bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and Performance of Compound Polyurethane Foam Plastic Board for Freezing Prevention in Channel Lining
Authors: He Wu Quan , Cai Ming Ke , Wang Yu Bao , Zheng Shui Rong
Published: February 2011

The influence of different particle size and filling amount of particles of cornstalks on the density and compressive strength of polyurethane foam plastic board has been studied in this paper. The results indicate that the comprehensive properties of polyurethane foam plastic board is better when the particle size varies from 0.45 to 1.5mm and the filling amount is 30% which could meet the needs of avoiding the frost heaving failure in the canal lining blocks. And compared with the foam plastic board without filling particles, the property can be equal with particles of cornstalks filled in, but the cost can be reduced about 25%. Meanwhile, the cornstalks are fully reused, which also help protect the environment.
Calculation Method of Butt-Welded Connection of Steel Structure Post Fire
Authors: Chen Jian Feng
Published: February 2011

In order to study the load-bearing properties of butt-welded connection of steel structure post fire, the strength design value of weld connection post-fire is proposed based on the experimental data and theoretical analysis. Considering the influence of different high temperatures and cooling patterns on strength damage of the weld, a revised checking method for strength of butt-welded connection of steel structure after high temperature is established on the basis of the analysis method for strength of butt-welded connection of steel structure at room temperature. The method can be used for damage assessment and strengthening technique of steel structure post fire.
On the Hardfacing Performance Optimization after Plasma Transfer Arc Experiments
Authors: Jean Ming Der , Li Ming Cheng , Chien Tzu Hsuan , Chen Ching Jyi
Published: February 2011

The paper describes response surface methodology (RSM) based on design of experiments and analysis of variance (ANOVA) as a statistical design while developing a robust plasma transfer arc (PTA)coating process. Based on ANOVA, The relative important parameters with respect to surface at hardness values were identified in the Taguchi design, where they were further used in predictors. In addition, we applied three-dimensional graphs in RSM to develop a robust PTA response surface yielding the desired-better area of a treated layer. In this study, a quadratic polynomial with a Box-Behnken design is utilized. The results reveal that RSM provides the effective methods as compared to the traditional trial-and-error method for exploring the effects of controlled factors on response. A very good agreement was observed, as evidenced by R-squared value, 90%, between the predicted and the experimental data, and its error percent is found to be approximately 3.801% in the PTA-coating process. It is clear that RSM model demonstrated better accuracy in predicting surface hardness for PTA-coating process. Accordingly, RSM based on design of experiments was used as statistical PTA-coating design tools combined with the hardness model. Device zone optimization and yield enhancement have been demonstrated.
Investigation on Inconel 625 Alloy Thin-Walled Parts by Direct Laser Fabrication
Authors: Gao Shi You , Zhou Ye Fei , Xi Ming Zhe
Published: February 2011

In this paper, the process of direct laser fabricating (DLF) thin-walled parts with Inconel 625 alloy was studied. The interrelationship between deposition quality and process parameters has been analyzed in the aspects of laser power. Scanning velocity, powder feed velocity, z-increment. The further investigations of study lie on the influence of process parameters on geometrical characterization of single cladding layer, the Axis-Z increments on height of thin-walled part, as well as the microstructure of fabricated sample of Inconel 625. The results based on above experiments show that the Inconel 625 alloy parts can be fabricated by direct laser fabrication method and the samples were fully dense, homogenous and free of defects with the parameters under a certain range.
Study on Microstructure and Properties of Slab Crystallizer by Laser Coaxial Cladding Strengthening
Authors: Tian Feng Jie
Published: February 2011

Adopted the compounding Ni-base alloy powder and properly mixed a few functional powders, the study on surface strengthening for slab crystallizer base material by substrate pre-heated and laser coaxial feeding cladding was investigated. The results indicate that the laser coaxial feeding cladding can effectively decrease cladding layer’s pores and crackers compared with laser pre-laid cladding, the cladding layer structure is compact, uniform with typical rapid freezing character and the structure can be controlled by compounding alloy powders. The elements of substrate and cladding layer infiltrate and dilute to each other, the bonding interface is good with metallurgic and tight combination and the rate of dilution is very low. The erosion resistance and thermal fatigue of substrate are improved evidently by this treatment.
Fabrication of In Situ TiC Reinforement Ti Matirx Wear-Resistant and its Wearing Performance at 500°C
Authors: Qin Lan Yun , Wang Wei , Yang Guang
Published: February 2011

TiC reinforced titanium matrix functionally graded materials （FGM） has been produced by processes of laser metal deposition through changing the powder feed rate of Ti and Cr3C2 powder. The OM, SEM, EDS methods were used to analyze the components and microstructure of the coatings. Microhardness and wearing resistance at 500°Ctemperature of the FGM coating were examined by microhardness tester and wear tester respectively. The results show that FGM coating reinforced by in-situ TiC apparently improved hardness of Ti alloy; the microhardness can reach HV1100, and present gradient distribution along deposition direction. Dry sliding wear properties of these FGM coatings have been compared with substrate materials wearing. The observed wearing mechanisms are summarized and related to detailed microstructural observations. The results show the wear resistance of the coating can be improved by 2.8 times.
Investigated on Residual Stress Field of Aluminum Alloy 7050T7451 with Fastener Holes by Laser Shock Processing
Authors: Jiang Yin Fang , Li Zhi Fei , Zhang Jian Wen , Fang Lei
Published: February 2011

