bluuebunny/crossref_metadata_2025 huggingface dataset:
Femtosecond Laser Micromachining of High Quality Groove on Sapphire Surface
Authors: Qi Li Tao , Hu Jin Ping
Published: November 2012

In this paper, high quality grooves were fabricated by femtosecond laser pulse on sapphire surface. Grooves were fabricated under different experimental conditions. The lateral and vertical machining precision was evaluated by scanning electron microscopy and profilometer. High quality grooves could be obtained at the condition of low pulse energy, high scanning-speed and increasing the number of laser scans. The relationship between the width and depth of the groove and the key parameters of femtosecond laser micromachining system was studied. Several samples of the high quality grooves were obtained by femtosecond laser pulses. High quality grooves have a potential application of the fabrication of sapphire-based devices.
Low-Temperature Polycrystalline Silicon Thin-Film Transistors Enhanced by Diode-Pumped Solid State Green Continuous-Wave Laser
Authors: Wang Jyh Liang , Tsai Chun Chien , Hwang Chuan Chou , Hsieh Tsang Yen
Published: November 2012

A novel diode-pumped solid-state continuous-wave (CW) laser technology has been demonstrated for high-performance low-temperature polycrystalline silicon thin-film transistors (TFTs) fabrication. The CW laser-crystallized (CWC) poly-Si thin films indicated the excellent crystallinity with the flat surface morphology at grain boundary. Besides, the CW laser activation is a low-thermal budget process and can achieve the lower sheet resistance of 50 Ω/□ and uniformly redistributed dopant profiles. The n-channel CWC TFTs revealed the superior field-effect mobility reaching 505 cm2/V-s and the lower subthreshold swing as compared with the conventional excimer laser-crystallized ones.
Research of Fiber Laser Cladding Technology on Shaft-Parts
Authors: Miao Hong Bin , Zhao Wen Qiang
Published: November 2012

The principle and features of laser cladding technology was described, and the fiber laser equipment was introduced. Coat an alloy wear-resistant layer on the failure surface of mine hydraulic prop, motor rotor, shovel drum and other shaft-parts by using fiber laser cladding technology, and take mine hydraulic prop as an example to introduce the steps of the fiber laser cladding. The results show that the fiber laser cladding repair technology can significantly improve the quality, hardness, wear resistance, service life of shaft-parts surface.
Laser Instant Shaping of Surface Microstructure Based on Function
Authors: Wang Ling , Li Nian Lian , Jiang Su Qin , Li Bo Kui
Published: November 2012

Based on the functions of good surface bearing, lubricating and wear-resisting properties, this paper designs several microstructures including tangent ring, separated annular slot, positive direction reticular slot, etc. Microstructure is shaped by laser carving method, and contrastively analyzed compared with 3-D bearing curve and related parameters of ideal functional surface. The results demonstrate that functions of surface can be met by certain designed and processed shapes. Laser carving is a fast and convenient surface microstructure shaping method, in which as texture surface of separated annular slot, the shape of 3-D bearing curve stands to reason, and relevant parameter values and surface performances are good and obvious respectively.
Effect of Laser Irradiation Parameters on Healing Fatigue Damage for Polycrystalline Copper Film
Authors: Nai Chang Gang , Shang De Guang , Ren Chong Gang , Wang Lu , Liu Xiao Dong , Chen Hong , Chen Tao
Published: November 2012

In this paper, the effect of laser parameters on fatigue life was investigated by laser irradiation for the undamaged and pre-damaged copper film specimens with thickness of 25μm. The results showed that the laser parameters have a great impact on the strengthening of original specimens and the healing of specimens with fatigue damage, and total fatigue life of the healed specimen with fatigue damage was longer than that of the strengthened original specimen. According to the obtained fatigue life results under different laser irradiation conditions, the optimal laser parameters were identified. The fracture morphology was observed by SEM. The results showed that, under the optimal laser parameters condition, a dense layer was found on the surface of specimen and the columnar grains were refined, which results in increasing the total fatigue life of the specimen.
Mechanical Analyze of Casing Failure with Sand Production in Loose Sandstone Reservoir
Authors: Zhai Xiao Peng , Lou Yi Shan , He Bao Sheng , Ji Hui
Published: November 2012

Sand and fluid may both run into the wellbore during the production of loose sandstone reservoir, but cavities around the wellbore are prone to form when sand is produced, which makes the casing lost the protection of the formation and casing failure comes about. The limitation of thin cylindrical shell buckling model is analyzed and a mechanical model for casing under sand production is established by M.M.протодьяконоВ’ theory and the pressures of the casing where cavities exist are determined by numerical method. The research shows the cavity height and sand production volume are in a power relationship; the cavity height and axial force are in a linear relationship. With the increase of the overburden pressure, higher steel grade have to be used to keep the reliability of the casing. The research provides theoretical foundation for production casing design and casing strength verification with reasonable sanding.
Wave Induced Deformation and Stress Responses in HDPE Circular Net Cage: A Numerical Approach
Authors: Du Jian Hang , He Zhen , Yan Feng Lin , Yu Guo Yan
Published: November 2012

