bluuebunny/crossref_metadata_2025 huggingface dataset:
The Optimization Design of Laser Welded Sandwich Plate Structure
Authors: Sun Yu Ping , Li Jin , Teng Zun Li
Published: December 2011

Height lightweight is one of key technology to dock structure that is made up of the sandwich composite board and satisfy requirements of bending rigidity feature. This paper proposes a new engineering optimization method which is both precision and economical. First, through theoretical calculation, to get bending stiffness( , ) and twist stiffness( ). Afterwards ,based on structures bending theory ,we could get the stiffness equation of the model , and calculate the quality equation of the model equations. Supposed the maximal stiffness as objective function ,height(h) of rib and space of rib(a) as design variable.Using MATLAB software and ABAQUS finite element software, we could get the Optimized design program that is to meet the requirements of the structural characteristics of sandwich composite panels of the dock structure. In 100 tons load, when the length of plate is 1m, thickness of plate is 4mm, the height of the rib is 40 mm, the spacing of the rib is 75 mm, and when the height is 45 mm, the spacing is 95 mm, the bending performance of the whole mode lis betterand the quality is more lighter.
Preparation of Highly Exfoliated Epoxy/Clay Nanocomposites by the Method of Ultrasonication Dispersion-Microwave Cure
Authors: Wang Kun Yan , Zhou Shi Yang , Jiang Zhen , Zhu Xiao Qing
Published: December 2011

A new ultrasonication dispersion – microwave cure (UD-MC) method for preparing highly exfoliated layered epoxy/clay nanocomposites was developed. The process was divided into two consecutive stages. In the first stage, the epoxy and organoclay were mixed by high stirring and ultrasonication in the presence of acetone. In the second stage, the mixture of epoxy and organoclay was cured with microwave of 400W and postcured at 135°C. The microstructure of the nanocomposites was characterized with X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results indicated that the basal spacing of the organoclay particles in the epoxy/clay mixture was significantly enlarged, up to around 75Å afther the ultrasonic treatment. The layered clay was highly exfoliated under the microwave energy; and the basal spacing of nanolayers was more than 90Å.
Effect of Metal Intercalating on Transmission Characteristics of One-Dimensional Photonic Crystal
Authors: He Bei Jia , Chen Xin Yi , Wang Jian Bo , Lu Jun , Chang Jian , Liu Dong
Published: December 2011

To expand the bandgap's width of the one-dimensional photonic crystal, a crystal named SiO2/Metal/MgF2 is formed by joining some metals into the crystal SiO2/MgF2. Furthermore the Finite Difference Time Domain (FDTD) method is used to explore the metals' influence on the crystal's transmission characteristics. The simulation results show that the metals joined could expand the width of the one-dimensional photonic crystal's bandgap effectively and the bandgap's width increases when the metals' thickness increases. Meanwhile the bandgap's characteristic is affected by the metals' material-characteristic. The higher the plasma frequency is, the wider the bandgap's width will be and the more the number of the bandgaps will be. On the other hand, the metals' damping frequency has no significant effect on the bandgap, but would make the bandgap-edge's transmittance decrease slightly.
The Characteristic of the Coating Prepared on Magnesium Alloy AZ91D by Micro-Arc Oxidization
Authors: Shang Wei , Wen Yu Qing , Qin Yan Yun , He Fang , Fang Ji Yun
Published: December 2011

Micro-arc oxidation coating on AZ91D magnesium alloy is prepared in a NaAlO2-NaOH-montmorillonite-acacia gum electrolyte solution with adaptive electric parameters. The morphologies, composition, phase component of the coatings are analyzed by SEM, EDS and XRD. And CHI600B electrochemistry workstation is employed to investigate the corrosion resistance of the coatings. The results show that the MAO coating has the relatively uniform in thickness. The coating is mainly composed of MgO and MgAl2O4 phases. It provides corrosion protection by acting as a barrier. The MAO coating enhances the corrosion resistance of the magnesium alloy AZ91D to some extent.
Primary Study on Electron Beam Surfi-Sculpt of Ti-6Al-4V
Authors: Wang Xi Chang , Gong Shui Li , Guo En Ming , Zhao Hai Yan , Xu Heng Dong
Published: December 2011

Electron beam surfi-sculpt is a new metal surface processing technology, which is potentially used in many areas. In this paper, forming mechaniam of electron beam surfi-sculpt has been investigated by experiments and numerical simulation. Electron beam surfi-sculpt of Ti-6Al-4V was realized by a new control system and a innovative hexagon scanning waveform. At the same time, microstructure of protrusions was analysed. All the results of experiments and simulation show that forming mechanism is the interaction of vapour pressure and surface tension, but surface tension plays a dominant role during electron beam surfi-sculpt process.
Reliability Laboratory Analysis of PCB Surface Coating Based on ENEPIG
Authors: Yu Jin Wei
Published: December 2011