Laser shock processing (LSP) is a new technique for surface strengthening of fastener holes. The process of LSP before hole-drilling was adopted. A finite element model was established to study the effects of laser shock parameters on the residual stress field of aluminum alloy7050T7451 with Fastener Holes. The results indicate that increasing the laser power density until a fixed value results in a large peak in the hole-edge surface residual compressive stress. The hole-edge surface residual compressive stress and the depth of residual compressive stress are both increased with the increase of laser pulse width. Multiple laser shock processing can improve the residual compressive stress greatly, and with the increasing number of shot, the strengthening effect is gradually diminished.
Ablation Characteristic Analysis of Short Pulse Laser Processing Composite Materials
Authors: Pan Yun Ping , Yang Wen Juan , Mo Yi Min
Published: February 2011

Short pulse lasers, including picosecond laser and femtosecond laser are involved to investigate the ablation characteristics of processing carbon fiber reinforced plastics (CFRPs). The ablation threshold of the femtosecond laser, 0.453 J/cm2, is twice higher than that of the picosecond laser 0.867 J/cm2, since the former generates an intense and shorter pulse and the atoms excitation and multi-photon absorption may occur as short as 10 ps or less. The ablation test also describes the processing qualities, where the femtosecond laser has processing abilities without visible thermal defects or charring over the picosecond laser.
Effects of Sheet Thickness on Residual Stress Distribution by Laser Shock Processing of 7050-T7451 Aluminum Alloy
Authors: Jiang Yin Fang , Fang Lei , Li Zhi Fei , Tang Zhen Zhou
Published: February 2011

Laser shock processing is a technique similar to shot peening that imparts compressive residual stresses in materials for improved fatigue resistance. Finite element analysis techniques have been applied to predict the residual stresses from Laser shock processing. The purpose of this paper is to investigate of the different sheet thickness interactions on the stress distribution during the laser shock processing of 7050-T7451 aluminum alloy by using the finite element software. The results indicate that the sheet thickness has little effects on the compression stress in the depth of sheet, but great impacts on the reserve side.
Study of the Grain Refinement Technology by Electromagnetic Stirring for IN100 Superalloy Vacuum Investment Casting
Authors: Jin Wen Zhong , Zhang Wei , Li Ting Ju , Yin Guo Mao
Published: February 2011

The effects of rotating electromagnetic stirring and inoculants on the solidification structures and properties of IN100 superalloy vacuum investment casting was studied with XRD, SEM and optical microscope. The results show that by initiating the 50Hz, 150A rotating electromagnetic stirring as soon as the molten metal was poured into the mould, which was coated with inoculant CoAl2O4, the average equiaxed grain size of IN100 superalloy vacuum investment casting can be refined to 95μm and the fraction of equiaxed grains can be increased to 99 %. On condition that the grain size of K417 superalloy vacuum investment casting were refined to 95μm, the tensile properties at room temperature, the morphology of （γ＋γ′）eutectic and the morphology of dendrites can be greatly improved.
Effect of Ti Addition on the Microstructure and Mechanical Properties of Cast AZ91 Magnesium Alloy
Authors: Ai Xiu Lan , Quan Gao Feng , Yang Jun , Liu Zhao Ming
Published: February 2011

Ti addition to AZ91 alloy has been investigated with conventional casting. The microstructure and mechanical property were examined. The results show that addition of Ti with an amount of 0.1~0.5%wt resulted in a refinement of the as-cast microstructure. The morphology of β phase is changed from coarse, uneven, semi-continuous skeletal network to small, uniform, short rod-like or granular. When the content of Ti is 0.4wt%, the tensile strength and elongation go up to maximum value of 197 MPa and 6.9% respectively. Small addition of 0.2%wt Ti to AZ91 alloy predominantly forms TiAl3phase, lying in β-phases at the grain boundaries. The mechanism of mechanical properties improvement caused by Ti addition is discussed.
Numerical Simulation Study of Consumable Electrode Melting Process in Electro-Slag Remelting Ingots
Authors: Rao Lei , Hu Qi Yao , Li Xiao Long
Published: February 2011

Electro-slag remelting (ESR) is a kind of special metallurgy techniques to produce high quality alloy materials. The interface of electrode and slag is the energy entrance of entire system in the remelting process. Mathematical model of consumable electrode’s melting process has been built in this paper. Some valuable variation rules of droplet diameter, droplet forming time, melting rate and purification coefficient following melting current and slag bath depth have been studied through a series of simulation work. Based on the mechanism studying of the consumable electrode’s melting, some meaningful experience to optimize the technological parameters and improve material quality of electro slag ingot has been gotten.
Numerical Simulation of Filling and Solidification Process for Low Superheat Billet Continuous Casting
Authors: Jin Yan Juan , Cui Xiao Chao , Zhang Zhu , Lin Jin Bao , Zhang Jun Ting
Published: February 2011

