methodology has to be developed. To this end, large grained material was examined using EBSD (Electron Back Scattering Diffraction) in order to determine the relative crystalline orientations of the grains. Following iodine implantations, various grains with different orientations were studied using SIMS. An attempt is presented at correlating the different sputtering rates with the various grain orientations.
Modelling Fission Gas Bubble Distribution in UO2
Authors: Skorek Richard , Maillard Serge , Michel Amélie , Carlot Gaëlle , Gilabert Eric , Jourdan Thomas
Published: April 2012

The Cluster Dynamics method is assessed for the investigation of fission gas behaviour in a krypton-implanted and annealed UO2 sample. The simulation results are then compared to Thermal Desorption Spectroscopy (TDS) data. A release mechanism is proposed: the initial burst is related to krypton migration via an interstitial mechanism, while the second stage of the release process can be accounted for by the diffusion of krypton in a substitutional position. This latter mechanism is compatible with a diffusion coefficient of 4.10-21 m²/s.
Molecular Dynamics Study of Grain Boundary Diffusion of Fission Gas in Uranium Dioxide
Authors: Govers Kevin , Lemehov Sergei E. , Verwerft Marc
Published: April 2012

Among the various products originating from fission events, the noble gas elements Xe and, in a lesser extent, Kr present important fission yields. The accumulated gas inventory in its various states (e.g. atomically dissolved, precipitated in cavities or released from the fuel) has a strong impact on the performance of LWR fuel and is presently one of the limiting factors for fuel burnup extension. A more fundamental understanding of fission gas behaviour at the atomic scale would enable to improve the modelling of the various mechanisms ultimately leading to fission gas release and to refine conservative safety margins. Lots of efforts have already been undertaken using atomistic computer simulations, ab initio calculations and Empirical Potential Molecular Dynamics (EP-MD) techniques, that relate to the bulk behaviour. This article will discuss EP-MD investigations in nanosized polycrystalline UO2, constructed from Voronoi cells in a 3-D periodic environment. This study has focused on Xe diffusion at and close to grain boundaries.
A Density Functional Study of Oxygen Mobility in Ceria-Based Materials
Authors: Frayret Christine , Villesuzanne Antoine , Pouchard Michel , Mauvy Fabrice , Bassat Jean Marc , Grenier Jean Claude
Published: April 2012

In CeO2-based solid electrolytes, it has been shown that point defects are directly responsible for oxygen ionic conduction. The ionic conductivity is strongly affected by the anion vacancy concentration which is enhanced by doping with aliovalent cations. When rare earth sesquioxides such as La2O3, Gd2O3, Sm2O3, Y2O3 are added to CeO2, the dopant cation substitutes for the cerium ion, and oxygen vacancies are created for charge compensation. Incorporation of trivalent dopants into CeO2 at the Ce4+ sites can be depicted by the following defect reaction (expressed in Kröger-Vink notation):
Elaboration of Uranium Monocarbide Samples for Diffusion Studies
Authors: Fiquet O. , Da-Silva L. , Garcia-Ferre F. , Brothier M. , Carlot Gaëlle , Garcia Philippe , Martin Guillaume , Barthe Marie-France
Published: April 2012

Mixed Uranium-Plutonium Carbides are candidate fuels for 4th generation nuclear reactors. In this frame, a research program is underway at CEA (French alternative and atomic energies commission) to gather basic properties of such material to get a better understanding of in-pile behaviour. In the field of solid state physics, the measurement of transport properties and in particular diffusion coefficient requires the preparation of uranium carbide samples with very specific characteristics: very low oxygen content, mono-phased UC, high density (greater than 95% of the theoretical one), coarse microstructure, accurate samples geometry. In this paper the Process development is presented to manufacture such samples and the specific equipments which have been set up in glove-box. Characterizations of the first samples are also given.
Recycling, Recovery and Improvement of Properties of Ceramic Tile Manufacturing by Adding Two Types of Glass in Clay Mixtures
Authors: Chemani Halima
Published: April 2012