Electroless palladium are introduced to ENEPIG surface coating technology, from reaction principle to prevent oxidation of nickel-plated, but the process conditions and parameters of practical application are whether or not mass-produce condition , need using a series of reliability experiments to validate it , to reduce risk coefficient of mass-produce , to satisfy customer requirement. Therefore, put forward a package of experimental programs, including experiment projects, experiment methods, instrument and equipment for test, evaluate requirement, test result and analysis etc , especially using TEM have in-depth analysis for interface alloy compound of ENEPIG coating player with SAC305 , systematically verified ENEPIG production technology are mature and reliable, it is considered to be versatile surface coating technology, and particularly suitable for application in gold bonding and surface mount hybrid assembly board which are high connecting reliability product, completely replace the current ENIG technology.
Effect of Refractory᾽s Thermal Conductivity on the Thermal Stress Field of the COREX Gasifier Top
Authors: Xue Wen Dong , Huang Xiao Xiao , Xie Jing , Cui Xing Da
Published: December 2011

The top of COREX-3000 gasifier was numerical simulated and investigated the relationship between thermal conductivity and the thermal-stress field. It is concluded that when the thermal conductivity of the working lining and permanent lining is respectively 0.95W / (m•K) and 0.5 W / (m•K), the change rate of the top stress along radical direction is minimum.
Characterization of Ceramic Coatings on ZL114 Aluminum Alloy Prepared in Alkaline Electrolyte Adding Nano-Al2O3 by Micro-Arc Oxidation
Authors: Zhao Jun , Xi Jian Jun
Published: December 2011

ZL114 aluminum alloy samples were treated by micro-arc oxidation using alkaline solution added different amount of nano-Al2O3 to improve the surface properties. Effects of the additives were investigated by thickness, hardness, morphologies and corrosion performance. The results indicated that proper amount of nano-Al2O3 had certain contribution with higher corrosion performance. And adding too much nano-Al2O3 decreased the property of ceramic coatings.
Optimization of Process Parameters for Electroless Ni-P Plating on AZ91D Magnesium Alloy by Phosphate Pretreatment
Authors: Jia Su Qiu , Guan Jing Xin , Zhao Zhan Kui , Chen Hua , Jia Shu Yan
Published: December 2011

Electroless nickel plating coatings on AZ91D alloy by phosphate pretreatment were prepared. The coating resembles a cauliﬂower and is compact. It consists of amorphous Ni-P. Potentiodynamic polarization curves of the Ni-P coatings in 3.5% NaCl show that the electroless Ni-P coating improves the corrosion resistance of AZ91D alloy and the highest corrosion potential reached to -0.513V vs. SCE. The results of the orthogonal experiment of process parameters indicates that temperature 80°C, time 120min and pH 7.5 can be considered as the optimum process parameters for electroless Ni–P plating on AZ91D alloy and pH value in the bath has more effect on corrosion potential than temperature and time.
A Surface Melting Infiltration Study on Cast Magnesium Alloy
Authors: Liu Zhao Ming , Quan Gao Feng , Zhang Ying Bo
Published: December 2011

A new technique has been developed by infiltration during casting process to AZ91D magnesium alloy part. Through a melting process a alloyed surface layer was formed on the surface of the part in casting process, and the surface layer helps improve the corrosion resistance. The macro morphology, thickness, microstructure and properties of the layer were analyzed by digital, scanning electron microscopy, spectroscopy and corrosion measurement system. The results show that a uniform and dense infiltration layer on the surface of AZ91D part was obtained. This technique can fundamentally change the physical and chemical properties of magnesium alloy parts. More importantly, it is low-cost, green and environmental protection.
Technical and Structure Study of Coprecipitation Method for Nano-Titanium Dioxide
Authors: Wen Feng , Chen Ying Qun , Cao Yang , Lin Shi Wei
Published: December 2011

Nano-titanium dioxide (N-TiO2) have already been studied and applied in the different fields due to its special surface, quantum size effect and high photocatalysis etc super properties. As a kind of biomaterials, biocompatibility and corrosion resistant of titanium are closely related to the surface oxide films. In this paper, nano-titanium dioxide with uniform granularity was synthesized using coprecipitation method. The effects of reactant mixture ratio and sintering temperature on synthesized N-TiO2 were discussed. X-ray diffraction and Fourier transform infrared spectroscopy were employed to analyze structure of N-TiO2. The results showed that prepared N- TiO2 were all anatase and rutile coexistence and the larger ratio of carbamide to titanium oxysulfate (CO(NH2)2/TiOSO4) is propitious to formation of metatitanic acid (TiO(OH)2) precipitate. Meanwhile, with CO(NH2)2/TiOSO4 increasing, the start time and end time of precipitate decreased. The method used in this paper was a kind of simple process and easy to do.
Study on Preparation and Performance of γ-Ray Protection Coating
Authors: Zhou Yuan Lin , Zhu Xiao Na , Li Ying Jun , Zheng Shao Tao , Li Li
Published: December 2011

A kind of novel protective coating was prepared by using super-hydrophobic PbWO4 nanocrystals as functional stuffing. The samples were characterized systematically by means of scanning electron microscope (SEM), contact angle analyzer, atomic force microscope (AFM) and Fourier transform infrared spectroscopy(FT-IR). The effects of various amount of nano-PbWO4 particles on shielding ratio to 59.5 keV γ-ray were also discussed. The results revealed that the average diameter of PbWO4 nanocrystals were about 32nm. The contact angle between the modified PbWO4 and water was amounted to 153.08°, which showed that the modified PbWO4 owned super hydrophobic surfaces. The modified PbWO4 had good dispersion and stability in organic solvents. Chemistry reaction happened between components of coatings and nano-PbWO4 particles, thus it showed good compatibility with binders. The shielding ratio to γ-ray was up to 32%, and the hardness and levelling property was greatly improved.
Optimization of Diamond-Coated Drawing Dies for Stainless Steel Tubes Based on the FEM Simulation
Authors: Lin Zi Chao , Shen Bin , Sun Fang Hong , Zhang Zhi Ming , Guo Song Shou
Published: December 2011

