bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the Deep-Hole Honing of Cavity of Oxygen-Free Copper
Authors: Liu Zhan Feng , Feng Ya Zhou
Published: February 2011

In this paper, taking the cavity in oxygen-free copper as the object, a set of special honing head suitable for processing the cavity structure of oxygen-free copper are designed and manufactured based on the characters and grindability of materials. The experiment of honing under different grinding parameters has been done for the new honing head. Through the theoretical analysis and test, reasonable honing parameters and optimal abrasive are identified for the honing head. The results shows that the machining-process of honing the cavity of oxygen-free copper by the designed a set of special honing head is conducted smoothly and achieved the good machining effect.
Energy Consumption and Emissions Analysis of Natural Gas Exploitation
Authors: Gao You Shan , Wang Au Hong
Published: February 2011

Nowadays, remarkable immolations and charges are taking place deeply and continuously in the marketing area the enterprise brand operation is a strategic problem of operation which relates to the enterprise’s life. This article elaborated the creative meaning of the running of the business enterprise, and it emphasizes from establishing the brand operating, erecting the key of the brand operation, enhancing the key of the brand operation to carrying on the analysis of the brand value accurately and so on, in which it has a discuss about the problem of the design and the practice of the enterprise brand operation.
Acoustic Signal Recognition Based on Time Series Model
Authors: Cui Yu Quan , Shi Le Jun , Fang Yu Wei
Published: February 2011

Using time series model, isometric transformation time series model and ARTAFIT model, we deal with acoustic signal, obtaining different sets of parameters according to different acoustic signals. We use support vector machine (SVM) to recognize different acoustic signals by analyzing different sets of parameters. When the parameter set is too large, we should first reduce order making use of principal component analysis (PCA), then we can recognize them using support vector machine. In the end, we give a case study, which indicate the results of applying our models are satisfactory.
Diffusion Bonding of ZrB2 Ceramic and Al-Sn-Mg Alloys at Atmosphere
Authors: Pan Hou Hong , Iijima Keigo , Liu Yong Jun , Itoh Isao
Published: February 2011

Diffusion bonding of ZrB2 ceramic and Al-Sn-Mg alloys was carried out at atmosphere. The Al-Sn-Mg alloys were Al-xmass%Sn-ymass%Mg (x=0, 0.5, 1.0, 2.0; y=0, 0.5, 1.0, 2.0). ZrB2 ceramic was fine ZrB2 type. The bonding conditions were 873K for 3.6ks, 7.2ks and 14.4ks under the pressure of 1MPa, 2MPa and 4MPa. The microstructures of the bonding interface and the shear fracture surface were investigated by SEM and EPMA. The bonding strength was examined with the shear fracture test. The results show that ZrB2 ceramic could be joined to Al-Sn-Mg alloy with diffusion bonding. “Al-Sn” alloy can be used as an interlayer for diffusion bonding of ZrB2 ceramic. And the optimum “Al-Sn” alloy is Al-0.5Sn-0.5Mg. Shear strength of 42~44 MPa can been obtained for ZrB2/Al-0.5Sn-0.5Mg joint bonded at 873 K for 7.2 ks, 14.4 ks under 2 MPa, 4 MPa.
Study on Intelligent Analysis of the Causes of SMT Solder Joint Defects Based on Fuzzy Neural Network
Authors: Huang Chun Yue , Wei He Geng , Li Tian Ming , Yan De Jin
Published: February 2011

By determining membership function of the input parameters and selecting defuzzification method, the evaluation model which can be used to intelligent analyzing the causes of SMT solder joint defects was set up. The fuzzy neural network was trained by using the output variables of the training samples from intelligent discrimination as the input variables of training samples of fuzzy neural network. The fuzzy neural network was tested by using the output variables of the testing samples from intelligent discrimination as the input variables of testing samples of fuzzy neural network. The results show that by using the evaluation model the cause of SMT solder joint defects can be analyzed intelligently and the results of intelligently analysis are reasonable, the evaluation model can be used practically.
Inverse Analysis of Material Parameters of Multiple Foam Layers Based on Artificial Neural Network
Authors: Su Xiao Xiang , Gu Yao Dong , Finlay J.P. , Jenkinson I.D. , Ren Xue Jun
Published: February 2011