In view of the process of flowing steel before the establishment of strip casting, the low superheat forced pouring continuous casting technology, i.e. the molten steel is cooled by the rotating cooling rollers, then it is forced to flow into mold, has been put forward in order to reduce superheat of liquid steel, enhance the efficiency of heat transfer and improve inner structure of billet. The filling and solidification processes of low superheat casting and submerged entry nozzle(SEN) casting are numerical simulated using fluid dynamics software. It is gained that velocity distributing diagrams, temperature distributing diagrams and solidification distribution diagrams at different time in the filling process. Influences of twin-roller cooling pouring on velocity field, temperature field and solidification are analyzed. The results show that the superheat of liquid steel is decreased and the solidification rate of liquid steel is increased by low superheat casting of twin-roller cooling process, which is favorable to improving the quality of billet and enhancing pull speed.
Optimization of the Ultrasonic Wave-Assisted Extraction Condition of Peanut Protein Isolate
Authors: Zhang Hui Cui , Tang Lin , Yang Qing Li
Published: February 2011

Ultrasonic Wave was used to assist alkali extraction and acid precipitation of peanut protein isolate from defatted peanut powder. Based on the single factor test, the response surface analysis results shows that the Ultrasonic Wave-assisted Extraction condition is: ultrasonic power 210W, ultrasonic time 30min, ultrasonic temperature 40°C ,solid to liquid ratio 1:10.7, and under this improved condition the extraction yield could reach 80.09%.
Study of Heat Transfer of Steel Solidification Process
Authors: Jin Yan , Tian Zhi Bing
Published: February 2011

Because the dynamic soft reduction of continuous casting process is based on the computation of the solidification end point, using model to simulating the steel solidificating process is more and more interesting. Especially, the influence of the heat flux to the solidification end point is needed to research thoroughly. In this paper the heat transfer model for the simulation of the solidification of steel droplet is established. The simulation reveals that the steel droplet (the radium is 7.2 mm) is solidified quickly in 4.3 seconds on water cooling copper plate, and in 3 seconds there is half of the droplet is frozen to solid. If there are materials resisting heat transfer inserted between cooling plate and liquid steel, the solidification end position would be moved to the deeper place below the shell in obvious extent, and the influence of heat flux to the ratio of mushy zone is weaker than that to solidification end point position.
Preparation of SiC-Low Chromium Cast Iron Composite Material by Cast-Infiltration
Authors: An Ning
Published: February 2011

Low-chromium cast iron as the matrix, SiC particles as reinforcement, water glass sand in ordinary dry type, no negative pressure conditions, the use made of composite diffusion agent, prepared the surface of SiC particulate reinforced steel matrix composites. The results show that: SiC particles penetrate the surface of the composite material has excellent wear resistance, with the content of SiC particles increase the wear resistance of composite cast layer increased, when the SiC particle content of 20%, the wear resistance to achieve the best good. The hardness of up to 3000HV composite layer above. Smooth casting surface roughness, dimensional accuracy is more accurate, composite layer and substrate is good.
Numerical Simulation and Technology Optimization of Rear Oil Seal Bearing Die Castings Based on ProCAST
Authors: Dong Yi , Fan Xiao Ming , Liu Bin
Published: February 2011

In production,the Φ105 mm hole of rear oil seal bearing die castings often appear porosity, shrinkage and other defects , resulting in the parts to scrap. The existing gating system design of rear oil seal bearing die castings was improved , and the flow and temperature field of the two programs that before and after improvement were analyzed by ProCAST software. The simulation results predicted the casting defects, and the conclusion was consistent with the production. By using the improved process optimization, the rejection rate of die castings can be reduced effectively. Die casting is a chipless forming of casting with high casting dimensional accuracy, high surface quality and high production efficiency [1,2]. Therefore, it has developed rapidly in the automotive, communications and other industries. However, due to shrinkage, porosity and other reasons, leading to high rejection rate of castings. With the emergence of commercial casting simulation software, the casting production has been developed from semi empirical and semi theoretical onto theorization, quantification and controllable track[3-5]. In this paper, the casting defects of rear oil seal bearing is analyzed by using numerical simulation technology[6]. By optimizing the casting process, the casting quality is improved, and the rejection rate is reduced effectively.
Clad Strip Casting Using a Twin Roll Casters
Authors: Nakamura Ryoji , Haga Toshio , Tsuge H. , Kumai S. , Watari H.
Published: February 2011

The three layers clad strip was fabricated by a vertical type tandem twin roll caster for clad strip (VTTCC). The effect of the casting conditions of the base strip and the overlay strip on the interface between the base strip and the overlay strip was investigated. The temperature of the molten metal and roll-load were investigated casting conditions. Base strip was AA8079 and overlay strip was AA6022. The proper melt temperature of the overlay strip was around the liquidus line of the base strip. The proper roll-load, which was smaller than rolling, was existed.
Thermal Deformation Prediction in Machine Tool Model by Using Transfer Functions with Time Delay
Authors: Suzumura Fumihiro , Makihara Hiromasa , Ohtani Kozo , Ikeda Masahiro , Fukushima Chiharu , Katayama Gonojo
Published: February 2011

The purpose of this paper is to estimate thermal deformation of machine tool model by using transfer function with time delay. The prediction method of thermal deformation based on frequency domain is constructed from transfer function between specified surface temperatures and the relative displacement in cutting area. The relative displacement in cutting area is predicted using two specified surface temperatures near heat source in machine tool model. As a result, the method can be predicted with enough certainty at what rate the temperature changes the most rapidly on machine's startup transient behavior. The method proposed in this paper is remarkably effective to estimate thermal deformation and confirm that the error between experimental and estimated values will be remarkably reduced.
Effect of Operated Parameters on Removal Rate and Surface Roughness in Precision Atomization Ultra-Polishing Process of Copper Surface
Authors: Li Qing Zhong , Wang Yong Guang , Guo Zhi Xue , Guo Dong Ming
Published: February 2011