Diamond-coated drawing dies are considered as ideal drawing dies for their unique characteristics, such as high hardness, wear resistance and low friction. In order to utilize the superior characteristics of diamond coatings towards improving the drawing performance, the nonlinear FEM simulation is used to simulate the whole stainless steel tube hollow sinking process, with 2D axi-symmetric elastic-plastic element. Based on the simulation results, the distributions of the axial stress and radial stress are analyzed, the influence of parameters of drawing dies on the diameter shrinkage is investigated. Optimal die parameters are obtained.
Study on the Preparation and Properties of Low Permeability Coating
Authors: Li Ying Jun , Zhou Yuan Lin , Luo Shi Kai , Li Li , Zheng Shao Tao
Published: December 2011

Fluorinated amorphous carbon (a-C:F) films have long attracted much consideration due to their low surface energy, hydrophobicity, low refractive index, good electrical and thermal insulation and good thermal stability, and so on. To repair of some polymer films that have good flexibility and low permeability, F2314 resin was used as main film-forming material of coating in this paper. The solubility parameter of F2314 was estimated by group contribution method, which is 20.548 J1/2•cm-3/2. And proper solvents were selected on the basis of the solubility parameter. FEVE resin was selected as one of the components of coating, because of its good adhesion and compatibility. The adhesion of the F2314 coating was improved, and penetration resistance performance of F2314 coating was enhanced to 300(mg•mm)/(m2•h).
Enhancing the Sinterability of Chemically-Derived Tl1212 Superconducting Powders Using Nano-Sized MgO as Sintering Aid
Authors: Salleh Faizah Md. , Yahya Ahmad K. , Haji Jumali Mohammad Hafizuddin
Published: December 2011

The superconducting Tl0.8Bi0.2Sr2Ca0.8Y0.2Cu2O7 powder prepared from chemical route was mixed with varying amounts of nano-sized MgO powders (x=0 to 0.50 wt. %) to form bulk superconducting composites. XRD results show that the addition of 0.15 wt.% nano-MgO is accompanied by an increase in 1212-phase and the disappearance of SrCO3 impurity. SEM investigations revealed more regular-shaped and smaller grains microstructure for MgO added samples in contrast to MgO-free sample which revealed irregular shaped grains. EDS showed homogenous distribution of Mg for all MgO-added samples with the exception of x=0.50 where agglomeration of MgO particles were observed. However, MgO added samples exhibit lower zero-resistance critical temperature, Tc zero than the MgO-free sample.
Hygrothermal Characterization of Porous Building Materials-Experiment Research on Isothermal Sorption and Capillary Problem
Authors: Yu Shui , Zhang Xu
Published: December 2011

The research on water vapor isothermal sorption of porous building materials have an important function on controlling and solving hygrothermal problems, such as durability, thermal insulation, mold growth and indoor air quality, when building materials are in hygrothermal environment, especially in the high humidity environment. The isothermal sorption is used to describe the maximum moisture sorption capacity, if moisture content exceeds the limitation, probably there will be liquid water appearance, which lead to the risk of mold growth, decreasing durability and increasing thermal conductivity, and so on. The classic testing method of isothermal sorption could be found in ASTM Standards C 1498-01. In this paper, the eco-stucco, eco-fiber batt and eco-fiber board is tested using traditional method. Meanwhile, pore size distribution and capillary condensation is analyzed which is challenge for the design basis of hygrothermal character for the building envelope.
The Influence of Argon Flow on Inclusion Characteristic and Fatigue Life of Continuous Casting Bearing Steels
Authors: Hsu Chin Chuan , Chung Ho Hua
Published: December 2011

In this study, scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) are used to measure the inclusion size and identify the inclusion type respectively. The evaluated maximum nonmetallic inclusion size of bearing steel has been obtained by using statistics of extreme values (SEV). The influence of argon flow of the continuous casting process on the inclusion characteristics of bearing steels has been estimated, the influence of size and type of inclusion of bearing steel on its fatigue life have been discussed as well. It was found that most inclusions in steels are oxysulfide and alumina cluster. With the decreasing of the argon flow, the inclusion size gets larger and the amount of cluster-type inclusion also increases. In addition, by adopting the criterion of return period (T) at 200, the serial analyses show that the relation between predicted inclusion size for max and the argon flow is inverse proportion, but the fatigue life of steel is proportional to argon flow. A correlation among argon flow, inclusion size and fatigue life of bearing steel has been established in this study.
Research and Evaluation on the Planning and Sanding Properties of Mytilaria laosensis
Authors: Su Chu Wang , Yuan Quan Ping , Su Ning Chuan , Huang Jin Da
Published: December 2011

