bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Analysis and Experimental Study on Temperature Field of Brake Disc during the Air-Cooling Process
Authors: Zhang Shi Zhen , Wang Wei Rui , Jin Liang , Jiang Wei
Published: February 2011

Numerical study established by using ANSYS 12.0 has been performed by considering convective and radiative heat transfer to predict the transient thermal behavior of a brake disc during air-cooling process of heat treatment. Though the model based on the numerical study, temperature distribution maps at different time delays and variation in the temperature at different parts of the brake disc are given. Additionally, experimental results demonstrate the validity of the simulation analysis through comparing with the results obtained from the transient analysis. It is shown that the air-cooling numerical model of brake disc is verified and has the rather accurately temperature prediction ability.
Calculation and Analysis on the Key Parameters of High-Speed Linear Motor Feed System
Authors: Cheng Jun Hong
Published: February 2011

High-speed machining is playing a more important role in modern manufacturing technology. The feed system of high-speed machine tool is one of the most important components. The linear motor has been widely used in high-speed machine tool. In this paper，a kind of machine tool feed system directly driven by a linear motor is introduced，and its technical parameters are analyzed and calculated. The main parameters’ influence factors and best scope are given out.These results can offer theoretical basis for manufacturing machining technology.
Residual Stresses Distribution Calculation of the Cu-Cr-Zr Alloy Contact Wire Used in High-Speed Electrical Railway
Authors: Liu Yong , Liu Xin Long , Tian Bao Hong
Published: February 2011

According to the strain distribution test data through the rectangle bent beam test, the crack compliance method (CCM) using the Legendre polynomials as the interpolation was employed to measure the residual stresses distribution in the Cu-Cr-Zr alloy contact wire which used in high-speed electrical railway after soluted or soluted-aged-various deformation treatment. The results show that the residual stresses would release, and after soluted-aged-deformation treatment the difference of the residual stresses between the surface and the sub-surface would be dropped into a low level range about 80 MPa from 780 MPa with the same residual stresses distribution direction in the Cu-Cr-Zr alloy contact wire. The Cu-Cr-Zr alloy contact wire prepared process in four steps are as bellow: soluted at 950°C for 1 hour, pre-deformed for 40% ratio, aged at 480°C for 2 hours, and subsequent the second deformed for 75% ratio.
Study on Active Screen Plasma Carburizing of Austenitic Stainless Steel
Authors: Zheng Shao Mei , Zhao Cheng
Published: February 2011

AISI 304 austenitic stainless steel was carburized at low temperature by means of the active screen plasma carburizing (ASPC). A layer of carbon supersaturated solid solution (i.e. the Sc phase) can be formed on the surface without precipitation of chromium carbide. The hardness of the carburized steel is greatly improved without degradation of its corrosion resistance. ASPC also solves some problems associated with the conventional DC plasma carburizing (DCPC), such as temperature uniformity, edge effect and so on. Particles sputtered from the active screen were collected and analyzed. XRD and SEM analysis indicated that the sputtered particles in sub-micron scale were neutral Fe3C and Fe2C5. The particles play the role of the carbon carrier in ASPC. Therefore, ASPC is also a multi-stage process, involving sputtering, physical adsorption, desorption, diffusion and deposition, the same as active screen plasma nitriding.
Nonlinear Fitting Technology of 7-Parameter Cross-WLF Viscosity Model
Authors: Shi Xian Zhang , Huang Ming , Zhao Zhen Feng , Shen Chang Yu
Published: February 2011

Viscosity takes an important role in filling simulation in injection molding. This paper presents a computational approach to estimate the 7 parameters of Cross-WLF viscosity model based on nonlinear fitting technology. The numerical strategy is line search. Line search Newton Method is employed here since the Newton direction is the most efficient one. Test case shows its results are of high accuracy and the RMS error between fitting and experimental data is less than 10-5.
Analysis for Effect of Key Parts on Precision of High Precision Machine Center
Authors: Wang Feng Tao , Song Lu Tao , Zhang Bin
Published: February 2011

Increasing the machining precision of machine tools has imposed higher demands for dynamic characteristics of the key components. Taking the MDH50 precision machining center as a example, this paper established the flexible body of five key components, bed, column, spindle boxes, slipway and worktable, and built the rigid-flexible coupling systems of whole machine, based on the basic theory of multi-body system dynamics. Then the cutting force reference to the actual constraints was applied to the system and the dynamics simulation was carried out. The effect of every component on machining precision was effectively identified. Dynamic stiffness testing of the machine is based of principles of testing the transmission components dynamic stiffness, and further analysis of the each component dynamic stiffness is conducted, which can verify the accuracy of flexible body analysis.
Integrated Simulation of Injection Molding Process and Mold Deformation Using the Uniform Mesh
Authors: Huang Ming , Liu Chun Tai , Zhao Zhen Feng , Shen Chang Yu
Published: February 2011