Compared with the traditional chemical mechanical polishing (CMP) technique, the precision atomization ultra-polishing (PAUP) technology has the advantages of friendly environmental and damage-free. This paper established a novel PAUP tester based on the atmospheric pressure theory, and explored the possibility of PAUP technique. Furthermore, effects of operated parameters on the material removal rate and surface roughness were investigated in PAUP process. It was found that a material removal rate of 78.302 nm/min was obtained with a surface roughness of 0.015 µm at the optimal parameters. This study provides insight into the development of the novel ultra-polishing methods and its underlying theoretical foundation.
Application of PPR to Thermal Error Modeling of an INDEX-G200 Turning Center
Authors: Guo Qian Jian , He Lei , Zhu Guang Ming
Published: February 2011

Thermal errors are the major contributor to the dimensional errors of a workpiece in precision machining. Error compensation technique is a cost-effective way to reduce thermal errors. Accurate modeling of errors is a prerequisite of error compensation. In this paper, a thermal error model was proposed by using projection pursuit regression (PPR). The PPR method improves the prediction accuracy of thermal deformation in the CNC turning center.
Preparation and its Silica Wafer CMP Performance of Cationic Polyelectrolyte Modified Benzoguanamine Formaldehyde/SiO2 Composite Abrasives Slurry
Authors: Xu Xue Feng , Zhao Bin Shan , Yang Yu Zhi , Guo Quan , Peng Wei
Published: February 2011

In this paper, the adsorption characteristics of cationic polyelectrolyte PDADMAC on BGF particles and Zeta potential of BGF particles have been investigated. A new type of composite abrasive slurry was obtained with cationic polyelectrolyte modified BGF particles and its polishing performance was studied. Experimental results showed that the Zeta potential of the modified BGF particles was changed from negative to positive and the maximum value (+35mv) was obtained when the adsorption saturation was achieved, and the adsorption capacity of SiO2 abrasives on BGF particles was improved significantly as well. The material removal rate was 469nm/min with the modified BGF/ SiO2 composite abrasives slurry containing 5% SiO2 and 3% modified BGF particles, increasing by 47% and 89% than those of the unmodified BGF/SiO2 composite abrasives slurry (319nm/min) and the single silica abrasives slurry (248nm/min), respectively.
Efficiency-Reinforcement Design of Hydraulic Reciprocating Sealing Driven by Ideal Solution
Authors: Zhang Fu Ying , Zhang Hong Chao , Zheng Hui
Published: February 2011

The efficiency-reinforcement design framework of hydraulic reciprocating sealing driven by ideal solution is proposed. The seals’ main operating characteristics, seal efficiency control, leakage control and friction losses control are analyzed. The efficiency-reinforcement sealing element is designed according to TRIZ ideal final result searching strategy, sealing mechanism and tribological behavior. The computational model of efficiency-reinforcement sealing element is established with ANSYS, and its stress, strain and contact pressure distribution in different fluid pressure are also analyzed. The results demonstrated that the presented seal element outperforms the old seal in efficiency reinforcement capacity.
Shaping Principle in Hobbing and Analysis on Errors of Involute Gear Tooth Surfaces
Authors: Li Wen Long , Wei Li , He Shao Jun
Published: February 2011

An involute helical surface is one of the surfaces widely used in engineering. There are four characteristics lines ( involute, helix, straight generatrix, pathofcontact) on it. On the basis of characteristic lines, the shaping principle in hobbing is studied, the error characteristics and their interrelations are analyzed. The analysis formula of involute gear tooth surface errors is given for spur gears and helical gears.
Signal Sampling and Accuracy Analysis of Large Gear’s Angular Displacement Measuring its Deviation On-Machine
Authors: Jin Jia Qi , Li Hui
Published: February 2011

To solve the critical problem of large gear deviation on-machine: angle displacement measurement that is how to get signal acquisition and accuracy analysis of angle displacement. A new measuring method is proposed, which applies the dividing mechanism (it is composed of friction disc and circular grating) to ensure index and pick up signal of gear corner correctly and strictly according to the principle of angular displacement measurement. Furthermore, the main error which affects measurement accuracy is analyzed, and accuracy is analyzed with geometrical theory such as Fourier series and error synthesis principle etc. The experimental results indicate that angel dividing and signal samplings are easier and more efficient by the dividing mechanism, furthermore, the accuracy is in the range of total error that is permitted by verification, and the mechanism can also meet the requirement of high accuracy, so the method is significance that assessing transmission accuracy of involutes gear.
An Empirical Surface Roughness Model of Titanium Alloys Cut with Abrasive Water Jet
Authors: Zhang Shi Jin , Wu Yu Qiang , Wang Yan Li
Published: February 2011