Today, recycling industrial waste plays a major role in our society. Waste is used as additive in the production of a certain number of products. It enables to reduce the costing price per piece and to enhance some of the properties of the material, and to reduce pollution problems. To meet the various criteria, and manufacturing requirements of contemporary ceramic tile and bring a solution to our environment, an addition of waste glass from lamps public lighting and neon (cullet) is incorporated in various ceramic masse for substituted a feldspar. A comparative study is made between the properties obtained with each type of waste on the one hand and the other with the properties of tile produced in the industry. It was found that the tiles made with waste glass lighting lamps offer higher mechanical strength than that obtained with the feldspar and a good agreement between the shard - enamel. Although the value of strength obtained with the waste of neon is lower than that obtained with the first type of glass. The latter always remains higher than that of industrial value.
Influence of Water Vapour on a Nickel-Based Alloy Oxidation
Authors: Buscail Henri , Rolland Raphaël , Issartel Christophe , Riffard Frédéric , Rabaste Françoise , Perrier Sébastien
Published: April 2012

Water vapour has little effect on the oxidation rate and scale composition of a nickel-based SY 625 alloy oxidized between 900 and 1100°C. At 900 and 1000°C, the outer scale is composed of Cr2O3 and a continuous NbNi4 - Ni3Mo subscale is found at the oxide/alloy interface. At 1100°C the scale is composed of an outer chromia scale and an internal CrNbO4 subscale. The oxide scale morphology differs between dry and wet conditions. Under dry conditions the oxide scale appears to be compact and chromia pegs are observed at the internal interface. Under wet conditions, porosities are observed inside the scale. At 1100°C some scale spallation is observed under dry and wet conditions.
Grain Boundary Diffusion, Stresses and Segregation
Authors: Bokstein Boris S.
Published: April 2012

A short review of the most important reliable, as well as doubtful, in authors opinion points in a wide field of grain boundary diffusion, stresses and segregation.
Corrosion of Valve Steels in Combustion Gases of Diesel Engines under Thermal Shock Conditions
Authors: Grzesik Zbigniew , Adamaszek Krzysztof , Jurasz Zbigniew , Mrowec S.
Published: April 2012

The corrosion behavior of four valve steels (X33CrNiMn23-8, X50CrMnNiNbN21-9, X53CrMnNiN20-8 and X55CrMnNiN20-8) in combustion gases of fuel oil, containing different bio-component concentrations of (5 and 10 wt. %) has been studied under thermal shock conditions. It has been found that the addition of bio-components to the fuel oil decreases the corrosion resistance of all steels under investigation, this effect being the stronger, the higher was the concentration of bio-component addition. It has been shown, that in spite of bio-component addition, the X33CrNiMn23-8 steel containing the highest chromium concentration, behaved much better than three remaining steels due to the formation of the highly protective chromia scale.
Influence of Water Vapour on Isothermal and Thermal Cyclic Oxidation Conditions of a Nickel-Based SY625 Steel at 1100°C
Authors: Rolland Raphaël , Buscail Henri , Issartel Christophe , Riffard Frédéric , Rabaste Françoise , Perrier Sébastien
Published: April 2012

In isothermal oxidation condition, water vapour has little effect on the oxidation rate and scale composition of a nickel-based SY 625 alloy oxidized at 1100°C. The scale is composed of an outer Cr2O3 and an internal CrNbO4 scale. The oxide scale morphology differs between dry and wet conditions. Under dry conditions the oxide scale appears to be compact and chromia pegs are observed at the internal interface. Under wet conditions, porosities are observed spread inside the scale and the chromia grain size is smaller. At this temperature some scale spallation is observed under dry and wet conditions. Under cyclic oxidation conditions the oxide scale adherence is slightly improved in wet environment. The chromia scale is adherent during the 4 first oxidation cycles. In dry air, spallation occured after the first cycle. In dry and wet conditions, after the chromia scale spallation has started, NiO and NiCr2O4 form first. NiMoO4 forms later on the alloy surface during the cycling test. The best resistance of the alloy under thermal cycling conditions under wet conditions is related to the presence of a more plastic and adherent scale owing to a higher scale porosity and smaller chromia grain size compared to dry conditions.
Determination of Oxygen Diffusion Coefficient in Oxidation Films of the AISI 439 Ferritic Stainless Steel
Authors: Sabioni Antônio Claret Soares , Malheiros Emiliane Advíncula , Ji Vincent , Jomard François
Published: April 2012