For the large and complicated injection mold, the deformation of mold is one of the important factors to affect the plastic part quality and mold life. However, the accurate prediction of mold deformation is usually difficult because of the no-matching mesh between the part molding analysis and the mold structural analysis. Their analysis results can not be directly imported mutually, which leads to the loading of boundary condition having much obstacles in integrated analysis. To conquer the problem, this paper researches and develops an injection molding simulation system(Z-mold) based on Hele-shaw model, and establishes the data share interface between Z-mold and ANSYS by means of uniform mesh. Based on these studies, this paper carries out the integrated analysis of injection molding and mold. The deformation of mold under the load of the real molding pressure is successfully predicted, which is more accurate than the estimation by use of the empirical formula. This paper’s integrated study possesses great application value.
The Bifurcate Fracture Analysis of Linear Red Copper Penetrator
Authors: Gou Rui Jun , Zhang Shu Hai
Published: February 2011

Red copper has been widely used in shaped charge liner because of its good ductility. Red copper penetrator is the Linear Explosively Formed Penetrator (LEFP) with some length and energy which has been produced when linear red copper shaped charge liner is overturned under the effect of detonation production. Compared with some ordinary jets sword, it has some characteristics such as the broad range of stand-off, big cratering and obvious rear effect and may meet with many operating requirements in different environment. It has been discovered that the bifurcate fracture phenomenon of red copper penetrator will occur with the increase of stand-off when it is initiated on edge midpoint in its property test experiment, and results in the separating cratering on the target which influences its effect. The Propagation characteristics of detonation wave in explosive and the effect of detonation wave on red copper shaped charge liner are analyzed, and then the velocity change obtained by each element and the velocity relationship between each element are studied. So it can be drawn a conclusion that the velocity gradient is the main factor which results in the bifurcate fracture phenomenon of red copper penetrator. In addition, the theoretic analysis model of the bifurcate fracture in red copper penetrator is built. On the basis of modeling analysis and calculation, the criterion of the occurring bifurcate fracture and the measures avoiding the bifurcate fracture are put forward. The results agree well with that of experiments.
Investigation on the Numerical Simulation of Hot Stamping of Advanced High Strength Steels
Authors: Wang Li Min , Zhou Tian Rui , Wang Li Juan , Yang Xiao Ling
Published: February 2011

Hot stamping represents an innovative manufacturing process for forming of advanced high strength steels, implying a sheet at austenite temperature being rapidly cooled down and formed into a die at the same time (quenching). This affords the opportunity to manufacture components with complex geometric shapes, high strength and a minimum of springback which currently find applications as crash relevant components in the automotive industry. With regard to the numerical modeling of the process, the knowledge of thermal and thermo-mechanical properties of the material is required. The material model under hot stamping condition of advanced high strength steel should be set up. The Finite Element Analysis is an essential precondition for a good process design including all process parameters. This paper presents the finite element simulation of a hot stamping process and describes a number of procedures for the simulation of hot stamping. In addition, the development direction is pointed out at the end of this paper.
Fabrication of PET Fabric/Ni-Fe-B Alloy Composite through a Electroless Plating Process with a Novel Activiting Method
Authors: Liu Zheng , Zhang Jing Di , Zhou Ying Zhi
Published: February 2011

Electroless plating of Ni-Fe-B alloy on poly(ethylene terephthalate) (PET) fabrics with a novel activiting method was investigated. The activiting steps were immersion the samples to a methanol solution (10 mL) containing 2 g nickel acetate for 30 min, then immersed in an other methanol solution (10 mL) containing 1g potassium borohydride to adequate reaction. Low-cost activator was gained by potassium borohydride reduce nickel acetate on the PET fabric surface. Scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) were used to characterize morphology, structure, composition of the activated layer and Ni-Fe-B coating on the PET fabric. The results indicate that Ni-Fe-B alloy deposits by the electroless deposition were continuous and uniform.
Design of New Hydraulic Lifts for Construction Machinery Assembly
Authors: Wang Zhong Heng , Zhu Jian Gong
Published: February 2011

In this paper, according to the domestic construction machinery market，bulldozers，the representative machinery assembling with hydraulic lifts make mechanical, electrical, hydraulic innovative design. AMESim software will use for its modeling and simulation. AMESim simulation results show that the new design of the hydraulic lift is more stability and synchronization than the traditional one.
Discussion on Convergence Issues in ABAQUS/Standard while Carrying Out Damage and Fracture Analysis
Authors: Wang Huai Wen , Ji Hong Wei , Sun Ying , Miao Hui
Published: February 2011

As a universal finite element method commercial software, ABAQUS has been widely used in scientific research and engineering applications. However, convergence difficulties are familiar issues while carrying out damage and fracture analysis. Several methods, which are helpful to avoid these convergence problems, are presented in this paper. Baseline simulations about damage initiation and propagation in composites indicate that a larger value of viscous regularization causes the peak of the reaction force to be higher. A smaller viscosity parameter is better than bigger one. Other advanced techniques, include using automatic stabilization and customized general solution controls, are adoptable to improve convergence in ABAQUS/Standard analysis. The results of the paper are expected to provide guidance for the new user of ABAQUS.
Flow Features Analysis of Throttle Notches of Proportional Direct Valve
Authors: Jia Wen Hua , Yin Chen Bo , Jiang Guo Jin
Published: February 2011