A 3D numerical model was developed to analyze the deformation and stress characteristics of HDPE material circular net cage exposed to waves, using the finite element method (FEM). The total wave forces acting on the structure were evaluated with method combining analytical and numerical, and served as boundary conditions during the simulation. Testing cases were performed eventually based on the actual conditions in Zhanjiang bay. The results show that wave height is an important factor that affects the dynamics response characteristics of net cages as well as the working conditions of the cages in sea environment, and the peak stress of the flotation structure always occurs at the mooring points. We also suggest that the net cages that constructed inside Zhanjiang Bay may not fail even during the storm process when in normal working condition.
Solid State Chemical Reaction Synthesis and Characterization of Nanocrystalline Cerium Oxalate under Ultrasonication Spectra
Authors: Li Dao Hua
Published: November 2012

Under the conditions of the presence of surfactants and ultrasonication, the use of different cerium salt, respectively, with oxalic acid under solid state chemistry reactions, the synthesis of nano-rare earth metal complexes of cerium oxalate crystals was formed. The solid phase was characterized by powder X-ray diffraction (XRD) and electron diffraction (ED). The particle size, its distribution, and morphology of the prepared nanocrystallite were observed by transmission electron microscopy (TEM). The results show that particle sizes are relatively uniform, the morphology of the crystal is spherical, the average particle diameter is about 40 nm, and the yield rate is approximately 91.6%. Furthermore, during the synthesis, the solid-state reaction conditions including raw materials, matching proportion of reactants, additions of inert substance, addition of trace solvents, surfactants and porphyrization time, etc, all have some influence on the morphology, particle size and size distribution of the final products. During the synthesis of the cerium oxalate nanocrystallines, the solid state reaction conditions such as changing reactant, matching proportion of reactant, adding inert substance, joining a little solvent or surface active solvent and grinding at different times may influence morphology, particle size and the size distribution of final products.
Application of the R-Function Theory and Least Square Method for Torsion Problem with H-Shaped Cross-Section
Authors: Li Ping Ping , Yuan Hong , Li Shan Qing
Published: November 2012

The R-function theory and least square method are employed to solve the torsion problem of the bar with H-shaped cross-section. When the least square method is used to solve the elastic torsion problem alone, the stress function can be set to meet the boundary condition, only with the simple cross-section such as the rectangle and ellipse. For the H-shaped cross-section, it is hard to find a stress function to meet the boundary condition. The R-function theory can solve the problem, and it can be used to describe H-shaped cross-section by implicit function form. Introducing the R-function theory can be easy to construct the stress function that satisfied the boundary of H-shaped cross-section. A numerical example demonstrates the feasibility and efficiency of the present method.
Stress Analysis under Cu Bump Bonding Process
Authors: Huang Chun Yue , Liang Ying , Wu Song , Li Tian Ming
Published: November 2012

The copper wire has some advantages in thermal performance, mechanical performance, and low cost, which make it can provide the lowest cost flip-chip(FC) package for low I/O density device. The 2D Cu stud bump finite element model was set up by using ANSYS/LS-DYNA with LOLID162 element to dynamic simulate the Cu stud bump bonding shaping process. The stress distribution in the Cu stud bump and the pad during the bonding process were studied, and the influence of pad thickness on the stress distribution of Si chip was also analyzed. The results shows that under the bonding process the Cu bump height is mainly influenced by the bonding pressure and the top shape of the Cu bump is influenced by ultrasonic energy, the increase of pad thickness results in reducing stress concentration inside the Si chip.
On the Measurement of Roller Skew of Tapered Roller Bearings
Authors: Falodi Abiodun , Chen Yong K. , Caspall Martin , Earthrowl Brian , Dell David
Published: November 2012

Roller skew in roller bearings can cause heat generation and reduce bearing life. Therefore, design to minimise its occurrence is essential in bearing development. This study investigated the roller skew of a double row tapered roller bearing under various running conditions. A new system of measurement using two differential variable reluctance transducers (DVRT) was developed. It is evident that the roller skew of the double row tapered roller bearing can be measured. The shaft rotational speed has a significant effect on roller skew but the radial load has little effect.
A Consistent Formulation of Constitutive Relations for a Model of Nonlocal Viscoplasticity
Authors: de Angelis Fabio , Cancellara Donato
Published: November 2012

Constitutive relations are presented for a model of nonlocal viscoplasticity within a variationally consistent suitable setting. The appropriate elastic and dissipative potentials are introduced within a generalized standard material framework. A formulation of variationally consistent constitutive relations is accordingly presented for a model of nonlocal viscoplasticity. The evolutive equations are illustrated for the proposed model in a general form which is able to include different models of nonlocal viscoplasticity and different hardening rules.
Quality Assessment of Weldable Steel Mark P355NH from Decompression Chamber Construction for Diving
Authors: Pascu Romulus , Roşu Radu Alexandru , Duma Iuliana , Dascau Horia
Published: November 2012