As abrasive water jet (AWJ) started to be used in industry, especially in aerospace and automotive industries extensively, cutting precision and accuracy has become a major requirement for further application. Unlike a knife which retains a fixed shape as it cuts through material, an AWJ stream is constantly changing. It bounces back-and-forth during cutting process. As a result, a typical surface cut by AWJ displays striation marks on the cutting surface. AWJ’s cutting front can be distinguished as a smooth upper zone and a rough lower zone. As being an energy dissipation beam cutting process, the striation marks couldn’t be eliminated completely on the cutting surface. But, by selecting proper parameters, smoother surface can be generated. However, high quality also means high cost. In manufacturing process, it is desirable to produce qualified parts with the lowest cost. This paper explored all parameters which might affect surface roughness. Based on the experimental results, an empirical model has been built and tested. With this model, predicting surface roughness becomes possible before actual cutting.
Corrosion Behaviors of X80 Pipeline Steel in Different Simulated Alkaline Soil Solution
Authors: Wang Ying , Yu Hong Ying , Cheng Yuan , Shan Hai Tao , Zhang Li Xin , Sun Dong Bai
Published: February 2011

Corrosion behaviors of X80 pipeline steel were investigated in different simulated alkaline soil solution using electrochemical test, EDS coupled to SEM and weight loss method. The results showed uniform corrosion was happened on X80 steel in Shanshan and Hami simulated solution, and local corrosion was the main failure mode for X80 steel in Yumen simulated solution. The ranking of corrosion rate of X80 steel from the biggest in simulated solution was Hami, Shanshan and Yumen. With the increasing of immersion time, a dense Ca2+deposited layer was formed on the surface of X80 steel, which could inhibiting the Cl-effects on the corrosion of X80 steel in Shanshan and Hami solution. The SO42-competition absorbed effect could provide certain corrosion protection for X80 steel in Yumen solution at the early corrosion stage.
Research on the Deformation Area Materials’ Stress and Contour Surface’s Forming Mechanism of Closed Extruding Fine-Blanking
Authors: Deng Ming , Lv Lin , Wu Yu Qin
Published: February 2011

It analyzed the influence on parts’ shear surface quality by the stress and strain in the deformation area of materials. The analysis shows that the continuum linear rigid-plastic model and the fracture failure criterion in the light of damage factor, which is based on the microcosmic structure, and can accurately simulate the closed extruding fine-blanking processing; and that the higher the filling rate of outer ring is, the larger pressure stress are the deformation materials under; also that the greater the compressive stress of deformation area materials is, the higher does the deformation limit, the time of materials’ crack is delayed.
Effectiveness of Low Frequency Electromagnetic Shielding of Concrete with the Functionally Primitives Materials of Short Carbon Fibers and Graphite
Authors: Dong Fa Qin , Si Qiong
Published: February 2011

The electromagnetic shielding properties of short carbon fibers and graphite concrete were investigated, and the influence of the contents of the short carbon fibers and graphite on the electromagnetic shielding effectiveness of the concrete in low frequency was studied. The mechanism causing the influence of the short carbon fibers adulteration on the electromagnetic shielding effectiveness of the graphite concrete at low frequency was investigated. The maximum electromagnetic shielding effectiveness was up to 8.5dB in the low frequency range of 1MHz～1.8GH. The results of the investigation provide the basis for further designing and producing of high-powered electromagnetic shielding concrete at low frequency.
Research of E-Business Security Based on SOAP Protocol
Authors: Wang Yi Ran
Published: February 2011

When applied in E-Business, the technology of Web Services based on SOAP protocol can promote integration of E-commerce and distributed application. But it has some potential problems of security. Through research of technology correlated SOAP, combined with E-business safety analysis, the paper designs a kind of secure E-Business application model based on SOAP protocol. It includes SOAP secure disposal and access controller, and is realized by J2EE. The model makes the SOAP messages transmit safely and solves the secure problems of E-Business. It has great significance for popularization and application of E-commerce.
Design of a New Multi-Channel High-Low Pressure Micro-Ejection System
Authors: Yang Wei , Yin Qiang , Niu Kun Wang , Zhang Jiao , Zhang Wen Dong
Published: February 2011

According to the structural characteristics of the multi-channel high-low pressure micro-ejection system,this paper sets up mathematical model of the trajectory based on the classical trajectory theory,makes numerical analysis to prove the rationality of the structural design,tests the pressure and bullet velocity of the launching system.The results show that the analysis and design methods of the multi-channel high-low pressure micro-ejection system are reasonable and reliable.
Effects of the Copper Addition on the Precipitation of Al-Mg-Si Alloys
Authors: Yang Li Li , Jin Man , Xia Chao Feng
Published: February 2011

The effect of the copper additions on the heating process and the microstructure of 6082Al-Mg-Si alloys was investigated. The results show that there are four exothermic peaks from 50°C to 450°C in the Al-Mg-Si-0.6%Cu alloys, and the center temperature of every peak is lower than the temperature in the Al-Mg-Si alloys. Based on the observation of transmission electron microscope and three-dimensional atom probe, it is found that the copper reduce the precipitated time and the precipitated temperature of the precipitates. The number of the precipitates in the Al-Mg-Si-0.6%Cu alloys increased.
Research on Creep Fracture Mechanics Parameter by Reference Stress Method
Authors: Hu Zhao Ji , Zhang Ting
Published: February 2011

Creep fracture mechanics parameter C* is used to relate the data of Creep crack initiation (CCI) and Creep crack growth (CCG). Reference stress method (RSM) can be used to explain the result of finite element analysis on evaluating structures, and it is widely used to design and assess of general structures. The result of C* is affected by the creep coefficient A and creep exponent n for power-law creep in solving creep fracture mechanics parameter C* though using RSM.
Optimal Design of Cathode’ Working Tooth in ECM for Rifle Based Visual C++
Authors: Jia Jian Li , Zhao Wen Tao
Published: February 2011