In order to investigate the role of oxygen diffusion in the oxidation process of the AISI 439 ferritic stainless steel, oxygen ion diffusion coefficients were determined, for the first time, in oxide films formed by the oxidation of this steel. Steel samples were firstly oxidized from 750o C to 900o C, in synthetic air, in order to grow oxide films mainly made up of chrome oxide; the oxygen diffusion experiments were then performed using the stable isotope 18O as oxygen tracer. The introduction of the 18O in the oxide film was performed by means of the gas-solid isotopic exchange method, in the temperature range of 750-900o C, in Ar+21%18O2 atmosphere. The 18O diffusion profiles were established by secondary ion mass spectrometry (SIMS). Parabolic oxidation constants calculated by means of Wagner´s theory, using the oxygen ion diffusion coefficient determined by our experimental process, are greater than oxidation constants previously determined in oxidation experiments from 850 to 950º C, in air, which indicates that the oxygen ion diffusion is large enough to assure the growth rate of the oxide film formed by the oxidation of the AISI 439 steel in these temperatures.
Effect of Phosphoric Acid Treatment on Isothermal High Temperature Oxidation Behaviour of AISI 304 Stainless Steel at 800°C
Authors: Riffard F. , Buscail Henri , Rabaste F. , Issartel Christophe , Perrier Sébastien
Published: April 2012

Phosphoric acid treatment is used as a way to improve the high temperature oxidation resistance of a chromia-forming AISI 304 steel. Chromia-forming steels are excellent candidates to resist to high temperature oxidizing atmospheres because of the formation of protective oxide scales. The oxide scale growth mechanisms are studied by exposing phosphoric acid-treated and untreated 304 steel samples to high temperature conditions in air. The analyses were carried out by means of thermogravimetry, and in situ X-ray diffraction (XRD). The experimental results show that the phosphoric acid treatment does not have a beneficial effect on cyclic high temperature oxidation (up to 70h of the oxidation test) of AISI 304 steel because of growth of a layer mainly formed by external cation diffusion which grows very quickly. The isothermal high temperature oxidation of this steel at 800°C in air shows a very fast initial iron oxidation towards the external interface, allowing to chromium element to be more available to the internal interface to form a continuous chromia layer, thus causing the establishment of a parabolic oxidation regime and leading to a beneficial reduction of the oxidation rate (after 70h of the oxidation test).
Plasma Assisted Diffusion in Porous Materials: Experiments, Modeling and Applications
Authors: Brault Pascal , Bauchire Jean Marc , James François , Josserand Christophe
Published: April 2012

Plasma sputtering deposition of platinum on porous substrates is a relevant way for building high performance catalytic thin films. The knowledge and control of platinum density adsorbed in the porous medium, during deposition, are of primary importance. We show that the experimental concentration depth profiles originate from a superdiffusion phenomenon. Moreover experimental results are well described by a classical porous-fractal diffusion model, for which diffusion coefficient is also time-dependent, even if such a model does not include the proper physical mechanisms.
Assessment of the Gas Permeation through Thin Coated Polymeric Membranes; Improvement of the Gas Barrier Ability for Hydrogen Storage
Authors: Chapelle David , Feng Li Ping , Nardin Philippe , Rauch Jean Yves
Published: April 2012

We investigate and simulate the permeation behavior of PET membranes on which thin coatings are deposited. Depending on the parameters of deposition and on the thin coating thickness, we assume this alteration could make it possible to decrease by one order of magnitude the permeation coefficient. Some specific developments have been necessary, all the more not only a decrease of permeation is expected but also the mechanical strength of the thin coating during severe mechanical loadings. We consequently design devices dedicated to the permeation test but also to the bulge and blister tests which permit to check the mechanical properties of the film and its adhesion on the PET surface. This paper focuses on the permeation test.
Diffusion and Redistribution of Boron in Nickel Silicides
Authors: Blum Ivan , Portavoce Alain , Chow Lee , Hoummada Khalid , Mangelinck Dominique
Published: April 2012