Non-alloyed P355NH steel according to EN 10028-3:2003 belongs to a group of fine-grained steels for pressure vessels being used in welded construction at decompression chamber for divers. Values of the chemical, structural and mechanical characteristics and steel toughness experimentally determined fit the analyzed steel in P355NH steel group according to EN 10028-3:2003. The toughness of the analyzed steel at the test temperature of -30°C is characterized by high values of fracture energy KV in longitudinal direction between 48 and 86 J and on transverse direction between 17 and 34J. Steel toughness at the test temperature of -30°C required by ABS standard (in Section 4/5.3 and Table 1) provides for breaking energy KV of min. 35J, with ductile fracture surfaces, value that is not respected at some lots of the three batches (A, B, C) of steel. Finally, based on the direct correlation established between HV10 hardness of the fine structure and the toughness it was made a selection of the lots of non-alloy steel P355NH which correspond to ABS norm for welded construction of the decompression chamber for divers
Influence of Low-Level Voltage in Pulse ECM on Electrode Wear and Machining Accuracy
Authors: Endo Katsuaki , Natsu Wataru
Published: November 2012

It is well-known that using pulse voltage could improve the machining accuracy in ECM process. However, the tool electrode wear occurs under some machining conditions in pulse ECM. In order to acquire the high machining accuracy, a method to eliminate the electrode wear by raising the low-level voltage was proposed and the relation between the low-level voltage and the machining accuracy was experimentally investigated in this research. It was found that the low-level voltage of 2V could not only prevent the tool electrode wear, but also improve the machining accuracy and the machining speed. In addition to the low-level voltage, the influence of the pulse duty ratio on the tool wear, the machining speed and accuracy was investigated. It was found that the raised low-level voltage was also effective when the duty ratio was increased and the increased duty ratio itself reduced the tool electrode wear.
Thermal Deformation in a Static Pressure Dry Gas Seal
Authors: Zhu Wei Bing , Zhou Sheng Ren , Wang He Shun
Published: November 2012

Based on the basic principles of heat transfer, the two-dimensional stable state cylindrical coordinate solid heat conduction differential equation having no inner heat source is established. Use the ANSYS software to establish the temperature field finite element analysis model of rotating and stationary rings and carry on the solution to the temperature field. The temperature distributing rules of rotating and stationary rings are obtained at the same time. According to thermo-elastic deformation theory, numerical analysis method and separation method are applied to resolve and analyze thermal-structural coupling deformation of rotating and stationary rings.
Wear Resistance of Nano TiN Strengthen High Chromium Cast Iron
Authors: Shao Xing Hai , Xie Jing Pei , Wang Wen Yan , Li Yan , Zhou Pin Gan , Yu Hui Wu
Published: November 2012

The effects and the mechanisms of namo TiN on the high chromium cast iron are studied, the material has been prepared through infiltration casting and addition of high carbon ferrochrome powder and nano TiN powder. The alloy is formed on the surfaced of guide plate, and the wear resistance of alloy have been studied by means of SEM, XRD micro-analysis and wear-resistant performance. The grain size and the type of carbide in the organization are affected by nano TiN, and the wear resistance of carbon chromium alloy layer is affected by the type of carbide; when the addition of nano TiN is 1% (wt), the grain size is apparently refined, overeutectic primary M7C3 in the hypereutectic is precipitated uniformly in considerable amounts, therefore the wear resistance of alloy can be improved effectively.
A Practical Evaluation Approach to Form Deviation for Surface of Revolution Based on Discrete Point Coordinate Data
Authors: Qiu Hua , Kubo Akio
Published: November 2012

This paper proposes a practical evaluation approach to form deviation for surface of revolution based on discrete point coordinate data. An approximate curve composed of circular arc segments decided from an optimal interpolation process is accepted for computing the form deviation at measured points instead of the generating line of the surface to be inspected. This operation significantly simplifies the algorithm and improves the efficiency in the evaluation calculation. At the same time, it is also guaranteed that the difference of both form deviation values relative to the approximate surface or to the original surface is restricted within the specified accuracy in the circular arc interpolation operation. The effectiveness and efficiency of the approach are verified through a practical example of the surface of revolution with a generating line in the form of cubic Bézier curve.
Temperature Model of an Advanced Artificial Lift Technology--Cyclic Nature Gas Heat Insulation and Geothermal Temperature Heating Technology
Authors: Li Ang , Chen De Chun , Meng Hong Xia
Published: November 2012

In view of the questions that heavy oil has badly flow condition and lifting efficient, and considering low carbon, energy conservation and environment as goal, an advanced artificial lift technology of cyclic nature gas heat insulation and geothermal temperature heating is developed, and the temperature calculation model of the technology was founded. The analysis that different cyclic nature gas volume, cyclic depth and oil production affect the formation produced fluid temperature distribution was made. The result is that the formation produced fluid temperature increases with the addition of cyclic depth and the function of rising temperature decreases from cyclic depth to wellhead, and that the formation produced fluid temperature increases with the addition of oil production and cyclic nature gas volume. A certain well as example, using the technology, the formation produced fluid temperature increases 11.14°C, compared to the conventional artificial lift technology. And it is favorable for surface transportation.
Prediction of Heat Dissipation Effect by Simulating Radiator Group of Mining Dump-Truck
Authors: Fan Zun Jin , Gu Zheng Qi , Liu Shui Chang
Published: November 2012