Flow features, specially, flow rate, discharge coefficient and efflux angle under different operating conditions are numerically simulated, and the effects of shapes and the number of notches on them are analyzed. To simulate flow features, 3D models are developed as commercially available fluid flow models. Most construction machineries in different conditions require different actions. Thus, in order to be capable of different actions and exhibit good dynamic behavior, flow features should be achieved in designing an optimized proportional directional spool valve.
Experimental Analysis and Performance Evaluation of Fu Feng Highway Prestressed Concrete Bridge after Strengthening in China
Authors: Naser Ali Fadhil , Wang Zong Lin
Published: February 2011

Fu Feng highway prestressed concrete bridge is located in Changchun City which is the capital and largest city of Jilin province and it located in the northeast of China. The strengthening of the bridge structural members can be attempted by replacing poor quality or defective materials by better quality materials, attaching additional load-bearing materials, and re-distribution of the loading actions through imposed deformation on the structure system. The objectives of this study are to explain the strengthening process of damaged structural members of Fu Feng bridge, and to evaluate the performance of the bridge structure by adopting static load test. The strengthening process of damaged structural members includes three stages. These stages include the strengthening of box girders floor by casting of 10cm of reinforced concrete in the floor of box girder within the location of positive bending moment in the mid-span and edge span, the strengthening of box girders web by pasting steel plates in the inside of the right and left of box girders, and the strengthening of the transverse beam of piers No. 18 and No. 19 by using carbon fiber sheet. The results of static load test show that the values of testing coefficient ( ) of stress range from 0.83 to 0.92 are less than allowable value 1.05. Therefore, these values satisfy the allowable value of standard, indicating that the structural member has a certain strength reserve and the working state of the bridge structure in good state. the ratio between the measured and theoretical deflection is 1.41 and 1.68 for condition 3 more than allowable value 0.8, indicating that the state of stiffness is not good and there are still a serious shortage in stiffness of structure. Therefore, this study recommended that the bridge structural members need to re-strengthen by using other effective technical and materials to increase the stiffness of structural members of the bridge.
The Study of the Model for the Formation Process of GMAW
Authors: Li Chun Tian , Du Chang Hua , Luo Yi , Xu Hui Bin
Published: February 2011

It is based on the comprehensive analysis of welding circuit for GMAW arc power, a system model, through power, cable, wire, droplet and arc, is created, and a voltage function of wire is also developed according to distributed temperature function about a variable of genuine length of wire. Then, a dynamic and multicycle droplet- voltage mathematic model is also found by the time-weight coefficient φ for the equivalent length of transferred droplet and by the transition of wire volume from a solid to a liquid state. Besides these, a arc-voltage function, involved the welding current, the genuine length of wire and the height of welding nozzle, is established logically and especially, Meanwhile, the correlative parameters is simultaneously analyzed. At last, there made an acute and good comparison between the oscillograms of simulation and experiment for voltage and current in the paper.
Virtual Disassembly Simulation of Varying Target Component for Complex Products
Authors: Zhang Xiu Fen , Zhang Shu You , Qiu Le Miao , An Xiang Hua , Sa Ri Na
Published: February 2011

The varying target component virtual disassembly simulation technology is presented to support the disassembly analysis and feedback in product design for disassembly by a 3D visualization way. The disassembly weighted hybrid graph (DWHG) is constructed to describe the constraints and disassembly priority relationships among constituting components of product. In addition, a hierarchical recursive construction method is proposed to enable the rapid construction of DWHG for complex products. Based on the DWHG, varying target component disassembly sequences are generated by a recursive reasoning method. To facilitate the virtual disassembly simulation, the component disassembly path is translated into the discrete critical path points and the critical path point recognition technology is proposed to obtain them. The disassembly simulation of components could be controlled through the transform of pose matrix. Finally, a case study proves the validity and feasibility of the proposed method.
Tribological Performance of Fabric Composites Filled with Nano-Additive under Varied Load Conditions
Authors: Lu Ling , Yang Yu Lin , Feng Ya Ping
Published: February 2011

The hybrid Kevlar/PTFE(polytetrafluroethylene) fabric composites filled with nano-additives at the content of 1wt% of the matrix resin were fabricated. To determine the influence of the load on the tribological properties, the filled and unfilled composites sliding against AISI-1045 steel were performed on the block-on-ring wear tester under varied load condition. Scanning electron microscopy(SEM) was utilized to examine the morphology of worn surfaces of the composites and the counterparts. The results show that: the addition of nano-titania and nano-alumina can enhance the wear resistance of the composite; at the low load, the influence of load on the friction coefficient of the composite is obvious, the main wear mechanism of the composite is microcutting; with the increase of the load, the influence of the load on the wear resistance of the fabric composite becomes significant, the main wear mechanisms of the composite are plastic deformation and matrix-fiber debonding.
Numerical Simulation on Thixo-Forging of Magnesium Matrix Composite
Authors: Yan Hong , Huang Wen Xian
Published: February 2011

