bluuebunny/crossref_metadata_2025 huggingface dataset:
In-Plane Thermoelectric Generator of Carbon Nanotube Membrane Driven by Thermal Gas Flow
Authors: Lu Jiang Lei , Wang Guang Long , Sun Lian Feng , Gao Feng Qi , Chen Jian Hui , Yu Fang , Wang Gang , Wang Hong Pei
Published: November 2012

The in-plane thermoelectric generator (TEG) was ingeniously designed when the thermal gas flowed over the carbon nanotube (CNT) membrane at the modest speed of a few meters per second. It was composed of the glass substrate, aurum electrodes and CNT membrane synthesized by a floating catalyst chemical vapor deposition method. In the air under atmospheric pressure, the experimental results showed that the maximal output voltage could reach 1.7 mV. It related not only with the temperature difference between the hot-side and cold-side, but also the temperature gradient of the CNT membrane which was closely dependent on the velocity and temperature of the gas flow. The multi-physical power mechanism was applied to interpret the energy conversion, which included the coupling relation of the fluid dynamics, heat transmission and Seebeck effect. This novel method could effectively enhance the output voltage, extend the applied range of TEG and had a fine prospect.
Failure Analysis on Spring of Boiler Drum Safety Valve
Authors: Feng Yan Ting , Sun Peng , Xu Xue Xia , Chen Hong Bin
Published: November 2012

Safety valve is an important component of a boiler. The failure of its spring will bring hidden trouble to the boiler operation. The fracture failure of a drum safety valve spring of a power plant boiler was discussed based on chemical composition analysis, hardness test, metallurgical microstructure observation and SEM. Results showed that improper material selection and improper heat treatment process which led to temper brittleness contributes to the fracture. In addition, oxygen corrosion pit on the surface of the spring play an important role in promoting the cracking.
Effect of Initial Grain on Mechanical Properties of AZ31 Alloy during Warm Forming
Authors: Wang Qiang , Zhang Zhi Min , Zhang Xing
Published: November 2012

Plane strain compression were carried out for as-cast and pre-strained AZ31 alloy specimens at 210～330°C. The influence of initial grain on strengthening effect was analyzed by means of metallographic examination and mechanical testing. The results indicate the recrystallized grain of Mg alloy is sensitive to initial grain. With the deformation temperature increasing, the ultimate tensible strength decreases for as-cast and pre-strained alloy. With the deformation degree increasing, the tensile strength presents an increasing trend for as-cast alloy, but the tensile strength decreases on the whole for pre-strained alloy. The tensile strength increments of ～50% can be achieved under appropriate processing conditions.
Analytical Procedure for Geometrical Evaluation of Flat Surfaces Formed by Multiple Indentation Processes
Authors: Bernal C. , Camacho Ana Maria , Reina José M. Arenas , Rubio Eva María
Published: November 2012

Elementary indentation processes are relatively simple compression processes and they are quite extended in many fields of the industry. Nevertheless, the concatenation of these processes is a new approach and has interest from a technological point of view. In this work the geometry of multiple indentation processes is analyzed on flat surfaces. The state of the formed surface by several types of tools is studied and a model has been developed in order to quantify by means of shape parameters the quality of the theoretical surface depending on the technological and geometrical characteristics of the process.
Effect of Starting Powders on Microstructure and Properties of Silicon Nitride Nanoceramics
Authors: Jiang Hai , Tian Chun Yan
Published: November 2012

Silicon nitride nanoceramics were fabricated by hot press sintering two kinds of Si3N4 nano-sized powders. The effect of starting powders on microstructure, mechanical properties and thermal shock resistance were investigated. The microstructure of sintered materials consists of spherical grains and the addition of α–Si3N4 to starting powders does not affect the grain morphology. The flexural strength, fracture toughness and thermal shock resistance increase with the increase in amount of α–Si3N4 starting powders, and the maximum mechanical properties are obtained when the amount of α–Si3N4 powders is 40wt.%. The hardness values decrease with the increase of α–Si3N4 amount.
Effect of GaN Cap Layer on the Electrical Properties of AlGaN/GaN HEMT
Authors: Guo Han , Tang Wu , Zhou Wei , Li Chi Ming
Published: November 2012

The electrical properties of AlGaN/GaN heterojunction high electron mobility transistor (HEMT) are simulated by using sentaurus software. This paper compares two structures, the HEMT with GaN cap layer and the HEMT without GaN cap layer. The sentaurus software simulates the DC and AC characteristics of the two AlGaN/GaN HEMT structures. The HEMT with GaN cap layer can increase the maximum transconductance gm from 177ms/mm to 399ms/mm when the doping concentration of the cap layer is 3×1018cm-3 compared with the other structure under the same conditions. The simulation results indicate that the HEMT with cap layer can increase maximum transconductance gm, saturation current Ids, current-gain cutoff frequency fT, maximum oscillation frequency fmax and reduce the series resistance of the drain to source compared with the HEMT without GaN cap layer. The large Ids of the HEMT with cap layer is attributed to the increase of the concentration of two dimensional electron gas (2DEG). Moreover, the change of the doping concentration of the cap layer will affect the gm and Ids.
Piezoelectric Properties of 1-3 Piezoelectric Tubular Composites
Authors: Ma Yu Ting , Zhong Jun , Zhang Li , Wu Yun Liang
Published: November 2012