This paper is concerned with prediction of heat dissipation effect by establishing a 3d geometric model of the radiator group for a ribbon-tubular radiator of a mining dump-truck. By using the CFD approach the airflow characteristics of the radiator group are numerically calculated, and the resistance characteristic and heat transfer performance are analyzed thus the matching point of the fan is calculated, and the heat transfer performance of the water-side is simulated. Then, according to the relative heat transfer theory, the inlet and outlet water temperature of the radiator group under idling condition is obtained by analytical method. The experiment is done subsequently. The maximum deviation rate between the results of the simulation and the experiment is 6.4%, which can meet the engineering requirement and well predicts the heat dissipate performance of the radiator group. The result indicates that by combining the CFD numerical simulation with the analytical method the heat dissipation of the radiator group can be predicted effectively.
Sub-Optimal Control for Nonlinear Heat Equations
Authors: Zong Xi Ju , Cheng Xin Gong , Zhang Yong
Published: November 2012

This paper presents a successive approximation approach (SAA) designing optimal controllers for a class of nonlinear heat equations with a quadratic performance index. By using the SAA, the optimal control problem for nonlinear heat equations is transformed into a sequence of nonhomogeneous linear differential Riccati operator equations. The optimal control law obtained consists of an accurate linear feedback term and a nonlinear compensation term which is the limit of an adjoin vector sequence. By using the finite-step iteration of the nonlinear compensation sequence, we can obtain a suboptimal control law.
The Gas Phase Reaction Crystallization Mechanisms of Amorphous SiCN Ceramic Annealed in Vacuum
Authors: Xia Yi , Li Hong Fang
Published: November 2012

Microstructures of precursor-derived amorphous SiCN ceramics under conditions of vacuum and high temperature (1300°C, 1900°C) were observed by transmission electron microscopy. The gas phase reaction crystallization mechanisms of amorphous SiCN in vacuum was investigated based on thermodynamic calculation. The results indicate vacuum heat treatment can promote decomposition, induces gaseous species (SiO, CO and Si vapor) production. Gas phase reaction between Si(g), SiO(g) and C induces SiC nucleation inside amorphous ceramic network. Free Si- and N- can not form Si-N-enriched regions and N- is discharged in the form of N2. The crystallization of amorphous SiCN in vacuum displays significant difference to that in N2 and Ar.
Research on Structural Analysis of Steering Based on Thermal-Structure
Authors: Qin Hong Wu , Wang Qi Tang , Yang Wen Hua , Li Zheng Sheng , He Ren
Published: November 2012

Stiffness and strength of the electric power steering structure were analyzed based on Catia, HyperMesh and ANSYS. Then, the influence of temperature on the stiffness of every component was also studied. The results indicate that the maximum deformations of the worm and worm wheel occur in the centre of the tooth top and their shape approximate ellipse. The deformation of the tail end of the worm-wheel shaft is large, and the limited groove area contracting the splined shaft and the steel ball bears large stress. The temperature load has some impact on the stress and deformation of components. The deformations of the components gradually enlarge with the increasing of the temperature, but the variations are not large. The stiffness and strength of steering can meet the design requirements.
Study of Modification Mechanism of Ultrafine Silica Modified by PAMAM
Authors: Tao Jin
Published: November 2012

Ultrafine silicon dioxide were modified by -NH2-teminated poly(amido-amine) (PAMAM) dendrimers to improve their dispersibility in the coatings. The modification mechanism was studied through density functional theory (DFT) in the gas phase. Virous initial configurations of ion bound to PAMAM were established to investigate the structures and the energetics of the complexes. Two stable conformers are found: types A ( is bound to the amine site) and C ( is bound to the amide site). Types A and C indicate the chemical bond formation of Si-N and Si-O, respectively.
Rolling Bearing Fault Diagnosis Based on Blind Source Separation
Authors: Chen Chang Zheng , Meng Qiang , Zhou Hao , Zhang Yu
Published: November 2012

This document presents fault diagnosis method of rolling bearing based on blind source separation. The algorithm based on fast ICA is improved to separate fault signals according to the rolling bearing’s fault characteristics. Through the experiment it is shown that the algorithm can separate the signals collected from rolling bearing and gearbox effectively, which can provide a new method for fault diagnosis and signal processing of machinery equipment.
System of Premixed Abrasive Jet Cleaning and Derusting on Steel Tube Inwall
Authors: Liu Li Hong , Cao Huan , Zou Chen Qi
Published: November 2012

The pretreatment of the tube wall's surface needs to be done before coating and plating. The cleaning and derusting play an important role in the pretreatment. This paper designs the cleaning and derusting system of the steel tube inwall by premixed abrasive jet technique. The system consists of the generating device of premixed abrasive jet, the abrasive retrieval device and working mechanism. The test of clean and derust were carried on steel tube inwall by the system. In the test, the large inner diameter of pipe fittings adopted the oblique type nozzle, the small ones adopted the conic abrasive jet nozzle. The test shows that the designed system can achieve the purpose of cleaning and derusting on steel tube inwall. The appropriate working parameters: the working pressure is 12MPa, the rate of water flow is 30L/min, the abrasive weight consistency is 30%.
The Application Research of PIC16F877 in the Pulse Power of WEDM-HS
Authors: Gao Yi
Published: November 2012