The thixo-forging of magnesium matrix composite was analyzed with computer numerical simulation based on rigid viscoplastic finite element method. The constitutive model of SiCp/AZ61 composite was established in our prior literature. Behavior of metal flow and temperature field were obtained. The differences between traditional forging and thixo-forging processes were analyzed. Results indicated that thixo-forging was better in filling cavity than forging. Simulation results were good agreement with experimental ones.
Test and Analysis of Friction Torque for Wind Turbine Pitch Bearing
Authors: Zhang Ming Zhu , Li Hong Tao , Zhao Hai Tao
Published: February 2011

In this paper, we introduce a new test method for friction performance of wind turbine pitch bearing. Four loading devices are used to put on load on the pitch bearing from different directions through load board. It can accurately simulate the axial force, radial force and overturning moment of wind turbine pitch bearing. The data acquisition device can measure the value of speed, torque and actual output load of loading hydraulic cylinder. After analysis and calculation, the influence of additional friction torque produced by loading device can be obviated, the friction torque of wind turbine pitch bearing under different loads can be test accurately in the laboratory. The research shows that the structure of test bed is compact, mechanical rigidity is good, the replacement of bearing model is expedient. It puts on load easily and can measure the frictional torque of wind turbine pitch bearing under different loads more accurately. It can provide data for performance analysis of wind turbine pitch bearing and ensure the pitch bearing satisfying the application requirements.
Real-Time Data-Based Fault Diagnosis System
Authors: Wang Hai
Published: February 2011

Mining from the equipment/technology process historical data can find diagnosis knowledge. Real-time analysis and evaluation on the status of equipment can be realized based on its current state parameters and historical information, which detect the potential fault rapidly and protect equipment to avoid failures further. This paper did an in-depth study in real-time data-based fault diagnosis system, built a real-time data integration platform and accomplished intelligent diagnosis method by ANFIS networks with the mined historical data. The production process was diagnosed and evaluated online with this diagnosis method. Combined with actual production system, its prototype system was developed.
Diagnosis System of Manufacturing Equipment Based on Structure-Fault Tree
Authors: Wang Hai
Published: February 2011

Paper analyzed diagnosis technologies that were applied to manufacturing equipment, and researched the unidirectional mesh data structure of the fault essence. Then the integrated diagnosis method was proposed. The method was based on structure-fault tree, which has a good capability in knowledge management and maintenance. Diagnosis knowledge representation and organization model was expatiated, at same time the integrated reasoning process was accomplished. Finally, a prototype system for the CNC machine was developed that has verified the method’s correctness and feasibility.
Test Research of Stamping Property for 500MPa Grade Super Steel Sheet
Authors: Ni Hong Qi , Zhang Jin Ping , Wang Shuqiang
Published: February 2011

Super steel has the same chemical composition as plain carbon steel, but its yield strength is higher than plain carbon steel because it has finer grain size. The products of super steel sheet have been used in automobile parts, which not only improves the quality of the automobiles, but also reduces the cost and weight of automobiles, decreases energy consumption and environmental pollution. At present, several automobile manufacturers have applied the super steel products to their parts, such as Across Beam and Longitude Beam, Automotive wheel, et al. This paper introduces the tensile test, cold bending test and metallographic examination for 500MPa grade super steel sheet that have been done. The hardening index, value of plastic strain ratio, yield strength, tensile strength, even percentage elongation and other mechanical performances have been studied. The press forming performance of 500MPa grade super steel has been analyzed too. It can be used for guidance of stamping production.
Predict and Analysis of Fold in Steering Knuckle Forging Based on Numerical Simulation
Authors: Wei Wei , Jiang Peng , Yu Guang Zhong , Cao Fei
Published: February 2011

The steering knuckle was hard to be formed because of complex shape and high quality requirement. This paper predicted fold defect in forging based on numerical simulation. The whole process was reviewed and the cause of fold and evolution was analyzed. Further more, the effect of different fillet radius as well as draft angles on fold was compared. Accordingly, the measures were presented. Finally, the process tryout was done at site. This was quite in accord with the results of simulation. As a result, the optimum analyzed technical parameters were obtained and the fold was avoided.
Processing Parameters Optimization for Stagger Spinning of Trapezoidal Inner Gear
Authors: Cheng Xiu Quan , Sun Ling Yan , Xia Qin Xiang
Published: February 2011

Spin-forming of trapezoidal inner gear is a new technology of the near-net forming in gear manufacturing field. Processing parameters, such as the initial thickness of blank and radial reductions of each roller, greatly influence the forming quality of spun part. The forming quality of trapezoidal inner gear involves the filling status of gear tooth and dimensional accuracy of root circle. An approach for processing parameter optimization of the forming quality of the trapezoidal inner gear stagger spinning is proposed. The proposed approach integrates the orthogonal experiment design, gray relational analysis, and analysis of variance (ANOVA). The experiment result indicates that the proposed approach is effective in determining the optimized processing parameters for the stagger spinning of trapezoidal inner gear.
A New Flaw Identification Model of Ultrasonic Signals Based on EMD and Possibility SVM
Authors: Zhao Xiu Fen , He Ming Ge , Yin Guo Fu
Published: February 2011