The piezoelectric coefficients of 1-3 piezoelectric tubular composites are studied. Taking into account the non-uniform electric field distribution in piezoelectric tube, the piezoelectric coefficients as functions of volume fraction, aspect ratio, tube density and matrix materials were discussed. By means of finite element software, the relationship between piezoelectric coefficients and ceramic volume fraction was derived to validate theoretical results. This research provides theoretical guidance and basis for the design of 1-3 piezoelectric tubular composites.
Experimental Study on Friction Damping Characteristics of Metallic Materials with Non-Conforming Contact
Authors: Wu Jun , Zhang Ming Hui , Zhang Di , Xie Yong Hui
Published: November 2012

A rig was built to study the friction damping characteristics of metallic materials with non-conforming contact. The hysteresis curves which show the relationship between the tangential force and relative displacement of the contact between a spherical surface and a flat surface were measured. The effects of the vibration amplitude on the friction damping characteristics of the contact were investigated. The results show that both the amplitude of friction force and the friction coefficient increase as the vibration amplitude increases at first and then reach to a constant value. The equivalent stiffness decreases as the vibration amplitude increases, while the equivalent damping increases at first and then decreases slowly. And both of them trend to constants when the vibration amplitude is larger than 4.8μm.
Study on Mathematical Model of Radial Runout Error
Authors: Chen Li Jie , Zou Ping
Published: November 2012

According to the standard definition of radial circular error, set up any space surface radial runout errors of least squares mathematics model. The coordinate origin of the model can be freely selected, nor equal angle interval among discrete sampling points. Analysis by computer simulation, results show that the model developed is right and pratical. On the basis of mathematical models, using four direct algorithm for unconstrained optimization, radial runout errors can be evaluated in accordance with the minimum conditions. Mathematical models can be used for three-coordinate measuring machine and also available for other intelligent instrument for measuring parts of the radial runout errors.
Analysis of Dimensional Accuracy of Spun Parts by Taguchi Approach
Authors: Šugár Peter , Šugárová Jana , Morovič Ladislav , Zemko Peter
Published: November 2012

The paper brings the results of wall thickness distribution analysis of formed part produced by CNC multi-pass conventional metal spinning. The thickness reduction was measured by optical 3D scanning method and the influence of the feed, workpiece geometry and planar anisotropy of the blank on the wall thickness reduction was studied. For experiment design, an orthogonal array L27 was used and ANOVA (Analysis of Variance) was carried out. Based on the results it is determined that the highest reduction of wall thickness is observed in the conical part of the experimental sample. Workpiece geometry is the most important factor which influences the wall thickness variation.
Evaluation of Residual Stresses in Butt-Welded Joints by Residual Magnetic Field Measurements
Authors: Liang Bin , Gong Jian Ming , Wang Hai Tao , Ye Cheng
Published: November 2012

Measuring residual stray field (RMF) signals provides a promising tool to analyze the stress in ferromagnetic welded materials. In this paper, the variations of the normal component of the RMF, Hp(y), perpendicular to welded seam are measured. The finite element method is used to model residual stress in the specimen. The influence of residual stress on the Hp(y) component is shown. It is found that the distributions of the Hp(y) component are described by a Boltzmann fitting curve, show a good qualitative correlation with residual stress. A quantitative method for the evaluation of residual stress in ferromagnetic steels based on the gradient of the Hp(y) component and equivalent (vonMises) stress is presented.
Parametric Analysis of Shear Behavior of Concrete Beams Reinforced with Continuous FRP Rectangular Spirals
Authors: Li Ying Tao , Jiang Shi Yong , Li Bing Hong , Shi Qian Hua , Hu Xian Qi
Published: November 2012

An experimental program was carried out by the author to investigate the shear behavior of concrete beams reinforced with continuous FRP rectangular spirals, the main variables considered in the test were the shear reinforcement ratio and the shear span to depth ratio and the longitudinal reinforcement ratio. However, the experimental program is inadequate to gain insight into the shear behavior of the members. First, the quantities of test specimens were too small, only six beams were made and tested, the experimental database was so limited that the resultant analytical results and conclusions may not be sound enough. Second, not all the main factors that have influences on the shear behavior of the members have been treated as variables in the experimental program, such as the effective transverse compression stress and the concrete compression strength, the influences of these two factor on the shear behavior of the members were not clear yet through the experimental study. Considering the insufficient information provided by the experimental investigation, the parametric analysis of the shear behavior of the members was carried out, and a revised rotating-angle softened truss model for the shear analysis of the members was proposed as the analytical tool. Based on the proposed model, the influences of various factors on the shear capacity and shear failure modes of the members were discussed, related nonlinear analysis was carried out using the arithmetic of iteration and step approximation, and several FORTRAN codes were written accordingly. Through the experimental study and the parametric analysis, it is indicated that the shear capacity and the shear failure modes of the members are greatly influenced by three major factors, including the shear reinforcement ratio and the shear span to depth ratio and the effective transverse compression stress. The influences of the concrete compression strength and the longitudinal reinforcement ratio on the shear capacity are not noticeable comparatively. The shear capacity is little affected by the shear span to depth ratio in the case of the shear-tension failure, there is no noticeable correlation between longitudinal reinforcement ratio and the shear failure modes.
Influence of the Metal Sheet Parameters on the Results of the Erichsen Test
Authors: Gillo Giuliano
Published: November 2012