The main research of this paper is the influence of the main control circuit of WEDM-HS' pulse power on wire-cutting processing efficiency,make design improvement for the main control circuit of WEDM-HS' pulse power, put forward the corresponding countermeasures and solutions to the problems that the pulse power supply output current waveform is not steep along the before and after and it difficult to take digital adjustment in pulse width and interval.
Development of In Situ SAXS Detection System for the Pre-Oxidation and Carbonization of PAN Precursor
Authors: Yu Kuan , Zhu Bo
Published: November 2012

We designed an in-situ detection system suitable for Shanghai Synchrotron Radiation Facility. The system integrates remote control, temperature control, high-precision servo control and tension control technology, and can dynamically track the microstructure evolution of PAN precursor in the pre-oxidation and carbonization process using SAXS technology. The system has been put into use at the beam line BL16B1 at Shanghai Synchrotron Radiation Facility to investigate the structural evolution of PAN fibers with different drafting tension, temperature and atmosphere.
New Methold on Power Transformer Fault Diagnosis
Authors: Wang Nan Lan , Cai Ming Shan
Published: November 2012

This paper improves the simple genetic algorithm and combines genetic algorithm with BP algorithm to the wavelet neural network in the power transformer fault diagnosis by dissolved gas-in-oil analysis, Simulation result shows the problem was solved that wavelet network settles into local small extremum so easily that the network surging will increase and the network will not be convergent if the initialization is unreasonable, and overcomes the shortcoming that the speed is too slow if use genetic algorithm to train neural network independently.
Pre-Buckling Transverse Free Vibration of an Asymmetrically Supported Euler Beam Subjected to Distributed Follower Forces
Authors: Li Qing Lu , Li Shi Rong
Published: November 2012

Based on the accurate geometrical theory for the extensible elastic beams, an exact mathematical model of post-buckling transverse free vibration of Euler beams subjected to a distributed tangential follower force along the central axis are established. By using shooting method, pre-buckling free vibrations of both simply supported and fixed Euler beam are solved and the responses of small amplitude vibration are obtained. The numerical results show that all the frequencies of unbuckled beams decrease continuously with the increment of the load parameters.
The Effect of Damper Components on the Performance of Impact Damping
Authors: Du Yan Chen , Zhang Ming Ming
Published: November 2012

This paper studies the effect of damper components on the performance of the impact damper with fine particles as damping agent (IDFPDA). The responses of various damper combinations are obtained from the experiments of a cantilevered beam attached by the IDFPDA with different impactor diameter and particle material. Results show that the average attenuation rate is 72.7~75.4% by changing the particle material in IDFPDA and the average attenuation rate is 72.1~75.9% by changing the diameter of impactors, which are much higher than that without particles or impactors. The conclusions can be drawn that the IDFPDA has more excellent performance than traditional impact damper only with impactors or particles. The impactor diameters and the particle materials have little effect on the damping performance, so both metal and non-metal particles are suitable to IDFPDA.
Analysis and Design of PCB Multistage Process Quality Management Information System
Authors: Chen Xiao Rong , Bai Lin , Wu Tong
Published: November 2012

This paper analyses the actual applications demand of the real-time PCB production quality management information system for the electronic product manufacturing enterprises, has established functional model for the real-time PCB production and quality management information system, and has used of mathematical statistics and mathematical logic principles, methods to analyzed of PCB production quality information, which was collected in real-time, finally, has established a Quality Information System PCB, this system achieves the various production processes and product quality tracking and retroactively for PCB.
High-Speed and High-Accuracy Schemes of Coordinate Calculation and End Point Judgment for Elliptic Interpolation
Authors: Wang Shi Yong , Li Di
Published: November 2012

To implement high-speed and high-accuracy elliptic interpolation required in high-performance motion control, novel coordinate calculation and end point judgment schemes are proposed. Data Sample method is used for coordinate calculation. High accuracy is guaranteed by avoiding approximation calculation of interpolation points. Exact end point judgment is constructed based on the position relationship of the current interpolation point, the next interpolation point and the end point to avoid incomplete interpolation or over interpolation of elliptic trajectories. The proposed schemes feature fewer amounts of calculation and high accuracy and can produce any elliptic trajectories.
Preparation and Application Study of Nano-Sized Organic Bentonite Used for Composite Flame Retardant
Authors: Liu Shu Guang , Zhang Zhen Yi , Peng Hui , Wang Xu
Published: November 2012

Nono-sized organic bentonite (OMMT) was synthesized through intercalation modification process with organic phosphorus flame retardant (Cyagard RF-1) and quaternary ammonium salt (CTAB). Composite materials of polybutylene terephthalate (PBT)/OMMT, Polyamide-6 (PA6)/OMMT was prepared by a double screw extrusion. The flame retardancy and mechanical properties of these materials were characterized. Nano-sized OMMT has large interlayer spacings and good dispersion after modification. In compared with PBT and PA6, composite materials of PBT/OMMT and PA6/OMMT had high tensile strength, bending strength and notched impact strength, while their elongation decreased after addition of nano-sized OMMT, the limiting oxygen index ( LOI ) and UL94 vertical combustion of OBT/OMMT and PA6/OMMT composite materials with dosage of 3 wt% OMMT decreased slightly, in comparison with these composite metarials containing constant amounts of flame retardant.
Gear Fault Diagnosis Based on Harmonic Wavelet Packet and BP Neural Network
Authors: Jiang Chen , Weng Xue Tao , Lou Jing Jun
Published: November 2012