In this paper, the planning and sanding properties of Mytilaria laosensis, compared with Castanopsis hystrix, were tested. The properties were conducted according to the criteria ASTM D1666-87. The results show as follow: the planning and sanding properties of Mytilaria laosensis and Castanopsis hystrix all show excellent; in the evaluation system for full marks 5 points, the planning marks of Mytilaria laosensis and Castanopsis hystrix was separately 4.8 points and 4.7 points, and the sanding marks was separately 4.47 points and 4.3 points, so the planning and sanding properties of Mytilaria laosensis were slightly better than Castanopsis hystrix; feeding speed had remarkable influence on the planning properties of Mytilaria laosensis and Castanopsis hystrix; The wood quality had important influence on the sanding properties.
Fatigue Analysis of the Drill String According to Multiaxial Stress
Authors: Zhang Jian Bing , Lv Xiang Hong
Published: December 2011

To find out the cause for fatigue failure of a drill string used in oil field drilling, and considering the actual working conditions, axial, radial and circumferential cyclic stresses borne by the drill string in borehole of oil and gas well, fatigue strength of drill string is analyzed based on multi-axial fatigue assessment method. Then the formula to calculate the mean stress of multi-axial load of the drill string is obtained, and the formula serves as a method to calculate multi-axial fatigue life of the drill string, which has been verified through field data. It is realized that multi-axial stress has significant influence on drill string fatigue. When on drill string fatigue, Soderberg equation shall be employed to calculate the stress amplitude of drill string fatigue.
Contact Performance Study of Modified Spur Bevel Gear Considering Assembly Error
Authors: Xu Peng Fei , Tian Xi Jie , Cui Huan Yong
Published: December 2011

By modifying the profile of spur bevel gear，the load fluctuation in transmission process can be effectively reduced, the contact area of the gear pair can be greatly improved, and the stress distribution of gear teeth also can be controlled. However, during the actual work, many factors may influence gear work performance. This paper considers the influence of assembly error on contact performance of gear in mesh, builds the assembly error mathematical model of modified spur bevel gear, and deduces the parameter equation of modified tooth profile curve. Then dynamic contact simulation analysis is carried out by applying ANSYS/ LS-DYNA software, the distribution of the stress and strain of bevel gear pair in different shaft angle deviations is accurately obtained.
Self-Assembly Fabrication of the Polymer p-n Junction Film
Authors: Tan Nai Di , Zhang Yan Lin , Fan Xi Wu , Asano Noriko , Toda Masayuki , Olihara Katsuo
Published: December 2011

The p-n junction film which consists of the conductive polymer of p type semiconductor of polyhexylthiophene (PAT-6) and n type one polyquinoline(PQ) was fabricated by self-assembly by applying novel stratified phase separation phenomenon that had been discovered previously by us. The film showed ideal characteristic I-V relationship of the diode device
Preparation and Ammonia Sensing Properties of PANI-TSA/PA6 Core-Shell Nanofibers by Electrospinning
Authors: Pan Yi Jun , Dong Xian Jun , Wei Qu Fu , Hung Wei Min , Lin Chao Yu , Ho Yi Hsing , Hsieh Chien Teng
Published: December 2011

PANI-TSA/PA6 core-shell nanofibers were prepared via the electrospinning process with a PA6/formic acid solution and the chemical polymerization of PANI doped with p-toluene sulfonic acid (TSA) on the surface of the PA6 nanofibers. Their structure and morphology were examined by FE-SEM and FTIR and the fabrication mechanism and ammonia sensing properties of the PANI-TSA/PA6 nanofibers were also investigated. All the results showed that, composite nanofibers with PANI-TSA shell and PA6 core had been prepared successfully, which showed a good potential in ammonia sensitivity application.
Research on Intelligent Synchronization Control of Erecting System Driven by Two Hydraulic Cylinders
Authors: Gao Qin He , Guan Wen Liang
Published: December 2011

The synchronization control problem of a large equipment erecting system driven by two oil cylinders side-by-side is analyzed. A closed loop control scheme of hydraulically driven erecting system based on electro-hydraulic proportion control valve is given. Considering the existence of time-varying parameters of hydraulic system, intelligent PID control algorithm is implemented by adding neurotic adaptive element control approach to improve the adaptive control capacity of the controller. Simulation results show that the intelligent PID control algorithm is more effective than conventional method for the erecting system synchronization control.
Exact Solution of the Plane Flow with Unsteady Vortex and Brownian Motion
Authors: Yu Wei Wei , Guo Xuan
Published: December 2011

Based on the proposed conception”pseudo-potential” of the incompressible plane flow, an exact solution to the Euler’s equation is given, f can be arbitrarily given potential force. It is proved that the given solution can describe the infinitely many unsteady vortices distributed periodically on the whole plan with the Melnikov function. It is obviously that the Brownian motion appearing along the border region separating different vortices.
Key Issues in Microscale Temperature Sensing with Thermocouple Array
Authors: Sun Wei Qiang , Liu Hai Xiao , Xu Sheng Yong
Published: December 2011

Precise local temperature measurement is important for research on failure analysis of integrated circuits, micro/nano-fluidics, chemistry reactions in confined geometry, biological and biochemical reactions, etc. Thermocouple arrays are believed powerful for local temperature sensing at the microscale with high spatial, temporal, and temperature resolutions. And, as a passive device, a thermocouple array can often be embedded in a complicated solid device, providing real-time temperature information of critical regions of the device. In this work, we will discuss in detail some key issues of temperature sensing at the microscale by using thermocouple arrays, in terms of material, fabrication, calibration, measurement, time-resolvable mapping, and potential application.
The NURBS Interpolation Based on Machining Dynamics
Authors: Jiang Lei , Wang Yu Lan
Published: December 2011