Automatic identification of flaws is very important for ultrasonic nondestructive testing and evaluation of large shafts. A novel automatic identification model of defects is presented. Empirical Model decomposition (EMD) is applied to feature extraction of ultrasonic signals, and possibility Support Vector Machine (SVM) with Dempster-Shafer (DS) theory to perform the identification task. Meanwhile, comparative study on convergent velocity and classified effect is done among SVM and artificial neural network (ANN) with DS models. To validate the method, some experiments are performed and the results show the proposed system has very high identification performance for large shafts and the possibility SVM processes better classification performance and spreading potential than ANN with DS model under the small study sample condition.
EIS Study of Molybdate Conversion Coatings Formed on AZ91D Magnesium Alloy
Authors: Wu Li Ping , Yang Zhong Dong
Published: February 2011

An environmentally friendly molybdate conversion coating based surface treatment was developed for AZ91D magnesium alloy. The EIS technique was employed to study the effects of the conversion bath composition and temperature on the corrosion protection performance of molybdate conversion coatings on AZ91D magnesium alloys. The optimum conditions under which obtained conversion coatings showed the best corrosion resistance were determined. The Nyquist results showed that the value of charge transfer resistance increased by 22.5 times for the sample treated in the optimized molybdate conversion bath.
A Single Stage Hot Forging Process of Alternator Poles
Authors: Yang Cheng , Zhao Sheng Dun , Zhang Jian Jun
Published: February 2011

Based on precision forging method, a single stage hot forging process of alternator poles is put forword, which the heated blank can be forging by only one press in a special closed die. In the last this process is verified by the software of Deform-3D which is employed rigid-plastic FEM method.
Grain Refinement in Constrained Groove Pressing of 7050 Aluminum Alloy
Authors: Dong Xiao Lei , Yun Bing , Ma Zhi Hao
Published: February 2011

Constrained groove pressing is a simple and effective method of grain refinement. Using the experimental data obtained by regression analysis, this paper analyzes the simulation of the four pass constrained groove pressing deformation of 7050 aluminum alloy. The simulation results show that the grain size of the billet is refined significantly after four pass constrained groove pressing deformation and decreases from the original 90 μm to a minimum of 14.0 μm. With the increase of the number of deformation passes, refinement effect becomes weakened gradually, the grain size tends to stabilize and the organization is more uniform.
Effect of Magnetic Field on Air Film Continuous Casting
Authors: Qu Fu , Cui Jian Zhong
Published: February 2011

The influences of low frequency magnetic field and static magnetic field on the air film casting process are studied in this paper. 6063 aluminum alloy ingot of 174-mm diameter were produced by electromagnetic air film casting process; intensity of the coil current is from 50 to 200A, and frequency is from 15 to 30Hz. The results showed that low-frequency magnetic fields can speed up the flow of liquid metal in sump and the air film stability was undermined, leading to folds and segregations appeared on the ingot surface. Static magnetic field could inhibit the melt to erosion the solidified shell effectively, it’s help to improve the speed and pull good surface quality.
The Analysis of Core Shift in Injection Mold and its Optimization Based on AMI
Authors: Guo Zhi Zhong , Li Yue , Zhao Xian Jun
Published: February 2011

Core shift is the phenomenon that the core will be shifted under the injection pressure during its molding process. Excessive core shift will bring variation in frozen-crust thickness which will lead to the buckling deformation of products and lower their structural performance. This paper takes the shell of U-disk as an example and analyzes the reasons of core shift in the injection mould designing with AMI, and its analyzed findings can be used for mould designing to shorten the developing period of products and decrease the cost of products and increase their economic benefit.
Investigation on the Elongation of Tailor Welded Blanks with Different Thickness
Authors: Tian Hao Bin , Li Zhen Lei , Deng Xiao Feng , Liu Xian Ping
Published: February 2011

Tailor welded blanks (TWBs) get popular used in the automobile for the light-weighting, and the assessments for TWBs formability are more and more important owing to the TWBs with different thicknesses. In this paper, based on the tensile test and low carbon high strength steel (ZStE220P), the influences of seam location and the length of sample on the elongation are studied, and the results shows that the location of seam has greater effect on the formability of TWBs and elongation is getting decreased with the seam shifting to the thinner part.
Fabrication and Bending Strength of Al/SiC Composites with High Volume Fraction of Reinforcement by Combining Powder Injection Molding and Pressure Infiltration
Authors: Xiong Liang , He Hao , Li Yi Min
Published: February 2011

The paper presents the result of an experimental investigation on the fabrication of Al/SiC composites with high volume fraction of SiC particles by pressure infiltration of liquid aluminum into preforms prepared by powder injection molding (PIM). To obtain the required high particle volume fraction, SiC powders with a bimodal particle size distribution were used. The influence of powder loading and particle size on the bending strength of the prepared composites has been investigated. It is demonstrated that pressure infiltration permits to achieve high relative densities for the composites (i.e. 98.8%). The microstructure studies revealed a uniform distribution of SiC particles in the composites without interface reactions between the particles and the aluminum matrix. The bending strength increases with increasing powder loading and decreasing particle size of the coarse powders in the bimodal powder system.
The Crystallization Characteristics of Carbon Nanotubes/Pb-Sn Composite Coatings
Authors: Hu Zheng Xi , Jie Xiao Hua , Lu Guo Hui
Published: February 2011