To design an electrochemical machining (ECM) cathode for machining the mixed rifle with large spiral angle and the experiments are difficult, it takes a long period. Visual C++ was adopted to simulate the process for machining rifle as cathode moves according to the Ballistic equation. The models of 3D working tooth on cathode and the processing environment were built and the arithmetic was established. The length of working tooth was initialized. Having compared above points with design parameter, the parameter of cathode’ working tooth will be modified till it be close to design parameter. At last the result for appropriate parameter of cathode’ working tooth was proposed.
Elastic-Plastic Finite Element Simulation of Bulge Forming Process Using a Variable Cross-Section Solid Bulging Mold
Authors: Wang Ke , Wang Zhe Ying , Sun Xing Wei
Published: February 2011

Bulge forming is a novel process aimed at common products including T-branches, cross branches and angle branches. But bulging forming has not applied for two-head abnormity-shaped hollow screw rotor reported in literature. Simulation of the bulging forming of two-head abnormity-shaped hollow screw rotor has not been reported. This paper presents a simulation of the bulge forming process of two-head abnormity-shaped hollow screw rotor using a variable cross-section solid bulging mold. Some conditions including the effect of friction, boundary conditions, contact conditions and the space motion, etc are presented. The mathematical model of three-dimensional finite element analysis has been established. The distribution of generalized plastic strain and general metal flow mode in cross section of two abnormity-shaped hollow screw rotor has been analyzed. It is an effective method for the analysis of other defects and the optimization of process parameters further.
Experimental and Numerical Machining of AA 5083
Authors: Davoodi Behnam , Bagher Momeni Mohammad , Reza Eslami Mohammad
Published: February 2011

The experimental machining and finite element modeling of 2D turning of AA5083 is presented. The ABAQUS/Explicit machining simulation software is applied for the finite element modeling. The experimental orthogonal machining for were conducted to investigate the effects of various machining parameters on chip morphology, machined surface condition, and resulting cutting forces. The measured cutting forces was compared to finite element modeling results with good agreement. The effects of cutting speed and rack angle of tool cutting factor for productivity in AA5083 machining, depth of cut, on the peak tool temperature are investigated. 2D Finite Element Model (FEM) of chip formation process, set up with an Arbitrary Lagrangian-Eulerian (ALE) formulation, proposed in the software ABAQUS/Explicit .the thermo-viscoplastic behavior of the workpiece material is modeled by the Johnson-Cook (JC) constitutive law. This study explores the use of experimental and finite element modeling to study the cutting force. Results of this research help to guide the design of new cutting tool materials and coatings and the studies of chip formation to further advance the productivity of AA5083 machining.
The Influence of B2O3 on the Microstructures and Properties of CaO-B2O3-SiO2-Al2O3 Glass-Ceramics (α-Al2O3) System
Authors: Shao Hui , Zhou Hong Qing , Shen Xiao Dong
Published: February 2011

The glass composition CaO-Al2O3-B2O3-SiO2 as an alternative glass composition, and commercial α-Al2O3 as a ceramic material was used. The structure of the glass was analyzed by infrared spectra; the glass-ceramics thermal expansion coefficient was measured by dilatometer, the phase separation of the sample was investigated by scanning electron microscope and the component of phase was analyzed by X-ray. The results show that [BO3] increases and [BO4] decreases in the glass structure with the increasing of B2O3 content added into CaO-Al2O3-B2O3-SiO2 glass. The relative density and dielectric constant (εr) are considerably decreased with the addition of amount of B2O3. Excellent microwave dielectric properties of 1MHz, εr = 8.0 and tanδ=0.003 are obtained by adding 10 wt% B2O3 to glass-ceramic and sintering at 875°Cfor 30 min.
Influence of Temperature and Oxygen Pressure on the Oxidation Process for Preparing Tritium Permeation Barrier
Authors: Han Shi Lei , Lee Peng Yuan , Hou Bing Lin , Wang Shu Mao , Pan Chuan Jie , Sun Zhen Chao
Published: February 2011

In ITER D-T fuel will be used for fusion plasma. Therefore a material capable of acting as a tritium permeation barrier on stainless steel is required. It is well known that thin alumina layer can reduce the tritium permeation rate by several orders of magnitude. A technology is introduced here to form a ductile Fe/Al layer on the steel with an alumina over-layer, which consists of two main steps, hot-dip aluminizing (HDA) and subsequent oxidation process. According to the experiments that have been done, Fe-Al intermetallic layer and outer aluminum coat were formed after the HDA process. In this report, we have studied the influence of temperature and oxygen pressure on the formation of ductile phases and alumina over-layer in the oxidation treatment. At the temperature of 900°C, the brittle Fe-Al intermetallic layer and aluminum coat transformed into ductile phase (FeAl and α-Fe(Al)) and a γ-Al2O3 over-layer was formed under the oxygen pressure about 5Pa. It was found that the low pressure of environment suppressed the formation of pores or cracks as well.
Parameter Design and Result Analysis for Radial AC Hybrid Magnetic Bearing
Authors: Zhang Wei Yu , Zhu Huang Qiu , Yang Ze Bin
Published: February 2011