Considering an isotropic rheological law of the sheet material and the power law relationship between the stress and the plastic strain, the present paper by using the finite element method analyzes the influence of the material parameters on the results of the Erichsen test in terms of force-displacement curve of the punch and the normalized thickness measured at the specimen apex also varying the coefficient of the Coulomb friction law. Moreover for an AA5083 aluminum alloy the results of the numerical simulation of the Erichsen test will be compared to those obtained experimentally.
Production of Nano NiO Particle with Chemical Precipitation Method and their Characteristics
Authors: Zhang Cun Lai , Shao Zhong Bao
Published: November 2012

Nano nickel oxide (NiO) particles were synthesized by a homogeneous precipitation method using NiCl2 as starting material and CO(NH2)2 as precipitant. Proper amount of NP-10 and appropriate organic solvent were added in the preparation process as dispersant. The chemical composition and properties were characterized by means of transmission electron microscope, X-ray diffractometer, and thermo gravimetry-differential thermal analyzer. The effects of reactant ratio, reaction temperature, reaction time, surfactant concentration, organic modifier concentration, agglomeration temperature as well as other reaction conditions on the appearances, size and dispersity degree of nano particles were investigated. The experiment results show that homogenous nano NiO particles were obtained by reacting nickel oxide and urea with a weight ration of 1:5 for 6 h at 80°C, then calcining for 2 h at 300°C. Adding surfactant NP-10 and organic solvent butanol to reaction system increases the dispersity and decreases the particle size of nano nickel oxide.
Induction Heating Furnace Temperature Control Based on the Fuzzy PID
Authors: Hou Xue Gang , Wang Cheng Long
Published: November 2012

Induction heating furnace temperature control is a complex nonlinear hysteretic inertial process, it's difficult to obtain an accurate mathematical model because the temperature and disturb from outside is complicated. The normal PID control algorithm is hard to satisfy the standards of control. The fuzzy PID controller provided in this article is a combination between fuzzy control and the traditional PID control. The Fuzzy control theory is used to setting the ratio, the integral and the differential coefficient of the PID control. In the run-up stage, rapidity is guaranteed, overstrike and the steady-state error is up to the mustard. An example indicates that fuzzy PID control is superior to the normal PID controller.
Thermal Design and Thermal Analysis of Control Cabinet for Pattern Sewing Machine
Authors: Li Qi Bing , Huang Yu
Published: November 2012

Thermal design and thermal analysis of control cabinet for pattern sewing machine was researched to make components’ temperature meets the requirement. Basic flow sheet of research process was introduced. Then, preliminary thermal design and thermal analysis was performed, and the computed result indicated that temperature of some components was out of limit. Next, by optimizing the location of fan and components in cabinet, the temperature of servo driver 1 to 3 dropped 11.1 oC, 10.8 oC and 11.3 oC respectively. The data shows that cabinet’s heat dissipation is improved, and the thermal design of the cabinet is reasonable. Finally, Thermal test of the prototype was performed, which proves the thermal design is effective, and the numerical simulation result is correct.
Investigation on Numerical Calculation of Thermal Boundary Resistance between Superconducting Magnets
Authors: Du Hu , Wu Gang , Li Xiang , Bi Ke , Ma Ji , Wang Hui Ling
Published: November 2012

Aiming at the problem that thermal boundary resistance (TBR) has an effect on heat transportation of superconducting magnet when Superconducting Magnetic Energy Storage (SMES) is cooled directly, from perspective of numerical calculation, truncated cone, circular arc and triangular models are used to simulate the solid to solid contact surface, and finite element method is adopted to carry on numerical simulation calculation for thermal boundary resistance. With comparison and analysis of the calculation results of the three models, knowing that the value calculated with the triangular model when its control angle is 30° is close to the measured value and its relative error is 17%. Meanwhile, the error source is analyzed. This dissertation can be a good reference to the research on superconducting magnet heat transportation.
Thermal Analysis and Research of Multi-Chip Component Substrate Based on Different Thermal Conductivity Models
Authors: Zang Ming Xiang , Luo Pei , Xiao Yuan Ming , Jiang Jian Guo
Published: November 2012

With the development of electronic packaging technology, the time criterion and the space criterion of heat transfer have been becoming smaller and smaller, which results in the stronger Non-Fourier effect．Using the classical Fourier model to analyze the heat transfer of the substrate will inevitably make the result deviate from the actual conditions greatly. However, using the Non-Fourier model could closely describe the real situation. This paper regards the Fourier model and the Non-Fourier model separately, sets up their own mathematics-physics equations to the heat-transfer model of three-dimension multi-chip module(MCM) substrate，adopts finite difference method(FDM) to solve the corresponding equations，and get the temperature field of the three-dimensional substrate model. To test the accuracy of the results, meanwhile, the thermal analysis software ANSYS ICEPAK is used to calculate the same model. The results indicate that，compared with the classical Fourier model，the results of Non-Fourier model have great advantages：the temperature value is higher, the time is longer for temperature field to enter the stable state, changing of the temperature is faster and the phenomenon of thermal coupling is stronger too.
Design and Fabrication of Micro-Variable Radiator
Authors: Cao Sheng Zhu , Chen Xue Kang , Wang Xi Yuan , Han Chuang , Yang Jian Ping
Published: November 2012