Multi-walled carbon nanotube (MWCNT)/Pb-Sn composite coatings and ordinary Pb-Sn alloy coatings were prepared by electrodeposition technique, respectively. The morphology images of the coatings in different growth time were observed by SEM at high and low magnifications. The results showed that composite coatings had a compacter and refiner surface than ordinary Pb-Sn alloy coatings; the addition of CNTs increased the number of crystal cores and changed the directions of crystal orientation, which resulted in a fine network structure.
Tool Path Design Methods for High Efficiency Die Cavity Machining with CAD/CAM Technology
Authors: Xu Dong Mei , Sheu Jinn Jong , Chang Bo Wen
Published: February 2011

In this research, high efficiency machining tool path design of die cavities were developed using CAD/CAM and plunge roughing technology. The algorithms of cutting tool path design for ideal and non-ideal rouging area were proposed to improve the material removal rate (MRR). The proposed tool path design methods are based on the minimum numbers of rectangular or triangular patterns to cover the roughing areas. The cutting results of the traditional Z-plane and the plunge roughing were compared to show the improvement of the cutting efficiency with the proposed methods. Design of experiments (DOE) method was adopted to optimize the tool path designs and cutting conditions. Cutting experiments were carried out to verify the proposed cutting path design methods. The better material removal rate was obtained using the proposed plunge roughing method compared to the traditional Z-plane roughing. Both of the cutting simulations and the cutting experiments also showed the cutting efficiency of plunge roughing is increased with increase of cutting depth. The proposed hybrid tool path design method can further improve the cutting efficiency of plunge roughing process.
The Spray Angle Improvement of Single Inlet Pressure Swirl Atomizer Using Partial Structure Modifying
Authors: Wu Ji Liang , Zhang De Yuan , Jiang Xing Gang
Published: February 2011

This paper analyzed the velocity field of the section between outlet orifice and the conical swirl chamber with a kind of single inlet pressure atomizer using CFD (Computational Fluid Dynamics) method. A method of modifying the outlet orifice position referring to the swirl chamber in order to improve the spray angle and its homogeneity is proposed. The result of the experiments shows that it is a feasible method to improve the quality of this kind of atomizer.
Application and Development of High-Efficiency Abrasive Finishing
Authors: Li Chang He , Qi Ling Yun , Zhao Hua Yang
Published: February 2011

High-efficiency abrasive machining is one of the important technology of advanced manufacture. Combined with raw and finishing machining, it can attain high removal rate like turning, milling and planning. The difficult-to-grinding materials can also be ground by means of this method with high performance. In the present paper, development status and latest progresses on high efficiency abrasive machining technologies relate to high speed and super-high speed grinding, high efficiency deep-cut grinding, hard and brittle materials high-efficiency grinding, powerful grinding and belt grinding were summarized. The efficiency and parameters range of these abrasive machining processes were compared. The key technologies of high efficiency abrasive machining, including grinding wheel, spindle and bearing, grinder, coolant supplying, installation and orientation of wheel and workpiece and safety defended, as well as intelligent monitor and NC grinding were investigated.
Optimization for Tooth Profile of Assembled Cathode Based on Comsol
Authors: Fan Zhi Jian , Shen Jian Qiang , Tang Lin , Fan Qing Ming
Published: February 2011

The working tooth of traditional cathode can’t change angle with the helix angle changing while processing mixed rifle, so the rifle would be widen and sunken. An assembled cathode comprising a cathode body and ten turntables with teeth was designed, which can do relative motion to body. The step between adjacent turntable teeth being a cause to induce cave and eddy, three schemes were adopted to optimize teeth shape and the gap flow field was simulated by COMSOL. The results show that the gap flow velocity bear on the shape of tooth, while the left side of which was chamfered (R0.24mm) and the right side screw out 0.15mm, the shape of tooth is considered appropriate. The simulation results are consistent with to the experiments.
Development of Cutting Tools with Built-in Thin Film Thermocouple for Monitoring Machining Temperature
Authors: Zeng Qi Yong , Zheng Xiao Feng , Zhang Gao Hui , Chen Le
Published: February 2011

Temperature plays a vital role in the machining industry today. NiCr/NiSi thin-film thermocouples have been deposited on the rake face of polycrystalline cubic boron nitride (PCBN) tools by magnetron sputtering. The typical deposition conditions are summarized. Static and dynamic calibrations of the NiCr/NiSi thin-film thermocouples are presented. The Seebeck coefficient of the TFTC is 37.3 μV/°C. The response time is about 3.9 ms. The testing results indicate that the developed NiCr/NiSi thin-film thermocouple sensors perform excellently when machining A3 steel in situ.
Ice Accretion of Glaze Loads Model on Wires of Power Transmission Lines
Authors: Liu Chun Cheng , Liu Jiao
Published: February 2011