The gear fault diagnosis system is proposed based on harmonic wavelet packet transform (WPT) and BP neural network techniques. The WPT is a well-known signal processing technique for fault detection and identification in mechanical system，In the preprocessing of vibration signals, WPT coefficients are used for evaluating their energy and treated as the features to distinguish the fault conditions.In the experimental work, the harmonic wavelets are used as mother wavelets to build and perform the proposed WPT technique. The experimental results showed that the proposed system achieved an average classification accuracy of over 95% for various gear working conditions.
Study on Chip-Breaking Technology for Numerical-Control Varying-Feed Drilling of Deep Hole
Authors: Ma Qing Yan , Wang Biao , Yu Da Guo
Published: November 2012

In the drilling process for deep hole, the continuous chips often jam up due to the difficulty of chip removal, and the chips cause problems such as tool breakage and deterioration of the surface quality. The measures of chip removal must be adopted, especially for small diameter deep hole, the chip removal space is limited and thickness and length of chips can directly influence the chip removal, the chip size are required as a precondition for chip removal. In this study, the feed is periodically varied in numerical control machine, and the length of chip can be controlled, then the chip breaking is realized with no addition special chip breaking mechanism, which combines with negative pressure suction mechanism for chips, and solves the problem of chip breaking and removal.
Research on a Method of Fault Signal Extraction Based on Improved Algorithm
Authors: Wang Ying , Li You Rong , Zhu Xiao Qin , Lin Pan , Luo Yue Sheng
Published: November 2012

Considering the difficulty of diagnosis signal de-noising and feature extraction problems, according to the characteristics of periodicity and shock attenuation respond of mechanical fault vibration signals, a method of improved sequential decomposition algorithm is proposed, it transforms an initial time series into a group of two-dimensional time series, prominent time series partial information, time series decomposition is reversible, can be used for filtering and feature extraction of time signal. Through the simulation and experiments, the validity of method for highlighting partial feature information of the signal is verified, helping to extract weak fault information in strong background noise environment.
The Error Analysis and Detection of A/C Axes Bi-Rotary Milling Head
Authors: Zheng Peng , Yi Lan
Published: November 2012

A/C axes bi-rotary CNC universal milling is the core components of five-axis linkage machine tools, the geometric error will impact on machining accuracy directly. The geometric error and its causes of A/C axes bi-notary milling head are studied, and laid the foundation for the bi-notary milling head precision testing and accuracy improvement. Brief introduction to the composition and working principle of the Renishaw laser interferometer, and put forward by using of Renishaw laser interferometer to detect the A axis and C axis position error.
Fault Diagnosis of Chemical Process Based on ACO-BP Neural Network
Authors: Chen Jian Xue
Published: November 2012

Fault diagnosis is an important problem in the process of chemical industry and the artificial neural network is widely applied in fault diagnosis of chemical process. A hybrid algorithm combining ant colony optimization (ACO) algorithm with back-propagation (BP) algorithm, also referred to as ACO-BP algorithm, is proposed to train the neural network weights and thresholds. The basic theory and steps of ACO-BP algorithm are given, and applied in fault diagnosis of the continuous stirred-tank reactor (CSTR). Experimental results prove that ACO-BP algorithm has good fault diagnosis precision, and it can detect the fault in CSTR promptly and effectively.
Effects of Pre-Ageing on Thermomechanical Treatment Process of 2A12 Aluminum Alloy
Authors: Zhang Shi Xing , Zhu Yu Ping , Wu Hai Hong
Published: November 2012

The thermomechanical treatment of a 2A12 aluminum alloy was researched and the influence of pre-ageing on microstructure and hardness was analyzed emphatically. The results reveal that the hardness of specimen increases when they are pre-aged, the hardness value rises at first and then decreases, reaching the maxmum value when pre-aged at 180°C×30min . After plastically deformed at 450°C, the hardness keeps on increasing, and the grains are equiaxed polygon structure. After all the workpieces are aged in the end, the small particles of the second phase precipitates completely and disperses within the original phase matrix, the particles interact with dislocations in upper state that formed during plastic deformation and lead to a great increase in hardness compared with as-received. the best pre-aging parameter is 180°C×30min.
Effect of Electromagnetic Stirring Process Parameters on Semi-Solid Fluid Field of Aluminum Alloy
Authors: Long An , Ge Rui , Chen Yin , Hu Kuan Hui
Published: November 2012