This article presents a new NURBS interpolation of tool path according to the requirements of machining dynamics, so the NURBS interpolation can satisfies the dynamics condition of the machine. The experimental results confirm that the proposed NURBS interpolator is capable of achieving a satisfactory performance, reducing the impact, machine vibration of feed, and improving the surface accuracy and quality of machining.
Development of Downhole Tools for Stratified Testing in Oil and Gas Open-Hole Wells
Authors: Zhao Quan Min , Fan Jian Chun , Yan De , Tian Rui Rui , Zhou Bo , Li Chun
Published: December 2011

In view of the problems that multilayer stratified sampling and acidification-testing operations cannot be done in drill stem multilayer testing for open-hole wells, downhole tools for acidizing and testing were developed, stratified testing and sampling string, acidizing-testing string and their construction technology in open-hole wells were also studied. A set of technologies and equipment were provided for open-hole testing in exploratory wells. Field application shows the studying of drill stem stratified testing technology and related technological equipment can solve the problems existing in production, raise the working efficiency of open-hole testing, accelerate the speed of oil and gas exploration, and reduce the operating expenses.
Controller Design and Analysis of Networked Control Systems with Time Varying Uncertainty
Authors: Ding Gang , Liu Jin , Sun Lian Kun
Published: December 2011

A class of networked control systems (NCSs) with time varying uncertainty in the plant was investigated. A new kind of stochastic communication logic based on the current value of the estimation error was proposed. Some new criteria for the asymptotical stabilization of such systems have been established. The asymptotic stability condition of the systems was established by Lyapunov theory. A numerical example was demonstrated the efficiency of the obtained result.
Cellular Neural Network Based on Hybrid Linear Matrix Inequality and Particle Swarm Optimization for Noise Removal of Color Image
Authors: Su Te Jen , Cheng Jui Chuan , Lin Yu Jen
Published: December 2011

This paper presents a color image noise removal technique that employs a cellular neural network (CNN) based on hybrid linear matrix inequality (LMI) and particle swarm optimization (PSO). For designing templates of CNN, the Lyapunov stability theorem is applied to derive the criterion for the uniqueness and global asymptotic stability of the CNN’s equilibrium point. The template design is characterized as a standard LMI problem, and the parameters of templates are optimized by PSO. The input templates are obtained by employing the CNN’s property of saturation nonlinearity, which can be used to eliminate noise from arbitrary corrupted images. The demonstrated examples are compared favorably with other available methods, which illustrate the better performance of the proposed LMI-PSO-CNN methodology.
On a Dual Model with Multi-Layer Dividend Strategy under Stochastic Interest
Authors: Yin Jin Sheng
Published: December 2011

In insurance mathematics, a compound Poisson model is often used to describe the aggregate claims of the surplus process. In this paper, we consider the dual model of the compound Poisson model with multi-layer dividend strategy under stochastic interest. We derive a set of integro-differential equations satisfied by the expected total discounted dividends until ruin. The cases where profits follow an exponential distributions are solved.
Design of Double-Deck Household Vertical-Axis Wind Generator
Authors: Wu Yu Chi , Lu Cheng Lung , Huang Chun Chen , Lin Jing Yuan , Chen Meng Jen , Chen Wen Shiush , Chiang Hsien Yin
Published: December 2011

Wind power has been recognized as one of the important green energy resources in Taiwan. However, installing large-capacity wind generators needs to meet many environmental regulations, limiting the penetration of wind power to households/communities. In this paper, the design of a novel double-deck vertical-axis wind generator for households is presented, hoping “many a little makes a mickle” and making better use of green energy to reduce carbon emission. The proposed wind generator is an axial-flux permanent-magnet (PM) synchronous generator, which design is different from other existing wind generators in several aspects: (1) double decks for double wind turbines vs. single turbine, (2) silicon-steel-lamination-cored vs. air-cored for armature coils, and (3) axial-flux PM generator vs. conventional PM generator. The performance of the proposed design is simulated with the aid of a finite element software package. The experimental results are consistent with the simulation. The prototype of the proposed wind generator is also compared with a commercial mini wind generator on the market. The proposed wind generator produces satisfactory results.
On-Call Duty and RCM Maintenance of Hydropower Plants
Authors: Xue Yu Feng
Published: December 2011

The management based on technical aspects of hydropower indicates a proper understanding of the technology, so in this article the regulation of management is involved in the technology, on-call duty, to deal with the safe operations and reliability-centered maintenance of the plants.
Elastic-Plastic Analysis of the Circle-Castellated Steel Beam Using Finite Element Method
Authors: Li Jun , Xiang Jia Wei
Published: December 2011

The elastic-plastic behavior of the circle-castellated steel beam is analyzed using finite element method. Stress distribution, expansion of plastic zone and flexural deflection are investigated under two simulation loads of the uniform pressure and concentration force. The results show that this kind of beam provide references for us to strengthen structural bear capacity.
Texture, Grain Boundaries, Defects and Location of Substitutional Atoms in Cryo-Mechanically Processed Ti-5Ta-1.8Nb Alloy
Authors: Dasgupta Arup , Basu Joysurya , Parida P.K. , Vadavadagi B.H. , Saroja S. , Vijayalakshmi M. , Jayakumar Tammana
Published: December 2011