Closed cell polymeric foams are widely used in sport and medical equipments. In this study, an artificial neural network (ANN) based inverse finite element (FE) program has been developed and used to predict the nonlinear material properties of EVA foams with multiple layers. A 2-D parametric FE model was developed and validated against experimental data. Systematic data from FE simulations was used to train and validate the ANN model. The accuracy and validity of the ANN method were assessed based on both blind tests and experimental data. Results showed that the proposed artificial neural network model is robust and efficient in predicating the nonlinear parameters of foam materials.
The Effect of Complexing Agent on the Surface of Aluminum Alloy Plating Ni-P Alloy
Authors: Chang Qing Hua , Chang Zhen Zhen , Bai Yu Ting , Chen Xiao Yu , Peng Die
Published: February 2011

In this paper, the effect of different concentrations of complexing agent on the surface of aluminum alloy plating Ni-P alloys is studied. Study the influence of malic acid complexing agents on the electroless Ni-P alloy deposition rate, morphology, corrosion resistance, and determine the optimal complexing agent concentration. The results show that when the malic acid concentration is 24g /L, the deposition rate gets to maximum, and coating uniformity, structure compact and corrosion resistance is best.
Monitoring of Effect of Electrode Force on Resistance Spot Weld Quality Using Electrode Displacement Method
Authors: Wang Xian Feng , Meng Guo Xiang , Ye Qian , Liu Jian Xia , Xie Wen Hua , Feng Zheng Jin
Published: February 2011

The effect of electrode force on the weld quality of resistance spot welding monitored using electrode displacement was experimentally studied in this article. The electrode displacement was detected by the grating displacement sensor, and the maximal electrode displacement was obtained by the measurement system. The weld quality was evaluated by the tensile-shear strength of spot welds. Groups of spot welding experiments were performed under different electrode pressure, and the relationship of the maximal electrode displacement and tensile-shear strength in weld lobe was analyzed. The results showed that the relationship between electrode displacement and weld quality is not constant when the electrode force changed.
Effect of Cooling Condition on Microstructure and Mechanical Properties in Large Line Energy Welded Joints of Ultra-Fine Grained Steel
Authors: Zhao Hong Yun , Zhou Li , Chen Bo , Wang Guo Dong
Published: February 2011

The medium and heavy plate of 800 MPa grade ultra-fine grained steel was welded by CO2 gas shielded welding using large line energy. The effect of cooling condition on microstructure and mechanical properties of welded joints was investigated. The results showed that the cases about significant grain size increasing and strength decreasing do exist in the heat affected zone of large line energy welded joints of 800 MPa grade ultra-fine grained steel. Grain growth and softening in the heat affected zone could be suppressed effectively by water cooling in the course of welding. The mechanical properties of welded joints could be significantly increased by water cooling, and the process of CO2 gas shielded welding under water cooling is practical for joining ultra-fine grained steel using large line energy.
Polyhedral Oligomeric Silsesquioxane/PDMS Hybrid Coating Protecting Polyimide from Atomic Oxygen Erosion
Authors: Duo Shu Wang , Song Mi Mi , Li Ting Zhi , Luo Ying , Li Mei Shuan
Published: February 2011