To research the effect of electromagnetic stirring process parameters on the parts’ quality in semi-solid forming of aluminum alloy, the material of ZL017 was heated and melted, and electromagnetic stirred under different frequency and power, then material microstructure gained by different process parameters was observed. The elementary alteration rule of fluid field was analyzed with the alteration of stirring frequency, current density, stirring time，stirring temperature and fluid viscosity. Suitable process parameters for electromagnetic stirring of ZLl07 was concluded.
The Heterogeneity of Composition and Microstructure in Cast Large Sized 3104 Alloy Slab
Authors: Huang Rui Yin , Yin Zhi Min , Zhu Yuan Zhi
Published: November 2012

Heterogeneity of composition and microstructure in cast large sized 3104 aluminium alloy slab were studied using AES-ICP, OM, SEM, etc. The results show that the cooling rate on the cross section of 3104 slab is different, macro-segregation is found in the different section in the slab .The content of Ti decreases gradually from the surface to about 1/4 thickness of the slab, then increases rapidly to the center of slab; other elements content increases gradually from the surface to the about 1/4 thickness and then decreases rapidly to the center; the grain size on the surface area is fine, and the grain size at the center is coarse , segregation of Mg is found within the grains; great amount compound is found to be of presence on the grain boundary, with chemical compositions of Al 87（FeMn）13 and Al83（FeMn）12Si5; The compound size at the surface area is comparatively smaller, and coarser at the centre of slab.
Influence of Jacket and Filling Materials Characteristics on PELE Effects
Authors: Zhang Hong Cheng , Yin Jian Ping , Wang Zhi Jun
Published: November 2012

Numerical simulations of different PELE jacket and filling materials are carried out to research the influence of the materials characteristics on PELE effects. The results indicate that the materials characteristics have obvious influence on PELE effects. For jacket materials, the elastic modulus and density are the key factors that influence PELE effects, the maximum radial speed and scattering angle of fragments, and the penetration hole size of 4340 steel are larger than these of tungsten alloy, thus the PELE effects of 4340 steel are better. For filling materials, the elastic modulus is the key factor influencing PELE effects, the maximum radial speed and scattering angle of fragments, and the penetration hole size of PE, nylon and aluminum increase successively, the aluminum filling material has better PELE effects.
Rheological Behavior of Semisolid AlSi6Mg2 Alloy at Transient State
Authors: Ju Li Ping , Wu Ying , Xu En Sheng , Wang Wei , Luo Hong Chao
Published: November 2012

In the present work, basing on the rheological model of Chen and Fan [1], the rheological behavior of AlSi6Mg2 alloy at transient state is investigated. It has been shown that the deagglomeration of particles is about two orders of magnitude faster than the agglomeration of them. The inequality of agglomeration rate and deagglomeration rate is thought as the origin of the thixotropy of SSMS. Subsequently, the similar trend of the variation of the viscosity and the average agglomerate size with shearing time and resting time shows that the microstructure of SSMS determines its rheological behavior, while the external flow conditions (such as shear rate, shearing time, etc) influence the viscosity by changing its microstructure. The present study predicts that the CF model can describe reliably the transient rheological behavior of AlSi6Mg2 alloy.
Calculation Model of Mass Action Concentrations for CaO-Al2O3-SiO2 Slag System
Authors: Wang Hong Ming , Li Gui Rong , Zhu Xiang , Zhao Yu Tao
Published: November 2012

According to the coexistence theory of melted slag structure, a calculation model of mass action concentrations for CaO-Al2O3-SiO2 slag system has been established, by which the mass action concentrations of all structure units in CaO-SiO2-Al2O3 systems are calculated. The effects of Al2O3 content and slag basicity on the mass action concentrations are investigated. The results indicate that both basicity and the content of Al2O3 have remarkable effects on mass action concentrations of CaO, 2CaO•SiO2, CaO•SiO2, CaO•Al2O3 and 2CaO•SiO2•Al2O3, etc. Furthermore, the effects of Al2O3 content on mass action concentrations are relevant with slag basicity. The basicity has more influences on mass action concentrations of CaO, CaO•SiO2, 2CaO•SiO2 and 3CaO•SiO2, whereas the basicity has little effect on mass action concentrations of other structure units in CaO-SiO2-Al2O3 system.
Analysis on Fatigue Crack Propagation and Fractography of A7075 Aluminum Alloy
Authors: Chao Xu , Yang Shang Lei
Published: November 2012

The fatigue fractography and surface of A7075 aluminum alloy was investigated by means of optical microscope, scanning electron microscope and technology of metallurgic replica. The results show that the fatigue crack generally initiated in the surface or near the surface of the sample area, such as hole and inclusion. The crack propagation regions under high stress amplitude was characterized by furrow and hollow, and obviously presented fine ripple vein. While lots of fatigue striations and sidesteps with the holes and secondary cracks generated in the crack propagation regions of low stress amplitude. Fatigue transient breaking area is a mixed fracture of brittle and ductile fracture. In the fatigue crack propagation stage, with the increasing of cycle times, secondary cracks gradually merged into primary crack on the path of crack propagation. The dislocation of crack tip,grain boundaries and different grain orientations have great influence on the path of crack growth, which can make cracks bending.
Very Long Life Fatigue Behavior of Q345 Bridge Steel
Authors: Zhao Xiao
Published: November 2012