In connection with the process of glaze ice, prediction models about height and thickness of ice coating under uniform and non-uniform ice accretion of wire are presented by taking into account local collision efficiency, freeze coefficient and collection coefficient based on the existing model at home and abroad. The time-dependent ice models on the conditions of different median volume diameter of super-cooled droplets, wind speed and wire diameter are analyzed. Compared with the existing model, the proposed ice accretion model performed well in predicting ice’s weight and thickness. At the same time, it can give some lights on ice disaster and anti-icing design for power transmission lines.
Ice Accretion Cause and Mechanism of Glaze on Wires of Power Transmission Lines
Authors: Liu Chun Cheng , Liu Jiao
Published: February 2011

The cause of ice accretion of transmission line and ice accretion mechanism are both summarized systematically. The mechanism of ice coating of wire caused by thermodynamics, fluid mechanics and the current electric field coupling is pointed out. In connection with the process of glaze ice, the existing models at home and abroad for the prediction of height and thickness of ice coating are summarized and analyzed, it can give some advises on further study of ice accretion prediction and some lights on ice disaster and anti-icing design for power transmission lines.
Microstructure and Mechanical Properties of Aluminum/Stainless Steel Joints Welded by Different Weld Heat Input
Authors: Zhang Hong Tao , Liu Jia Kun , Zhao Hong Yun
Published: February 2011

Dissimilar metals joints between aluminum and zinc-coated steel were joined by CMT machine with ER4043 filler metal. The microstructure and mechanical properties of the joints obtained with different heat input were analyzed. The results showed that the thickness of interfacial intermetallic compound was determined by the welding heat input. Tensile specimens were broken in HAZ of aluminum base metal and the tensile strength of the joint can reach 122.3MPa.
Analysis of the Hardness and Elastic Modulus Distribution in a High Strength Steel Welded Joint by Nanoindentation
Authors: Lan Liang Yun , Qiu Chun Lin , Zhao De Wen
Published: February 2011

Nanoindentation technique was employed to study the hardness and elastic modulus for different regions in the welded joint of high strength steel. And the variation in mechanical behavior at micro scales was analyzed combined with microstructure observation. Experimental results showed that both maximum hardness (4.11GPa) and maximum elastic modulus (210.3GPa) were obtained in the coarse grained HAZ and the corresponding microstructure was granular bainite. While the weld metal and fine grained HAZ had similar values of hardness and elastic modulus, and corresponding microstructures were acicular ferrite and polygonal ferrite respectively.
Rheological Fracture Analysis of Beam
Authors: Yang Ling Qiang , Liu Xu Cong , Shu Qing Lian
Published: February 2011

Based on the normal H-K rheology model, a new rheological model containing fracture elements for concrete or rock cracked body is introduced. The method to ascertain rheology state is put forward. The new rheological model can change to Maxwell or Kelvin model to express the instantaneous failure, delayed failure state and the accelerating segment. The researching failure element method was used to study the crack propagation. Then the cracking elements were studied using rheology mechanics to solve the cracking time. At last a case study was given to validate the method is feasible.
Research about the Effect of Ultrasonic Impact on the Fatigue Life of Butt Weld Joint of 16MnR Steel
Authors: Yu Ying Xia , He Bo Lin , Yu Huang Huang , Shi Jian Ping
Published: February 2011

Surface treatment was carried out on the butt joint weldment of 16MnR steel by using the HJ-II-type ultrasonic impact machine. The ultrasonic impact current is 1.2A, the impact amplitude is 30 microns and ultrasonic impacting time is 30min and 60 min,respectively. Fatigue experiment was carried out for both treated specimen and un-treated specimen. The fatigue fracture observed with the scanning electron microscope of 6360LA type. The experimental results show that the fatigue life of the butt joint weldment of 16MnR steel can be significantly improved through the ultrasonic impact treatment. The main reason is that the ultrasonic impact can reduces the stress concentration in the weld toe, decrease the tensile stress, and even change to compressive stress in the weldment, the grain size in the welded joint can be refined. The longer the impact time, the greater increasing range of fatigue life will be. Compared to the sample without treatment, its fatigue life was increased 375.22%, 521.24%, respectively, when the impact time was 30, 60min, respectively.
Simulation on the Thermal Behavior in Vacuum Electron Beam Welding of Magnesium Alloy
Authors: Luo Yi , Liu Jin He , Ye Hong
Published: February 2011

The thermal behavior during electron beam welding on magnesium alloy were analyzed and simulated. According to the thermal effect of the electron-beam-generated keyhole, a mathematic model of rotary Gaussian body heat source with incremental power-density-distribution was developed. This model can be useful for simulating the thermal effect of metal vapor plasma on the surface of the workpiece and the deep-penetrating effect of the electron beam. By the action of thermal model, the characteristics of temperature field during vacuum electron beam welding on AZ61 magnesium alloy were studied by the method of finite element analysis. And then, the influence of welding parameters on the temperature distributions and the weld contours were analyzed. The simulations and experiments showed that the different deep-penetration effects and temperature distributions were achieved with the varying welding energy inputs, and the metal vapor plasma has a significant impact on the weld contour of magnesium alloy.
Microstructure and Mechanical Property of (Sn-9Zn0.05Ce)xBi Solder
Authors: Du Chang Hua , Luo Yi , Su Jian , Yin Li Meng , Li Zhen Kang , Liu Bin
Published: February 2011