Hybrid inorganic/organic polymers have been prepared by copolymerizing a silanol terminated polydimethylsiloxane (PDMS) with an Octa(aminophenyl) -silsesquioxane (POSS). The AO resistance of these POSS/PDMS hybrid films was tested in the ground-based AO simulation facility. Exposed and unexposed surfaces have been characterized by X-ray photoelectron spectroscopy. The XPS data indicate that the carbon content of the near-surface region is decreased from 65.3 to 18.9 at% after AO exposure. The oxygen and silicon concentrations in the near-surface region increase after AO exposure. The data reveal the formation of a passive inorganic SiO2 layer on the POSS/PDMS hybrid films during the AO exposure, which serves as a protective barrier preventing further degradation of the underlying polymer with increased exposure to the AO flux. The erosion yield of the POSS/PDMS (20 wt%) hybrid film was 1.7×10-26 cm3/atom, decreased by two orders of magnitude compared with the value of 3.0×10-24 cm3/atom of the polyimide film.
Study on the Legs Connection Technology of Jack-up Drilling Platform
Authors: Qin Hong De , Zhu Ya Zhou
Published: February 2011

The paper makes study on the legs connection technology of jack-up drilling platform. It analyzes the high strength and large thickness rack plate’s material characteristics, and gives the welding process for this material and notes during welding. The important technologies are the rack plate’s joint and the chord’s joint. Based on 152.4mm and 127mm thickness steel plate, this paper makes a detailed study on these two important technologies.
The Structure and Mechanical Properties of Turtle Shell and Biomimetic
Authors: Ding Xiao Fei , Jiang Ling , Liang Yan , Wu Cheng Wei
Published: February 2011

There are many types of shells in the world of biology such as various egg shells, conch shells, tortoise shells and skulls of human, all of them are one kind of thin shell structure with uniform curvature and lightsome of texture. This structure is not only light but also has a good pressure resistance. The composition, microstructure, and three-point bending properties of the turtle shell are studied in the paper. The results show that the turtle shell is composed of the element of Ca, P, C, Cl and Na etc. There are many pores in the turtle shell, and the cortical outer layer and spongy inner layer with collagen fiber winding. The middle layer with many pores absorbs energy and lower the load when acts on it. Therefore, the shell can protect the soft tissue of turtles. The multi-layer and porous structure will provide basis for design of biomimetic such as lightweight composite damping materials.
Numerical Simulation of Punching Bonding Based on AutoForm
Authors: Wang Jiang Tao , Shen Ming Qian , Xue Tao , Dai Guo Hong
Published: February 2011

Punching bonding made for study context and Autoform selected for platform, numerical simulation of stamping was carried under different shapes, different materials, different parameters, and the different simulation results was gained . And deformation, the thickness of the forming limit analysis of simulation results, etc., and thus such important parameters as the thickness of sheet metal, punch diameter, the speed and the size of power punching and etc.,was modified and debuged, the combination of optimized process parameters of sheet metal was achieved in the final. Therefore, AutoForm not only can be used to overcome the difficulties,which there is no standard available, relying on repeated experiments to determine the parameters of the connected so as to achieve green design stamping; but also be made for stamping die design and production of connections to increase the efficiency and the expansion of the stamping connections the scope of the application.
Stress Distribution of Bonded Joint with Rubbery Adhesives
Authors: He Xiao Cong
Published: February 2011

This paper deals with the stress distribution in adhesively bonded joints with rubbery adhesives. The 3-D finite element analysis (FEA) software was used to model the joint and predict the stress distribution along the whole joint. The FEA results indicated that there are stress discontinuities existing in the stress distribution within the adhesive layer and adherends at the lower interface and the upper interface of the boded section for most of the stress components. The FEA results also show that the stress field in the whole joint is dominated by the normal stresses components S11, S33 and the shear stress component S13. The features and variations of these critical stresses components are discussed.
Study on Defect of 304 Stainless Steel Industrial Condensation Board in CO2 Laser Welding
Authors: Luo Jian , Xue Ke Liang , Li Fei , Xiang J.F. , Yin D.K.
Published: February 2011