An α-β alloy (β~8% in the stress relieved condition) of Ti-5Ta-1.8Nb has been subjected to severe plastic deformation (SPD) by cryo-rolling. The grain size of α-Ti could be reduced significantly from ~ 8µm to 100 nm and less by cryo-rolling. Extensive plastic deformation leads to grain fragmentation through the formation of defect clusters. The fragmented grains exhibit deformation texture. High resolution transmission electron microscopy (HRTEM) confirmed the presence of low and high angle grain boundaries. The role of substitutional atoms (Ta, Nb) in producing lattice strains and altering the projected potential from the atomic columns has been discussed. Although, the minor phase, β (bcc-Ti) is evident in the starting alloy, it was not observed after SPD, possibly due to extended solid solution formation (Gibbs–Thomson effect) in the fine grains or due to the stress induced transformation of the α-Ti phase.
Texture Evolution in ARB Processed Commercial Purity Aluminium
Authors: Miyajima Yoji , Kashioka Daisuke , Tsuji Nobuhiro
Published: December 2011

Texture of the ARB processed commercial purity aluminium was investigated in order to explore the stable component in rolling texture more than 95 % of rolling reduction in FCC metal sheets having high stacking fault energy. Weak location dependence along normal direction was observed in the sheet up to ARB 8 cycle, whereas the texture could be regarded to be uniform after ARB 8 cycle. The main orientation was Copper component, whereas the minor orientations were Brass and S orientations in the ARB processed pure aluminium sheets rolled up to around 99.9 % reduction.
Prediction of the Plastic Anisotropy of Rolled Sheets under a Combined Effect of Texture, Grain Shape and Grain Size
Authors: Delannay Laurent
Published: December 2011

The present study explores a way to improve predictions of the mechanical anisotropy of textured polycrystalline aggregates. The underlying hypothesis is that grain-shape-dependent backstresses developed during the elastic-plastic transition influence the selection of active slip systems inside individual grains. Recently, a model was developed and applied successfully to electro-deposited pure iron with a columnar grain structure \cite{Delannay2011}. In the present study, we first suggest another definition of the boundary separation distance experienced by individual slip systems. Then, the model is adapted from the case of spheroidal grains, considered initially, to the more general situation of ellipsoidal grains. A combined effect of grain size, grain shape and texture on plastic anisotropy at yielding is illustrated in case of a rolled IF steel sheet.
Classification of Textures and Microstructure Stability in Rolled F.C.C. Metals with Grain Interactions
Authors: Ray Atish K. , Diak Bradley J.
Published: December 2011

A novel experimental investigation of both high and medium stacking fault energy bi-crystals of aluminum and copper, respectively, show that orientation, grain interaction and material are all key factors in the stability of some ideal rolling texture components. Ideal {110} or {112} orientations obtained from high purity aluminum or copper single crystals were embedded within a {110} crystal orientation of the same material and reduced 60 percent by channel die compression at room temperature. Spatial misorientations developed inside the deformation bands were analyzed using SEM-based EBSD. The presence of long-range orientation gradients in some of the crystals revealed the interacting nature of polycrystalline deformation. From the results it is proposed that f.c.c. polycrystalline grains can be classified according to their stability and susceptibility to deformation: (i) stable and interacting; (ii) unstable and interacting; (iii) stable and non-interacting; (iv) unstable and non-interacting.
Texture Evidences of Interaction between Plastic Deformation and Phase Transformations in Zr-Based Alloys
Authors: Perlovich Yuriy , Isaenkova Margarita , Fesenko Vladimir , Krymskaya Olga
Published: December 2011

Abstract. Features of the texture development in Zr-based alloys under compression at tempera-tures of the (α+β)-region of the Zr-Nb phase diagram indicate that the plastic deformation shifts temperatures of phase transformations due to accompanying thermal effects and the decrease of lattice stability, whereas formation of the fine-grained structure by phase transformation promotes activation of the non-crystallographic deformation mechanism of slip by interphase boundaries.
Formability Changes of Asymmetrically Rolled AA 3003 Al Alloy Sheets
Authors: Lee Jin Hyuk , Kim In Soo
Published: December 2011

Formability and mechanical properties of metal sheets are related to on their textures. It has been studied to improve the formability and change the texture of the AA 3003 Al alloy sheets after asymmetric rolling. Asymmetrically rolled Al sheets are shown the high intensity of the distorted cube texture, {001}, distorted rotated cube texture, {001}, weak γ-fiber, ND//, {123}, {120} and {120} components. After the asymmetrically rolled AA 3003 Al alloy sheets, the plastic strain ratios of the asymmetrically rolled Al alloy sheets were about 1.7 times higher than those of the initial Al sheets. The variation of plastic strain ratios of the asymmetrically rolled Al alloy sheets could be related to the change of texture components through asymmetrical rolling in AA 3003 Al sheet.
Deformation Behavior of Electro-Deposited Pure Iron with Extremely High R-Value
Authors: Sugiura Natsuko , Yoshinaga Naoki
Published: December 2011