The (Sn-9Zn0.05Ce)xBi solders with different Bi contents were prepared by a new process. The characteristics of solders about microstructure, tensile strength, elongation and microhardness were studied. The results showed that addition Bi can induce acicular or granular Zn-rich precipitated phase in Sn-9Zn0.05Ce solder. To increasing Bi content caused more Zn-rich phase distributed disorderly. When the Bi content was added to 4%, the granular Bi precipitated phase was observable. The tensile strength and hardness of (Sn-9Zn0.05Ce)xBi solder will raise, but elongation descend significantly due to the Bi content increasing. It can be funded that there was a more obvious turning point as w(Bi)=2wt﹪.
Numerical Analysis of Controlling Welding Deformation of the Wall Plate of Large Cylindrical Structure by Pre-Stress Method
Authors: Shi Chun Yuan , Meng Qing Yuan , Jin Cheng
Published: February 2011

During the welding of the wall plate of cylindrical structure, the edges of cylinder generates obvious wave-like deformation and affects subsequent assembly. In this paper, based on the numerical simulation method, welding deformation controlling by pre-stress method is studied. The effects of the pre-stress level and the welding sequence on the final deformation are discussed. The results show that the level of pre-stress can obviously control the welding deformation of the longitudinal beams, but can not control the welding deformation of transverse beams. Using the selected welding sequence: welding transverse beams firstly, exerting pre-stress, and then welding longitudinal beams, this welding sequence can reduce the wave-like deformation after welding.
Study on the Numerical Simulation of the Resistance Spot Welding Process of Magnesium Alloy
Authors: Wang Jun , Hu Yun Yan , Wang Hui Xia , Zhang Yu Feng
Published: February 2011

Spot welding of magnesium alloy was a complex processes of thermal, electrical, mechanical and metallurgical mutual coupling, meanwhile its’ low melting point, high thermal conductivity, and high linear expansion coefficient increased the welding quality control difficultly. Basing on SYSWELD, a numerical simulation of effects of welding current, welding time, thickness of plate, electrode pressure gauge and size on the nugget shape and welding quality of ZA31B was demonstrated. The relationship between the size of the nugget dimensions and the welding parameters was established by a large number of simulation and experimental study. The experimental results showed that the analogue result was consistent with the test results, and it could be used to guide the actual production.
Mechanical Properties on the Welded Connection of Pipe and Hollow Spheres Joints
Authors: Yan Ya Jie , Lei Hong Gang , Yang Xue
Published: February 2011

Taking pipe - hollow spherical node as the object, and using ANSYS finite element analysis software, established five kinds of finite element model to analyze the stress concentration at the weld connection of the different connections of steel structures - hollow ball under the uniaxial tension. Obtained this node’s stress concentration factor, stress distribution, by changing the hollow spherical diameter and wall thickness, pipe’s diameter and wall thickness, obtained the trend of the stress concentration factor under different control ball matches. Take static tests on typical structures of two specifications 6 hollow sphere nodes, get the measured stress concentration factor, and stress distribution of this node. Through comparative analysis of theoretical analysis and experimental results, show that the two rules are consistent. The research results can provide basis for improving the pipe - hollow spherical joints connecting structural.
Prediction and Application of Welding Residual Deformation of Steel Sheets
Authors: Le Mei , Pan Zeng , Lei Li Ping
Published: February 2011

Butt laser welding experiments of Q235 sheets in different parameter conditions are conducted, and residual deformation values of the samples are measured. To predict welding deformation, heat transfer analysis is first done by FEM to obtain corresponding quasi-steady temperature data; then an equivalent model is constructed based on temperature and inherent strain theory, and bending moment values are reversely calculated through specific measured deformation values by static analysis, which are verified by a series of process experiments. In the end, the established equivalent model is applied to predict welding angular deformation of the I-beam structure. It is shown that the proposed method has a high accuracy and efficiency.
Semi-Solid Stirring Brazing of SiCp/A356 Composites and Aluminum Alloy in Air
Authors: Xu Hui Bin , Luo Quan Xiang , Li Chun Tian , Du Chang Hua
Published: February 2011

The semi-solid brazing process of SiCp/A356 composites and aluminum alloy was investigated. The two substrates were heated up to the semisolid temperature range of Zn-Al filler metal in the joint region by a resistance heating plate. At this point a stirrer was introduced into the weld seam in order to mix filler metal and the two sides of substrates into a single uniform joint. After stirring, specimens were sectioned for analysis of macro- and micro-structures along the weld region. The research shows that SiCp/A356 composites and aluminum can be successfully joining with semi-solid filler metal. It can be found that most of the oxide film on the surface of the base metal was disrupted and removed through the observation by SEM. The metallurgical bonds formed between the filler metal and the base materials. Moreover, the oxide film of surface of aluminum alloy was more thoroughly disrupted and removed than that of surface of composites with existing of Sic particle. The joint microstructure with globular α-Al grain enclosed by rich-Zn phase can be obtained after stirring brazing.