Micro-variable Radiator with its small volume, light weight and less power consumption quite meets the requirement of Micro/Nano satellite thermal control. Prototypes fabricated by bulk silicon technology have poor thermal performance owing to their confines of material and process. In this paper, a novel micro-radiator based on laser micro processing technology and polymer material was proposed, its operational principle was introduced and the relationship between structural and thermal performance was analyzed theoretically. A prototype was fabricated by UV laser micro-processing, dip-coating and magnetron sputtering technologies. Test results show that the actuation voltage is 97V and variation of radiation power is about 0.1W.
A Case of Structural Integrity of Ageing Fighter Aircraft Leveraging on Condition Maintenance Methodology
Authors: Younus Bilal , Farooq Bilal , Jamal Ahmed , Manarvi Irfan Anjum
Published: November 2012

In recent years aircraft maintenance practices have been influenced by changes in aircraft design philosophy and improvements in engineering technology. Advances in manufacturing techniques and material specifications have made it less necessary to carry out frequent disassembly of aircraft and components to establish confidence. The need to be competitive and to reduce costs has meant that the aviation industry has sought to gain advantage from these improvements by moving from time consuming and cost extensive, invasive maintenance to a philosophy of on condition maintenance (OCM). The research is aimed at highlighting an OCM based maintenance methodology by carrying out an extensive study on structural integrity of various vintage Chinese fighter aircraft. The study finds that the structure of Chinese fighter aircraft is robust and is capable of flying for more hours/years than specified by OEM. The study will help air forces operating the ageing Chinese fighter aircraft in extending the lives of their respective fleets well beyond the OEM prescribed limits.
Propagation Characteristic in 2D Phononic Crystals with Bending Linear Defect
Authors: Fan Guang Hui , Zhao De Xun , He Jiao , Liu Ying Kai
Published: November 2012

The band gap of 2D perfect and defect phononic crystal are calculated by using plane-wave expansion (PWE) and supercell plane wave method, which is consist of Al2O3 embedded in the epoxy resin with a square arrangement. Compared to the perfect, the gap of defect will become wider. As the size of defect length ld varied, the band structure changed. It is found that the acoustic wave only propagates along the path of defect when the propagation of acoustic wave is simulated on the 900 bending defect phononic crystals by matlab. It means that the waves are localized. So the defect mode of phononic crystal can be used as acoustic waveguide along the specific path.
On-Line Detection Distribution Strategy Research of Complex Surface Based on Bayesian Networks
Authors: Yan Li Wen , He Qi Bao
Published: November 2012

Studying how to distribute the sampling points on processing surface has important practical significance on improving the detection quality and efficiency. So, this paper introduced Bayesian networks to the research of sampling points reasonable distribution, carried out Bayesian networks classifier learning of four typical sampling methods and the result obtained through analysis experimental and simulation data verify the feasibility of this method.
Transformer Fault Diagnosis of Rough-Neural Network Based on MEA
Authors: Gao Jin Lan
Published: November 2012

Combining mind evolutionary algorithm with rough set and neural network, this paper proposed a rough set neural network based on MEA for transformer fault diagnosis. Rough set attribute reduction as the front-processor of neural network diagnostic device, and using MEA to search rough set discrete breakpoints and optimize neural network weights and thresholds, it avoided complex manual trial of the conventional rough set attribute reduction and slow convergence speed and low precision of BP neural network, then faster convergence to the global optimum solution and improves the diagnosis speed and accuracy. Simulation results show that this method is effective.
Concurrent Tolerancing Design Based on Time Value of Manufacture-Quality Loss Cost
Authors: Jin Qiu , Liu Shao Gang
Published: November 2012

The traditional manufacturing cost-tolerance function is improved from the point of view of the time value of money, and this makes manufacturing cost in tolerances design more actual. A comprehensive mathematic model is constructed for the concurrent tolerance optimal design based on the time value of manufacture-quality loss cost. Purpose of the establishment of the model is equivalent calculation for cost-tolerance function and quality loss function of different time points, so as to make them calculated in the same time point, and concurrent tolerance optimal design is achieved. This modified model’s validity is proven by an illustrative example.
Survey and Analyze the Line Output Characteristics in Inkjet Printing
Authors: Cui Xiao Meng , Chen Guang Xue , Wang Huan Mei
Published: November 2012

Inkjet characters and graphics quality are impacted by rough and wavy exterior appearing along the line edge caused by feather and penetration phenomena. In order to deliberate whether only positive line attributes measurement was adequate to detect the output characteristic of an inkjet printing system, negative line quality survey was involved in. The attributes such as line width, contrast and blurriness etc. of negative lines in vertical and horizon direction together with positive lines were measured and analyzed though comparison according to ISO 13660 standard. Output characteristics of all kinds of lines were further summarized and detected in terms of attribute correlations of positive lines presented in existing study. Results show that when negative and positive lines are considered altogether the correlations among lines in different direction turn complex, which are distinguished with the simple correlativity in positive line quality detection.
Polyethersulfone Composites Reinforced by Silica Nanoparticles
Authors: Ou Cheng Fang
Published: November 2012