In this paper, a novel radial hybrid magnetic bearing is proposed, which is driven by an AC 3-phase power converter, and biased magnetic fluxes are provided by an axial magnetized permanent magnet ring. Based on the introduction of the configuration and principle of the radial AC hybrid magnetic bearing (AC HMB), the methods in parameter design and design results for the prototype are presented. The parameter design results for the prototype of the radial AC HMB are simulated by 3D electromagnetic finite element method and the simulation results show that the obtained parameter is reasonable. The manufactured prototype applying to the parameter is operated and the test results also show that the design result for the prototype is available, and the AC HMB has good dynamic and static performance.
Effect of SnO2 Modification on Permeate Flux of Α-Al2O3 Microfiltration Membrane for Treating Fe(OH)2 Suspensions
Authors: Hu Xue Bing , Zhou Jian Er , Wang Yan Xiang , Wang Yong Qing , Zhang Xiao Zheng , Larbot Andre , Persin Michel
Published: February 2011

To improve the permeate flux of ceramic membrane, commercial α-Al2O3 microfiltration membrane of 0.2 μm pore diameter was modified with SnO2 nano grains by in situ synthesis method. The permeate fluxes of the membrane for pure water and treating Fe(OH)2 suspensions were studied mainly in the paper. The results showed that the pure water stable permeate fluxes of unmodified and SnO2 modified microfiltration membranes were 0.61 m3h-1m-2 and 1.87 m3h-1m-2, respectively. When treating 1L 0.01 mol∙L-1 Fe(OH)2 suspensions, the permeate fluxes of SnO2 modified membrane was higher than that of unmodified membrane all the time and the clarified permeate was obtained. The results indicated that in situ synthesis method can be successfully used to modify α-Al2O3 microfiltration membrane with SnO2 nano grains for permeate flux increase, and the microfiltration membrane has excellent treatment effect on Fe(OH)2 suspensions. Furthermore, the enhancement mechanism of permeate flux of SnO2 modification microfiltration membrane was discussed initially.
Experimental Study on Tungsten Leaching from Cemented Carbide
Authors: Jia Xiao Ming , Lian Jian Xiao , Yang Qiao , Zhang Xiu Ling
Published: February 2011

Some rust-inhibiting additives which are wildly used in water-based metalworking fluids were mixed in several lubricants which made by oleic acid, boric acid, triethanolamine and so on to prepare the experiment used solutions in a certain concentration. The phenomenon of the metal tungsten leaching from cemented carbide in these additives was examined by immersion test and electrochemical measurement experiment. According to the value of electromotive force and the results of scanning electron microscopy (SEM) analysis, the condition of the metal tungsten leaching from cemented carbide in solutions with different additives was judged. The results show that the order in ascending of the effects of these solutions on the metal tungsten leaching from cemented carbide is sodium phosphate, sodium carbonate, triethanolamine, oleate triethanolamine ester, boric acid-oleic acid triethanolamine ester, sodium molybdate, benzotriazole and sodium nitrite.
Microstructure and Cavitation Erosion Behavior of Carbide-Based Coating Deposited by Electrical Arc Spraying
Authors: Hong Sheng , Wu Yu Ping , Sun Hong Bin , Zheng Yuan , Dai Qi Fan , He Zhi Hua , Li Gai Ye
Published: February 2011

Two different martensite stainless steel 1Cr17/Carbide-based coatings (C-1 and C-2) were prepared by electrical arc spraying technique. Microstructures of the coatings were investigated by optical microscopy (OM), X-ray diffraction (XRD), scanning election microscopy (SEM). The results show that the C-2 coating has higher hardness and finer structure than the C-1 coating. The cavitation erosion resistance was tested using a China GB6383-86 standard method in fresh water. The cavitation erosion mass loss of the C-2 coating was only 55 percent that of the C-1 coating eroded 15h, the C-2 coating has better cavitation erosion resistance.
Numerical Simulation of the Effects of Cell Size on the Mechanical Property of Microcellular Polypropylene
Authors: Gong Wei , Zhang Chun , Yu Jie , He Ying , He Li
Published: February 2011

The tensile model of foams is built using UG software and the tensile deformation processes of microcellular polypropylene foams with different cell sizes are simulated using finite element method (FEM). The effect of cell size on mechanical property is evaluated based on the microstructure of the foams. The cells with small and uniform size are in a state of plane stress, which improved effectively mechanical property of the foams. Whereas the cells with large and nonuniform size are in a state of plane strain, which leads to low mechanical property. The simulation results coincide well with experimental results.
The Experimental Study on Grinding Properties of Gas Quenching Steel Slag
Authors: Xing Hong Wei , Long Yue , Li Xiu , Li Gao Liang , Zhang Yu Zhu , Wang Shao Ning
Published: February 2011

A gas quenching process to deal with steel slag and its characteristics of the new technology was briefly introduced. The grinding characteristics, mineral phases of gas quenching steel slag and the potential economic benefits of using it as cement mixing material was studied by compared to heat-stew steel slag. The results indicated that the specific surface areas (S) and grinding times (t) of the gas quenching steel slag showed a first order exponential decay relationship. With the extension of time, the specific surface areas of heat-stew steel slag was tending to balance earlier than that of gas quenching steel slag; The energy consumption of gas quenching steel slag was much lower than that of heat-stew steel slag. Gas quenching steel slag was comprised of C2S, C3S, a certain amount of (Ca2(Al, Fe)2O5）and RO phase, but the content of RO phase was relatively low, which increased the grindability of the quenching steel slag, so that the grindability of gas quenching steel slag was much better than that of heat-stew steel slag. Gas quenching steel slag prepared for cement addictives would bring great economic benefits.
Semi-Encasing Sucrose Ester and Grafting Silkworm Pupae Protein on Polyester Fabric to Modify Polyester Fabric Surface
Authors: Zhang Gang Xian , Zeng Xi Ping , Hu Wei , Zhang Feng Xiu , Jing Ling Xiao
Published: February 2011