The Diffusion and Solubility of B Implanted in δ-Ni2Si and Nisi Layers Is Studied by SIMS. it Is Observed that both Diffusion and Solubility Are Higher in δ-Ni2Si than Nisi. the Redistribution of B during Ni Silicidation Is Also Studied. the SIMS Profiles Show the Presence of Concentration Step in the Middle of the Final Nisi Layer. this Profile Shape Is Explained in Light of the Results Obtained in Preformed Silicides. the Proposed Model Is Supported by Redistribution Simulations that Can Reproduce the Main Features of the Profile.
Entropy Production and Stress–Deformation Effect on Interdiffusion
Authors: Danielewski Marek
Published: April 2012

A general, consistent with linear irreversible thermodynamics, theory of stress and elastic deformation during interdiffusion is shown. Special consideration is given to the entropy balance and its production rate during diffusion in Cu-Fe-Ni alloys. The entropy produced during diffusion does not depend on the reference frame and is always positive. The paper spans the gap between the Darken method, linear irreversible thermodynamics and treatments by Stephenson and Svoboda.
Diffusion Mechanism in XSi2 and X5Si3 (X= Nb, Mo, V) Phases
Authors: Prasad Soma , Paul Aloke
Published: April 2012

In view of the importance of the silicides in the high temperature applications, the diffusion behaviour is compared in different systems for two types of silicides, XSi2 and X5Si3 (X=Nb, Mo, V). Atomic mechanism of diffusion and defects present in the structure are discussed. In both the phases, Si has faster diffusion rate than the metal species. This is expected from the nearest neighbour (NN) bonds present in the XSi2 phase but rather unusual in the X5Si3 phase. Relative mobilities of the species calculated indicate the presence of high concentration of Si antisites. Moreover, the concentration of the defects is different in different systems to find different diffusion rates.
Nitrogen Diffusion at Low Temperature in fcc Materials Deformed by Attrition Peening
Authors: Thiriet T. , Czerwiec T. , Hertz D. , Marcos G. , Toll-Duchanoy T. , Migot S. , Brugier B. , Foucault M. , Belmonte T.
Published: April 2012

Recent scientific work has opened new fields of application to mechanical treatments such as shot blasting or peening. Indeed, it has been shown that this treatment, performed before a nitriding treatment on the surface of ferrous alloy, lowers processing temperatures and significantly increases the diffusion kinetics. We undertook to test this combination of mechanical pretreatment and thermochemical treatment on stainless steels and nickel-based alloys. The mechanical treatments were done by surface attrition peening. The pretreated samples were then nitrided at low temperature using remote plasma. In this paper, the results obtained after nitriding treatments on samples treated by attrition peening are compared to those nitrided only. The use of X-ray diffraction, microhardness measurement, observations by optical and scanning electron microscopy, texture analysis by EBSD (Electron BackScatered Diffraction) and measurement of nitrogen concentration profiles by SIMS (Secondary Ion Mass Spectrometry) allows quantifying the effects of the combined treatments.
SIMS Analysis of Deuterium Absorption and Diffusion in Austenitic Fe-Mn-C Steels
Authors: Dieudonné T. , Marchetti Loïc , Jomard François , Wery M. , Chêne J. , Allely C. , Cugy P. , Scott C.P.
Published: April 2012

Austenitic Fe-Mn-C steels are Ultra High Strength Steels which may be used for the production of deep drawn automotive parts containing extremely high residual stress and strain levels. In consequence, hydrogen absorption occurring during the corrosion process in aqueous environments may enhance the sensitivity of these steels to different kinds of hydrogen-induced damage, in particular Stress Corrosion Cracking (SCC). In order to predict and prevent SCC, it is important to study the behaviour of hydrogen in these austenitic steels exposed to aqueous environments and in particular the dependence on the alloy chemistry and microstructure. SIMS profiles of deuterium introduced by cathodic charging in selected specimens were used to characterize the diffusion of hydrogen in these steels. This allowed to be studied the role of chemical composition and microstructure on the kinetics of H absorption at room temperature. The competition between bulk matrix diffusion and short-circuit diffusion phenomena along grain boundaries was investigated. The results show a strong dependence of H diffusion and distribution on the alloy chemistry and grain size.