Three series of PES/SiO2 composites, containing 0.5-7 wt% nano-sized SiO2 with different specific surface area, were prepared by solution blending. The resulting composites exhibit the higher glass transition temperature (Tg) than that of pure PES. The Tg of composite showed a maximum increment of 24.0 °C by the addition of 7 wt% A300. The trade name of A300 is Aerosil 300. It is one of the fumed silica nanoparticles products of Degussa. The decomposition temperatures (Td) of composites were always higher than that of pure PES and showed a maximum increment of 37.0 °C by the addition of 3 wt% A300. The oxygen transmission rate of composites are always lower than that of pure PES and decreases with increasing SiO2 content to 1 wt% and then increases to 7 wt%. The composite with 1 wt% A300 exhibits a maximum decrement percentage of 46 %. The Tg, Td, and oxygen barrier property are as a function of the SiO2 content and size. The finer SiO2 are more effective in increasing the Tg, Td and oxygen barrier property.
The Study of Fault-Diagnosis Method of Reciprocating Compressor Based on Fuzzy Fault Tree Theory
Authors: Gong Jian Chun , Tian Peng Fei
Published: November 2012

Since working condition of reciprocating compressor is awfully bad and it has bigger risk in operation and higher fault rate，it is of importance to study reciprocating compressor fault. Fault tree has been established in this paper by analyzing factors leading reciprocating compressor fault based on the method of fault tree. 21 minimum cut sets leading to reciprocating compressor fault can be gotten through qualitative analyses on this fault tree，the happening probability of the top event can be calculated and the importance of the basic event s can be analyzed through quantitative analysis. The expert inquiry method combined with fuzzy sets theory is adopted to assess the happening probability of the basic events and top events.
Noise Character of Cooling Tower and Control Discussion
Authors: Liu Huan , Chen Chang Zheng , Zhou Hao
Published: November 2012

This article takes the noise control of a cooling tower for a residence area as an example. On the base of measuring data, the noise resource is analyzed and the character of the noise resource is discussed. In the aspects of sound elimination, sound absorption and sound insulation, a set of practical controlling measures are elaborated. The result shows that the effect of noise reduction in this scheme is evident, and in the meantime the wind volume and temperature for the equipment are satisfying as well. Perfect effects of noise reduction can be obtained in the working project.
Adaptive Interpolation of Tool Posture Vector in Five-Axis Flank Milling
Authors: Tian Jun Feng , Lin Hu , Yao Zhuang , Li Jie , Yu Jin Gang , Li Qing
Published: November 2012

Five-axis flank milling is an important machining technique, especially in machining of complex parts. Tool posture vector can change easily using two axes of rotation to achieve optimum cutting conditions. However, the tool posture vector may change beyond the interpolation plane. This will result in overcut or undercut. In this paper, an adaptive interpolation algorithm of tool posture vector is proposed. In the proposed algorithm, the commanded feedrate for linear axis is kept constant for most time and adaptively adjusted to confine the chord error within a specified tolerance range during the interpolation process. The tool posture vector changes in the interpolation plane with a constant rotation degree. Simulation results from example are provided to verify the feasibility and advantages of the proposed scheme.
Improved Atomic Force Microscopic Inspection Process of Liquid Crystal Display
Authors: Jiang Jui Chin , Lin Tai Ying
Published: November 2012

The Define, Measure, Analyze, Improve, Control (DMAIC) Six Sigma strategy was designed to improve product quality and to reduce product defects. Because of its classification and feature selection capabilities, the Mahalanobis-Taguchi System is integrated in the improvement stage of DMAIC to reduce redundant testing items in the testing procedure and to optimize the economic benefit of the test flow. The important variables screened by the Reduced Model in MTS are C2, C5 and the classification accuracy rate is 99.13%. Implementation results show that atomic force microscope (AFM) inspection process reduces inspection attributes and maintains high inspection accuracy. The average AFM thickness is decreased from to . The standard deviation is reduced from 45.76 to 8.73, PCI is raised from 0.73 to 3.81, process accuracy is improved from 0.07 to 0.012, and process performance is improved from 0.67 to 3.76. Finally, this study confirmed that the new process parameters can reduce variance in the alignment membrane thickness and enhance the overall LCD chromaticity yield.
Improvement Effect of Functionalized Cnts on Mechanical and Thermal Properties of Epoxy Matrix
Authors: Zhang Wen Jing , Li Xiao Yan , Wang Xia , Yu Deng Guang , Qian Wen Hui , Ye Yi Ting , Wang Zi Yu
Published: November 2012

Targeting at the brittleness of cured epoxy (EP), functionalized CNTs were integrated into the thermoset to make high-performance CNTs/EP nano-composites.In this investigation, polymaleic acid modified CNTs with a high surface grafting ratio (PMA-CNTs)was prepared through the plasma induced grafting technique , then further functionalized with amino groups to yield A-PMA-CNTs, which were then incorporated into epoxy matrix. Characterization of mechanical properties and heat resistance of the A-PMA-CNTs/EP nanocomposites indicates that A-PMA-CNTs can significantly strengthen and toughen the epoxy resin, with an increased glass transition temperature.
Application Study on Automatic Particle Count Technology Used in Fuel Filtration Efficiency Test
Authors: Chen Hong Yan , Xu Zhang Hong , Ye Nan Hai
Published: November 2012