Wearability of polyester textile is very outstanding in chemical fabric；silkworm pupae protein has good biocompatibility. In order to make a new kind of polyester textile which not only has good wearability, but also has good biocompatibility, the polyester fibers were semi-encased with sucrose ester to endue polyester fibers with reacting hydroxyl groups, and then silkworm pupae protein was grafted on surface of polyester fiber textile with a crosslinkage compound in this study. The structure of polyester textile grafted with silkworm pupae protein were studied by SEM, X-ray diffraction and differential scanning calorimetry(DSC). The polyester fibers were enclosed by layer of materials in SEM, X-ray diffraction showed silkworm pupae protein was random coil conformation, DSC exhibited the thermal property of polyester fibers almost did not change. The wearability of polyester fabric grafted silkworm pupae protein was measured too. With the increase of grafting silkworm pupae protein rate on polyester fabric, moisture permeability of polyester fabric increased firstly and decreased a little subsequently, the moister regain increased monotonously, the cockle elasticity decreased a little, the whiteness almost did not change, and flexural stiffness increased a little.
Placement Optimization for Thermal Performance of Embedded Power Chip Microwave Modules Using BP-GA
Authors: Zhang Sheng , Wu Zhao Hua , Huang Hong Yan , Chen Pin , Bi Tang Wen
Published: February 2011

In the thermal design of Embedded Power Chip Microwave Modules, the placement of chips on substrate has a significant effect on internal temperature field, thus, influence the reliability of the modules. In this paper, Based on BP-GA, the optimization for chips placement of EPCM is achieved by corresponding optimization program. To demonstrate the effectiveness of the results, ANSYS, finite element analysis (FEA) is carried out to assess the thermal field distribution of the optimization for chips placement. The result shows that the thermal field distributions of the optimization are consistent with the FEA results. The internal highest temperature of the initial placements is 90.369°C. After optimization, the internal highest temperature is 86.128°C, the highest temperature be reduced more than 5°C. It can effectively deal with the problem about optimize the thermal placement of EPCM chips, and improves the internal thermal distribution.
Preparation and Optical Property of Mn-Doped ZnO Nanorods
Authors: Chen Chuan Sheng , Liu Tian Gui , Lin Liang Wu , Xie Xi Li , Ning Zhen Wu , Chen Xiao Hua
Published: February 2011

Mn-doped ZnO (Zn0.97Mn0.03O) nanorods were synthesized by sol-gel method combined with subsequent heat treatment. The structure and optical property of Mn-doped ZnO nanorods were studied by x-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), and fluorescence. The results of electron microscopes illuminate that the Zn0.97Mn0.03O nanorods are prepared at calcinations of 450 under the protection of nitrogen. The Zn0.97Mn0.03O nanorods are composed of small particles of size 20–30 nm. Fluorescence spectra of Zn0.97Mn0.03O nanorods exhibit that there are two very strong blue emission peaks at 451 nm and 461nm except a strong UV emission at 396 nm.
Corrosion Resistance of Al2O3-ZrO2 Composite Coating by Microarc Oxidation on 2A12 Aluminum Alloy
Authors: Li Yu Hai , Zhao Yan , Li Bao Yi
Published: February 2011

The Al2O3-ZrO2 composite ceramic coatings were prepared on 2A12 aluminum alloy by Microarc oxidation in the mixed electrolyte of 40g/L Na2SiO3 and 8g/L Na2WO4 solution containing different ZrO2 content particles. The thickness of the coatings was measured by an eddy current thickness meter. Microstructure and phase composition were analyzed by scanning election microscopy (SEM) and X-Ray diffraction (XRD), respectively. The experimental results show that ZrO2 in electrolyte can promote coatings growth; Al2O3-ZrO2 composite ceramic coatings consist of α-Al2O3, t-ZrO2, m-ZrO2, and ZrO2 is located in island-like discharge channels and does not destroy the integrity of composite coatings; There is scarcely any erosion on the surface of Al2O3-ZrO2 composite coatings because the intermediate product Zr(OH)4 could suppress composite coating corrosion.
Effect of Two-Step Deforming and Aging Process on the Properties and Microstructure of Cu-Cr-Zr-Mg-Si Alloy
Authors: Cheng Jian Yi , Yu Fang Xin , Ao Xue Wen
Published: February 2011

Effect of two-step deforming and aging process on the properties and structure of Cu-Cr-Zr-Mg-Si alloy was investigated. The results show under the condition of same cold deformation, two-step deforming and aging processes can improve overall performance of the alloy. The hardness obtained by two-step deforming and aging process is higher 6%-9% than that by single-step deforming and aging. The hardness and conductivity are up to 160HV and 88.1% IACS respectively after 80 % rolling and reaging at 480°C for 30min. The particles precipitate along the dislocation and pin on the dislocation during the reaging. These finer particles distribute more uniformly in the copper matrix and result in the higher strength and electrical conductivity.