Based on the welding problems of 304 stainless steel serpentine flow industrial condensation plate, the three kinds of CO2 laser welding procedures are adopted to manufacture the condensation plate. The optical microscope, SEM, EDS, micro-hardness and tensile tests are used to analyze the microstructure and micro-hardness of 304 stainless steel sheet joint. The relationships between the generated defects and carbide separation in the welding joint are discussed. Due to the grain refinement, the micro-hardness of welding seam is increased. Therefore, it is reasonable factors that the heat input, cooling velocity and temperature gradient to improve the defects of 304 stainless steel serpentine flowing channel industrial condensation board in CO2 laser welding.
Effects of Ultrasonic Power on Bonding Strength of Anisotropic Conductive Film Joint in Chip-on-Glass Assembly
Authors: Lin Yong Cheng , Jin Hao , Fang Xiao Nan , Zhang Jun
Published: February 2011

Polymer-based anisotropic conductive film has become widely used in many electronic packaging interconnect applications. In this study, thermosonic flip chip bonding technology for anisotropic conductive film (ACF) joints of chip-on-glass (COG) assembly is investigated. The effects of ultrasonic power on the curing degree and bonding strength of anisotropic conductive film joints are discussed. The results show that (1) The bonding strength of the ACF joints firstly increases and then fast decreases when the ultrasonic power is continuously increased; (2) The curing degree of ACF material increases with the increase of the ultrasonic power. When the ultrasonic power is 3.52W, the curing degree of ACF material can reach 94.1%; (3) The optimized value of ultrasonic power is 3.5W for the studied assembly.
The Effect of NaOH on the Surface of Magnesium Alloy Ni-B Alloy Plating Properties
Authors: Chang Qing Hua , Chang Zhen Zhen , Bai Yu Ting , Chen Xiao Yu , Peng Die
Published: February 2011

In this paper, the effect of different concentrations of sodium hydroxide on the surface of magnesium alloy plating Ni-B alloys is studied. Focuse on the influence of different NaOH concentrations on electroless plating Ni-B alloy plating rate, coating morphology, and composition. Ascertain the optimal concentration of NaOH. The results showed that when the sodium hydroxide concentration is 50g / L, the deposition rate is the maximum, coating uniformity, structure compact, and boron content in the coating is the maximum.
Fabrication of Fuel Reforming Catalytic Coatings for Hydrogen Production by Cold Spray Technology
Authors: Wang Feng , Wang Guo Qiang , Zhou Jing , Zhou Xin Jing
Published: February 2011

Commercial catalyst of CuO/ZnO/Al2O3 was used as feedstock to coating fabrication for hydrogen production through fuel reforming on aluminum plate. Microstructure and micro-region composition of the coatings were analyzed by SEM and EDX. It was found that the composition of feedstock and coating was basically the same; Bonding between the particles in the coating and the bonding between the coating and substrate was mainly belonged to mechanical bite and physical bonding; At low heating temperature in spraying, the coating presented applanation loosen cascade state of porous structure; Morphology of the coating influenced by heating temperature and fracture character of the particles; Methanol steam reforming reaction on the coating confirmed that cold spray technology can be successfully applied to fabrication of catalytic coating material.
Vertical Vibration of Pile Groups in Soil Described by Fractional Derivative Viscoelastic Model
Authors: Sun Jiu Min , Liu Lin Chao , Yan Qi Fang
Published: February 2011

The stress-strain relationship of soil is described by fractional derivative viscoelastic model, and established the vertical governing equations of viscoelastic soil. The stiffness and damping of the soil layer described by fractional viscoelastic model are obtained based on the method of layer. The pile-soil dynamic interaction is modeled by Winkler dynamic elastic-damping model, the pile to pile dynamic interaction and vertical vibration of the pile groups in the soil described by fractional derivative viscoelastic model is solved. The influence of the pile spacing, order of fractional derivative and model parameter of soil on the vertical dynamic impedance of pile groups is also investigated. The result indicated that the curves of the dynamic impedance varying with frequency were more complex with the increase of pile spacing, the influence of the order of fractional derivative on vertical dynamic impedance of pile groups is different at lower frequency and high frequency, and the selection of the constitutive model of viscoelastic soil had great effect on the vertical dynamic impedance of pile groups.
Temperature’s Effection to Electroplating Ni-SiC Plating on Aluminum Alloy
Authors: Chen Yan Fang , Chen Chun Mei , Jie Ya Fei , Meng Long , Sheng Jun Hao
Published: February 2011