Automatic particle counter is widely used in particle size analysis, fluid particle pollution degree and filtering properties testing. In this article, the test-bed of Zhejiang Universe Filter Product Qulity Test Center used in fuel filtration efficiency test is introduced. According to the domestic and foreign relevant test standard, this test-bed adopts particle counting and multi-pass method for experimenting of international general approval. And by using the test-bed, we can manage to test and analyse filtration efficiency and dust holding capacity of automotive fule filter.
Multiaperture Connection Method for Three-Dimensional Mesasurement Based on Quaternion
Authors: Zheng Peng , Zhang Lin Na , Zhao Feng Xia
Published: November 2012

A novel multiaperture connection method for three-dimensional shape measurement is presented. The principle of multiaperture method is to obtain subapertures relative location and orientation by measuring the object from different subapertures, and afterwards connecting them together. Rrotation and transformation of subapertures are the key problems to realize multiaperture connection. In order to improve calculability and efficiency of the connection algorithm, a new connection method using quaternion is proposed. The mathematic model of multiaperture connection associated with our proposed method is discussed, and the experimental measurement on the basis of digital grating projection system is carried out to demonstrate the validity of this suggested method. Compared with the conventional connection method, this method offers with such advantages as computational simplicity, high efficiency and reasonable accuracy.
Application of FastICA Algorithm in Wind Turbine Condition Monitoring
Authors: Shan Guang Kun , Zhang Hai Long , Wang Xiao Dong , Liu Ying Ming
Published: November 2012

In wind turbine condition monitoring, the sensors often can not be installed to the ideal position. Compare the common signal processing method comprehensively and give the advantage of the fastICA algorithm in the wind turbine condition monitoring. Give the basic principle and mathematical model of the fastICA algorithm, while monitor and analysis the wind turbine state data based on the fastICA algorithm. The results show that this algorithm can separate the vibration characteristics of the tested compenent of the wind turbine from the vibration signals quickly and accurately.
Effects of Deformation Ratio above Recrystallizaton Temperature on Microstructure and Properties of 2A12 Aluminum Alloy
Authors: Zhang Shi Xing , Zhu Yu Ping , Cai Gang Yi
Published: November 2012

The thermomechanical treatment of a 2A12 aluminum alloy was researched and the influence of deformation ratio above recrystallization temperature on microstructure and hardness was analyzed emphatically. The result reveals that when the deformation ratio is low at first, the hardness of specimen decreased because the effect of recrystallization softening overwhelms the effect of deformation strengthening. However, hardness increased with increasing deformation ratio. In addition, the microstructure became more homogeneous and grains were refined obviously by metallography microscope observation with increasing deformation ratio. The second phase precipitates dispersedly to strengthen the alloy.
Effects of B2O3 Flux on the Synthesis and Microstructure of Aluminum Metal Matrix Composites
Authors: Wang Hong Ming , Li Gui Rong , Yuan Xue Ting , Zhang Xun Yin , Zhao Yu Tao , Wang Jun Jie , Gu Kai Xuan , Zhang Hong , Xu Xiao Jing
Published: November 2012

new flux method is explored to decrease the reactive temperature of in situ chemical reaction to fabricate particles reinforced aluminum matrix composites. When B2O3 flux is added into the mixed reactive salts the melting points of them decrease with the increase of adding amount of B2O3 in the range of 1-5wt.%. When w(B2O3)=5% the melting point of K2TiF6-B2O3 salt is 450°C,which is decreased by 90°C compared with that of pure K2TiF6. Meanwhile the in situ reactive time is shortened and the actual volume fraction is increased.
Coupled Simulation on Temperature Field and Microstructure Formation Process of K4169 Superalloy Blade in Investment Casting
Authors: Liu Han Wu , Ren Hong De , Dong De Chao
Published: November 2012

In order to control the grain structure of K4169 superalloy blade which affects its mechanical performance and ability of resistance to corroding in high temperature state, the transient temperature field distributions were analyzed by using equivalent thermal entropy method with the consideration of the practical boundary conditions, such as, heat exchange and heat radiation in solidification, and the relationships between temperature and time of every point on vertical section and cross section during phase change heat transference process of K4169 superalloy were obtained. The changes of solid phase fraction after every time step were calculated basing on the model of equiaxed dendrite growth solute diffusion put forward by Rappaz and other persons. we used the data to modify the temperature in the same step when phase change latent heat was released. The Cell Automaton technology was adopted to coupled simulate the grain structure formation process of K4169 superalloy blade with its temperature fields using continuous nucleation model and kinetic model of dendrite tip growth. These simulation results which coincided much well with the ones of experiment test have played a very important role in studying superalloy mechanical performance and ability of resistance to corroding of K4169 alloy blades.
Effect of Divorced Eutectic on the Liquation Crack Susceptibility of Al-Cu Alloy
Authors: Yang Cheng Gang , Zhen Qiang , Xin Ji Jun
Published: November 2012