Electro-deposited pure iron has a quite sharp and isotropic <111>//ND fiber texture and a needle-shaped grain elongated in ND. This pure iron shows an r-value exceeding 7, which is difficult to explain from the texture alone. In this study the deformation behavior of electro-deposited pure iron was investigated to reveal the mechanism behind the extremely high r-value. The post-deformation surface slip lines indicated that the particular <110> plane slips, which are perpendicular to ND, exclusively act in the specimen. The tensile deformation caused by this slip system does not require any decrease in thickness, hence the extraordinary high r-value is mainly attributable to this limitation of the active slip system. Presumably, the needle-shaped microstructure affected the limitation of the slip system.
Effect of Texture on the Mechanical Properties and Ballistic Performance of an Extruded Al-6063 Rod
Authors: Jena Pradipta Kumar , Ponguru Senthil P. , Siva Kumar K. , Singh A.K.
Published: December 2011

The present work describes the influence of texture and mechanical properties anisotropy on ballistic performance of an Aluminium-6063 extruded rod. It has been observed that the centre region of the extruded rod exhibits better strength, elongation and charpy impact values than the peripheral region. Texture of the extruded rod is measured from centre towards the periphery. A significantly variation in texture has been observed from the centre towards the periphery. Ballistic experiments are conducted on 80 mm thickness extruded samples by impacting them with 7.62 mm armour piercing projectile at 0° angle of impact at 840±15 m/s velocity. Results show that the centre of the extruded rod displays much improved ballistic performance than the periphery, which has been attributed to the strong {111} fibre texture present at the centre.
The Cube Texture Revisited
Authors: Hutchinson Bevis
Published: December 2011

The cube texture in rolled and annealed fcc metals and alloys has long fascinated metallurgists because of its high symmetry and extreme sharpness. This paper demonstrates and analyses the texture perfection that is developed in a copper sample. Reasons that have been advanced to explain the development of the texture during recrystallisation and grain growth are discussed. Orientation selectivity is favoured during growth but more particularly in the nucleation stage. Especial attention is paid to the rapid recovery which cube oriented crystals undergo on heating after plane strain deformation and which is the basis for its uniquely preferential nucleation. Various metallurgical factors are known to affect the strength of the cube texture in practice and explanations for some of these are presented.
Effects of Grain Orientations on Nanoindentation Behavior in Hexagonal Zirconium
Authors: Lodh Arijit , Samajdar Indradev , Tewari Raghvendra , Srivastava Dinesh , Dey Gautam Kumar , Pant Prita
Published: December 2011

The present study deals with nanoindentation behavior of commercial Zircaloy 2 and high purity (5N purity) crystal bar Zirconium. The effect of crystal orientation was studied through high resolution electron diffraction, while a finite element model was developed to extract yield strength and strain hardening exponent from nanoindentation data. The study brings in clear signatures of orientation dependence of mechanical properties in hexagonal Zirconium.
Ultra-Fine Grained Al-SiC Metal Matrix Composite by Rotary Swaging Process
Authors: Giribaskar Sivaswamy , Gouthama  , Prasad Rajesh
Published: December 2011

In present study microstructural evolution during swaging on aluminium alloy based metal matrix composite (MMC) reinforced with 15% volume fraction silicon carbide (SiC) particles is presented. Samples were swaged at room temperature in steps with reducing die dimensions using rotary swaging technique. SEM and TEM are used to study the microstructural characteristics of swaged samples. SEM observations were made to understand the flow and deformation characteristics of deforming aluminium matrix in the presence of second phase and reinforced SiC particles during swaging. TEM observations on swaged samples confirmed the formation of ultra-fine grains in Al-15%SiC MMC. It is shown that the dynamic recrystallisation occurring in the proximities of second phase particles during the deformation at room temperature, leads to very fine grained microstructure.
Formation Process of {001} Texture in Al-Cu Solid Solution during High Temperature Compression Deformation
Authors: Okayasu Kazuto , Takahata Shinsuke , Fukutomi Hiroshi
Published: December 2011

Uniaxial compression tests were conducted on Al-2.3mass%Cu and Al-4.6mass%Cu alloys under strain rates and temperatures ranging from 1.0×10-4s-1 to 5.0×10-2s-1 and 723K to 803K, respectively. Texture measurements reveal that main component of the fiber texture changes from {001} + {011} to {001} depending on the deformation conditions. EBSD measurements reveal that grain structure separates into large grains without subgrains and small and large grains with subgrains after the deformation at 803K under a strain rate of 5.0×10-2s-1 up to a strain of -1.0 in Al-4.6massCu alloy.
Gradient Microstructure of FeCr30Co8 Hard Magnetic Alloy Subjected to Plastic Deformation by Complex Loading
Authors: Korneva A. , Bieda-Niemiec M. , Korznikova G. , Korznikov A. , Sztwiertnia Krzystof
Published: December 2011