Using the ultrasonic fatigue testing technique, specimens of Q345 bridge steel with two types of shape (round and plate) were performed in ambient air at room temperature with a stress ratio of R=-1. The very long life fatigue property of Q345 was studied and the initiation mechanisms of fatigue cracks were investigated and analyzed with SEM. The results show that the two types of specimen present different S-N curve characteristics in the region of 105-109 cycles. The S-N curve of round specimens shows continuously decreasing tendency, while the S-N curve of plate specimens has a steep decreasing step and an asymptotic horizontal one. The fatigue strength of round specimen is higher than that of plate specimen. Fatigue failure initiates from the surface before 107cycles with high stess level while at internal inclusion in the very long life fatigue regime.
The Corrosion Behavior of a Low Carbon Bainite Steel in Simulated Atmosphere Environment Containing Chloride and/or Sulfide
Authors: Cui Lei , Yang Shan Wu , Kong Jun Hua
Published: November 2012

The corrosion behaviors of a low carbon bainite steel in three atmosphere environments simulated by corresponding solutions were investigated in this accelerated test. It is found that the corrosion rate of the low carbon bainite steel is lower than that of the commercial weathering steel 09CuPCrNi in all the three solutions. The corrosion rates of the bainite steel in the three solutions are also different, which is most serious in the solution containing both chloride and sulfide. There is no serious selective corrosion, for the corrosion has little effect on the mechanical property of the bainite steel. Corrosion rates are relation to the amount of Cu and Cr enrichment in rust layers, which are well corresponding to the specific surface area values of corrosion products. Inhibit effect can be found in the solution containing both chloride and sulfide.
The Analysis of Magnesium Compound Desulfurizer and Compound Desulfurizer in PANGANG
Authors: Chen Yong , Liang Xin Teng , Zeng Jian Hua , Li Gui Jun , Huang Zheng Hua
Published: November 2012

This paper firstly analyzed the desulfurization mechanism of magnesium compound desulfurizer and compound desulfurizer. It is thought that the compound desulfurizer which contains a certain amount of magnesium is better used than the one does not contain. There is also the statistical analysis about these two type desulfurizers in practical Producing. The practical application of contrast verifies the theoretical analysis.The magnesium compound desulfurizer has better performance used in the effect of desulfurization, the consumption of desulfurizer, iron loss, process-time, the loss of hot metal temperature and the lance life than compound desulfurizer.
Effect of Electromagnetic Stirring on Morphology Evolution of Mg2Si in Hypereutectic Al-Si Alloy Composite
Authors: Liu Zheng , Xu Hong Biao , Zhou Zhi Peng , Xu He Jun
Published: November 2012

Mg2Si reinforced hypereutectic Al-Si composite was prepared and the effects of electro- magnetic stirring on Mg2Si particle in the composite were researched. The results indicated that there were the important effects of electromagnetic stirring on size and morphology of the particle in the composite. The morphology and size of the particle in the composite were obviously improved by electromagnetic stirring. In comparison with the sample without isothermal holding, the size of the particle isothermally held slightly increased under the same stirring condition, but the roundness of the particle was improved. After isothermal holding, the mechanical properties of the composite prepared by electromagnetic stirring were improved to some extent.
Study on Corrosion Behaviors of the PTA Plant in Halogen
Authors: Wang Jin Gang , Gao Ying
Published: November 2012

In the acetic acid solution containing bromine ions, Br- has strong penetration ability, which cause PTA production device serious pitting corrosion, and even perforation failure. This paper use the immersion method and the electrochemical experiment, to study the corrosion behaviors of austenitic stainless steel which is commonly used in equipment 316L and 1Cr18Ni9Ti in the acetic acid solution containing bromide ions. The results show that: In a certain temperature range, as the temperature rising, 316L and 1Cr18Ni9Ti's annual average corrosion depth shows the changing law of type curve. At the start, the annual average corrosion depth increases rapidly, and after the passivation film formation, the rate of increase slows. With the increase of the Br- concentration, 316L and 1Cr18Ni9Ti's corrosion rate increases, but apparently the 316L than 1Cr18Ni9Ti slow growth of many.
Evaluation of Mechanical Properties of Polyamide 6(PA6) Filled with Wollastonite and Inorganic Modified Wollastonite
Authors: Wang Cai Li , Zheng Shui Lin , Wang Huai Fa
Published: November 2012

Some novel composites were prepared with polyamide 6(PA6) filled with wollastonite particles and wollastonite inorganic modified by aluminium silicate composite materials (WIMS) as fibrous fillers. Subsequently, these composites were investigated for tensile, charpy notched impact, bending strength, bending modulus and heat distortion temperature, and the mechanism of PA6 reinforced by WIMS was discussed through SEM photos of wollastonite and WIMS and the current two most popular equations: Pukanszky equation and Nielsen equation.The results show that the PA6 products filled with WIMS have superior mechanical properties(tensile strength 71.65Mpa, bending strength 106.61Mpa, bending modulus 3258.22Mpa) than that of uncoated wollastonite and pure PA6, and the heat distortion temperature increases by 88.6°C than pure PA6 and 17.2°C than wollastonite. Inorganic modification of wollastonite can improve the joint interface between wollastonite and PA6, thus improving their mechanical properties.