Hot ductility testing is used to evaluate the liquation cracking susceptibility of high Strength aluminum alloy 2219, the fracture surface of hot ductility samples are inspected by SEM, the results showed that the melting point of α(Al)-CuAl2 divorced eutectic is higher than that of α(Al)- CuAl2 eutectic. The α(Al)- CuAl2 divorced eutectic is prior to melting during heating process and solidification during cooling process, so the BTR of Al-Cu alloy 2219 is narrow. The low liquation cracking susceptible and good weldability of Al-Cu alloy 2219 due to the rapidly recover the strength and ductility in elevated temperature which caused by the α(Al)-CuAl2 divorced eutectic solidification during cooling process.
Reaction Hot-Pressed Sintering of Grain-Refined TiB2-TiC Composites by AlN-SiC Solid Solution
Authors: Wang Xin Yu , Xia Long , Song Liang , Liu Qing Tian , Wen Guang Wu
Published: November 2012

Grain-refined TiB2-TiCx composites were designed and fabricated by reaction hot pressing under 30 MPa at 1800 °C choosing 4.8 Ti-B4C material system with Al, C and Si3N4 as additives. The microstructure of the resultant was homogeneously grain-refined TiB2-TiCx matrix reinforced by AlN-SiC solid solution particles that were embedding tiny TiB2-TiCx crystals. The obtained specimen showed relative high flexural strength of 860±30 MPa and fracture toughness of 13.6±0.3 MPa·m1/2, which can be explained by several toughening mechanisms.
Influences of Ultrasonic Wave on Polycrystalline Alumina Fibers Synthesized
Authors: Zhang Yong Zhi , Li Hong Xia , Wang Jin Xiang
Published: November 2012

In order to improve the stabilities of A95-aluminum-silicon sols, the influences of various ultrasonic field, ultrasonic time and ultrasonic frequency on the property of aluminum-silicon sols were researched. The physical-chemical performances of sols, such as the sol viscosity, rheological properties and microstructure, and so on, were measured. The results show that the influence of sonochemical actions on the stability of the Al2O3-SiO2 sol is remarkable. Standing wave fields accelerate the molecules agglomeration of the sol. In the diffusion wave fields, the stability of the sol increases with ultrasonic frequency enhances, but the stability first increases and then reduces with the extension of ultrasonic time. When ultrasonic frequency and ultrasonic time is 100 Hz and 60 minutes respectively, the stability of the Al2O3-SiO2 sol is the best.
Research on Synthesizing Process under Ultrasound Coupling and Refining Performance of Al-Ti-C Grain Refiner
Authors: Li Ying Long , Cao Fu Rong , Jin Li
Published: November 2012

The microstructural characters and refining property of Al-Ti-C grain refinement alloy prepared by ultrasound coupling method were studied by analytical means such as SEM, and the reaction synthesis mechanism of Al-Ti-C grain refinement was discussed. Experimental results show that the Al-Ti-C alloy refiner using “thermite reduction method” under high-energy ultrasound was prepared experimentally. Its microstructure character is that master alloy has smaller size of TiC, its quantities are larger and are dispersed. Melt reaction is generally that the source of titanium releases Ti atoms under high temperature of ultrasonic. Ti atoms react with aluminum to generate TiAl3, and react with carbon to generate TiC.
Effect of Alloying Elements on Microstructure, Texture Development, and Mechanical Properties of Magnesium Alloys
Authors: Ha Chang Wan , Choi Sung Ji , Park No Jin
Published: November 2012

In this study, the magnesium alloys AZ31, ZK10, and ZEK100 are investigated through microstructure, texture, and tensile test. The sheets were hot rolled, and different results were found for different chemical compositions. The contained elements affected the grain size, shear band, twins, and intensity of the basal texture of the magnesium alloy. Thus, if a magnesium sheet had finer grains and a weak (00.1) texture because of its chemical composition, it had the most favorable formability.
Research on Cold-Rolled Bimetal of High-Tin Aluminum Alloy and Steel
Authors: Cui Guo Ming , Li Xing Xia , Zeng Jian Min
Published: November 2012

Bimetal of high-tin aluminum alloy and steel was fabricated by cold-rolling process; microstructure, bonding strength and bonding mechanism for bonding interface of the bimetal were investigated under cold-rolling and recrystallization annealing state, respectively. Experimental results indicate that tin phase of bimetal in cold-rolling state shows a belt type distribution, however, it, in recrystallization annealing state, is uniformly distributed just like some “isolated islands”. A well bonding interface, between layers of high–tin aluminum alloy and pure aluminum, can be obtained, and it is difficult to distinguish one layer from the other; but the interface, between layers of low-carbon steel back and pure aluminum, is clear and uneven. And meanwhile, bonding mechanism of bimetal interface, in cold-rolling state, is cold pressure welding and mechanical occluding, But it, in recrystallization annealing state, is cold pressure welding, mechanical occluding, and metallurgic bonding. After recrystallization annealing, at 350°C for 2h,the bonding strength of bimetal approaches to 92.4MPa, which is about 26% higher than that of cold-rolling state.
The Study on the Precipitation Behavior of the Second Phase Particles for Fine Grain and High Strength IF Steel
Authors: Zhang Hong Mei , Qiao Li Feng , Liu Qin Bo
Published: November 2012