Magnetically hard Fe-Cr-Co-based alloys are distinguished by their good ductility, excellent magnetic properties and low cost. Their superior magnetic properties are obtained by magnetic treatment and multistage tempering, which results in spinodal decomposition of the solid solution into the isomorphous α1 and α2 phases. However, the α1+α2 microstructure causes a reduction in the plasticity and strength of the material. It can often be advantageous for permanent magnets to maintain fine magnetic properties throughout their volume along while retaining good mechanical properties only in the subsurface layer. To improve the mechanical properties of the latter, FeCr30Co8 samples were deformed in tension combined with torsion. Loading was applied at 750°C, which ensured that the conditions for superplastic deformation were fulfilled. Here, we present the results of microstructure investigations of the samples treated in the aforementioned manner. Observations of the longitudinal section of the samples showed the formation of a gradient microstructure with the maximum grain refinement in the surface layer and the characteristic rotation of the elongated α phase grains from positions nearly perpendicular to the tension axis at the surface to positions tilted at approximately 45º to the tension axis inside the material. Deformation at superplastic conditions also activated precipitation of the σ intermetallic phase, particularly in the areas of highest deformation. The refinement of the microstructure and precipitation of the σ-phase resulted in a significant increase in hardness at the surface of the FeCr30Co8 samples.
Influence of Friction Stir Processing Parameters on Anisotropic Behavior Property of 5086-O Aluminum Alloy
Authors: Pradeep Shivanna , Sharma Sumit Kumar , Pancholi Vivek
Published: December 2011

In the present work, 5086 Al alloy is subjected to single and multi pass friction stir processing (FSP) to modify microstructure and mechanical anisotropy. The processing is carried out at constant rotation speed of 1025 rpm and different traverse speeds of 30 mm/min and 50 mm/min with and without cooling. Mechanical anisotropy is evaluated in terms of normal and planar anisotropy by performing tensile test in 0, 45 and 90o direction to processing direction. Material processed using multi pass FSP at 30 mm/min is showing lower planar anisotropy as compared to base material. The mechanical anisotropy property is correlated with the development of micro texture.
Role of Texture in Understanding Creep Flow in HPT-Processed Ultrafine Grained Copper
Authors: Leuthold Jörn , Wegner Matthias , Divinski Sergiy V. , Padmanabhan K. Anantha , Setman Daria , Zehetbauer Michael J. , Wilde Gerhard
Published: December 2011

Disks of copper samples were produced by High Pressure Torsion (HPT). Specimens for tensile creep experiments were cut from the disks and subjected to creep deformation at 348 K to obtain elongations greater than 30%. Electron backscatter diffraction (EBSD) was used to analyze the texture after HPT deformation and after additional tensile elongation.
Texture Studies of Superplastically Deformed Electrodeposited Nanocrystalline Ni and Ni-P Alloy
Authors: Prasad M.J.N.V.
Published: December 2011

Nanocrystalline Ni and Ni-P alloy with grain size down to 6 nm were processed by pulsed electrodeposition. The as-deposited materials, possessing a strong fiber texture, were tested in tension at different temperatures and strain rates. Both materials exhibited low temperature superplasticity but with significant differences in mechanical characteristics. In comparison with nano-Ni, the nano Ni-P alloy exhibited significant strain hardening in flow behavior and lower superplastic elongations at relatively low strain rates, although the grain size was finer at test temperatures with limited grain growth in nano Ni-P alloy. Texture study as a function of strain and strain rate by bulk X-ray Schultz reflection and electron back scattered diffraction (EBSD) revealed development of cube components {001} and {013} with negligible deformation texture components (Cu or brass type) and limited fraction of low angle grain boundaries (< 10 %) in superplastically deformed samples. The reasons for the formation of cube components and their influence on flow behavior of electrodeposited materials were critically analyzed. Additional microstructural investigation by transmission electron microscopy revealed dislocations movement constrained by intragranular particles, leading to strain hardening and cavitation in the nano Ni-P alloy.
New Insights into Cube Nuclei in Deformed Aluminium
Authors: Albou A. , Quey R. , Maurice Claire , Raveendra S. , Samajdar Indradev , Dawson Paul R. , Driver Julian H.
Published: December 2011

The formation of Cube oriented elements in plane strain compressed aluminium has been studied by EBSD for both hot and cold deformations. By following the orientation changes of the same set of 176 grains deformed at 400 °C up to a strain of 1.2 using a split sample, it is shown that about 15% of the grains can break up into several regions of very different orientations, characterized by very large orientation gradients. In particular those grains oriented within about 30° of Cube develop Cube oriented zones in contact with other rolling texture components. Finite element crystal plasticity simulations confirm this mechanism of creation of Cube by plastic deformation. The same type of microstructure can also be observed after heavy cold rolling (strain of 2.3), but at a scale that is much finer by at least an order of magnitude. In this case the micron-sized Cube fragments are located along many grain boundaries or in some particular grains. When the cold deformed sample is annealed, EBSD observations of the same areas reveal that the intergranular Cube fragments are very efficient recrystallization nucleation sites, apparently since they possess mobile high angle boundaries with the local environment.
Effects of Initial Parameters on the Development of Cube Texture during Recrystallization of Copper
Authors: Lin Feng Xiang , Pantleon W. , Leffers T. , Jensen Dorte Juul
Published: December 2011

A series of oxygen free high conductivity copper samples with different initial grain sizes, cold rolling conditions and storage times as well as slightly different impurity contents was used to investigate the effects of these initial parameters on the development of cube texture during recrystallization. For rolling reductions of 90% and 95%, cube textures with volume fractions between 3% and 50% were observed. Higher rolling reduction led to a stronger cube texture. Cube texture development is very sensitive to the initial grain size before rolling. In general, fine grained material gives a strong cube texture after recrystallization, and the requirement on fineness of the grain size may vary for materials with different purity. Large sample widening during rolling can largely inhibit the development of cube texture after recrystallization. Neither storage time, nor the slight change in impurity content had large effects in the present investigation.