The new type SFG HSS (super fine grain, high strength steel sheet) has been developed by adding solid-solution strengthening elements to conventional IF steel such as Si, Mn. The precipitation behavior of the second phase particles was observed and studied by a carbon extraction replica technique used transmission electron microscopy (TEM). The shape of the small second particles is similar to spherical and ellipse, the sizes of which are 10~30nm. It is seen that the particles are dispersed on the matrix. The precipitate composition of small particles is Nb (CN) and the precipitate composition of large particles is NbC examined by energy dispersive X-ray (EDX). It is noted that the yield strength is low as well as the tensile strength is high by the PFZ which is free of precipitate called precipitated free zone on the one side of the grain boundary. The results of microstructure shows that the second phase particles pinned on grain boundary not only can inhibit the grain growth, but also the grain can be fined.
Microstructure Evolution of Dynamic Recrystallization of 42CrMo Steel during Multi-Stage Forging by FEM
Authors: Yang Dong , Chen Wen Lin , Zhou Rui , Wang Shao Yang , Ma Yong , Zan Xiang , Peng Li Jing
Published: November 2012

Different process steps of the workpiece have different effects on the microstructure in the multi-stage forging. In this study, the effect of four different process steps of steering arm on microstructure was studied by FEM. Results have showed that upsetting is beneficial to refine the microstructure as well as finish forging. Especially drawing can make the distribution of microstructure homogeneous while bending has less effect on it. The already-designed forging process for steering arm was reasonable based on the simulation. Eventually, the grain size level of the steering arm was tested as 6.5 based on the conventional standard.
Study on Utilization Technology of Vanadium Titanium Magnetite Based on the Rotary Hearth Furnace Direct Reduction Process
Authors: Liu Gong Guo
Published: November 2012

Through carrying out large scale of experiments, the process of ‘rotary harth furnace direct reduction—deep reduction electric arc furnace—extracting vanadium from vanadium bearing slag—extracting titanium from titanium bearing slag gets through and the recovery of Fe, V and Ti reached 90.77%, 43.82% and 72.65% respectively. With the study on the laboratory experiments and industrial tests, the bottlenecks of this technology such as low metallization rate of vanadium-titanium magnetite in direct reduction process, low reduction rate of vanadium in EAF, vanadium-recovery of hot metal with high silicon content, titanium-recovery of high –Mg &Al slag with titanium, and so on, have been solved. Based on this, the metallization rate of vanadium-titanium magnetite in direct reduction process is more than 90%, reduction rate of vanadium in EAF deep reduction process is more than 80%, vanadium-recovery rate in slag is more than 65%, and titanium-recovery rate in slag is more than 75%. That means good study results have been gotten. Furthermore, low-carbon pig iron with good quality in EAF steelmaking are gotten. Otherwise, V2O5 sheet and titanium products can meet the requirements of GB3283-87 and PTA121, respectively.
The Application of the High Alumina Composite Slag in Semi-Steelmaking
Authors: Chen Yong , Liang Xin Teng , Zeng Jian Hua , Li Gui Jun , Yang Sen Xiang
Published: November 2012

In order to promote the fusion of lime in semi-steelmaking, fluorite was used in converter steelmaking to improve the melting slag ratio, while fluorite is very harmful. In order to make best use of the metallurgical slag and improve the scorification problems in semi-steelmaking, PANGGANG Research Institute developed a new type high alumina composite slag, and accomplished industrial application which also achieved good results. They found that this new type slag can improve the melting slag ratio greatly and decrease the times of “re-drying” and “slopping” throughout the converter steelmaking, the slag sate can be good controlled, at the same time the content radio of TFe decreased significantly.
Ultrasound-Assisted Electrospark Deposition of 3Cr2NiMo Steel
Authors: Qi Jun
Published: November 2012

Ultrasound-assisted electrospark deposition (UAESD) is an electrospark deposition (ESD) technology combined with ultrasonic vibration. In this paper, the effect of main process parameters, including discharge voltage, discharge frequency and specific deposition time, on depositing thickness and strength for 3Cr2NiMo die steel are experimentally studied and compared between the UAESD and the ESD process. The results show that the depositing thickness decreases between 28% and 53% while the depositing strength increases under the influence of the ultrasonic vibration.
A Study on Recrystallization Behavior of Low Carbon Bainitic Steel during Multi-Pass Deformation
Authors: Guan Yun , Chen Qing Feng , Ma Jia Yan , Deng Zhao Jun
Published: November 2012

The multi-pass compression deformation of low carbon bainitie steel was carried out on a thermal simulator between a temperature range of 1050~800°Cwith accumulated 60.7% deformation and a deformation rate of 2s-1. The recrystallization behavior of the tested steel during high temperature deformation was discussed after comparatively analyzing the stress-stain curves and austenite deformation structures under different deformation conditions. The results show that with the same strain rate and total deformation, the grain size of recrystallized austenite is mainly determined by pass temperature and pass deformation, especially the latter, while has little relation with quantity of pass. The ultimate deformation stress is determined by ultimate deformation temperature and improved by the increasing quantity of pass.