This study is of aluminum alloy electroplating process temperature alloy electroplating Ni-SiC properties. Research shows that the results show that, when the bath temperature for 50, plating coating uniform structure, compact, the best performance, coating and maximum SiC content.
The Effect of Plate-Plate Butt Welding Stress Distribution on the Welding Deformation
Authors: Yuan Tao , Luo Zhen , Luo Hui
Published: February 2011

In this paper, the distribution of residual stress is measured which is 60mm away from the weld center with the three-dimensional magnetic measurement apparatus of HZ-21. The stress distribution of plate - plate butt welding and its influence on welding deformation are studied. The results show that, plate - plate butt of Q235B steels, the welding stress distribution of σx direction is in the direction of a curve along the seam; 24 hours after welding, the welding angular deformation increases due to the changes of welding stress, while welding angular deformation also changes the stress distribution.
Influences of Latent Heat and Butt Gap on Temperature Field and Melting Pool Shape in Laser Brazing of Beryllium
Authors: Shi Ping An
Published: February 2011

With considering the geometry characteristic of laser brazing and analyzing the action features of heat source in laser brazing, an adaptive heat source mode is constructed to simulate the dynamic response of temperature field and flow field of beryllium irradiated by a moving laser. And the shape of fusion zone and thermal cycle curve calculated agree well with the experimental results, it indicate that the proposed model is appropriate and adaptive in simulating the dynamic response of melting pool. Further, influences of latent heat of fusion and butt gap on temperature field and melting pool shape is analyzed by means of the method of numerical Analysis. The results show that the effects of the latent heat are not negligible. In particular, the influence of the latent heat is more violent under moving laser beam action than under stationary laser beam. And the predicted profile of melting pool which taking butt gap into account is more close to that of experimental results.
The Effect of the Welding Thermal Cycle on Heat Affected Zone Hardening for 500MPa Grade Screw Thread Steel
Authors: Fang Jun Fei , Yang Lei , Yuan Xiao Min , He Yi Zhu
Published: February 2011

The hardening behavior of the welding heat affected zone (HAZ) with different heat input for 500MPa grade screw thread steel is investigated in this paper. The single welding thermal cycle was applied to the test steel by a Gleeble-3500 thermal simulator. With the definition of hardness ratio, relative hardness factor and partial hardness zone, the HAZ Max hardness, hardness distribution and hardness mechanism of steel were analyzed. The results show that the HAZ hardness is always higher than the base steel hardness. The hardness ratio is increasing with the heat input decreased. The distribution of relative hardness factor of HAZ can be expressed by the Avrami equation which can describe the distribution of HAZ hardness. The width of partial hardness zone increases rapidly with the heat input increased. But at a certain degree of heat input, the width of partial hardness decreases slightly. The microstructure generated by heat input is the intrinsic factor of the HAZ hardness variation. The HAZ hardness enhances as the martensite content increases. On the contrary the HAZ hardness reduces as the ferrite content enhance on condition the heat input increase or the observed area is far away from the HAZ.
Prediction and Control of Welding Distortion in "U" Rib Orthotropic Plate
Authors: Zhou Hong Bin , Zhu Qing Ju , Liu Yun , Dong Jun Ying
Published: February 2011

Prediction and control of welding distortion is an important stage to guarantee manufacturing quality of steel structures. Thermo-elasto-plastic finite element method is employed to analyze the model of "U" rib orthotropic plate. Through this method, inherent strain in the weld zone is extracted. Inherent strain obtained which is regarded as known conditions is put on the weld zone of "U" rib orthotropic plate. Elastic finite element analysis is employed to predict the welding distortion of the plate. According to the prediction result, control scheme of welding distortion is made and a curvilinear equation is provided. The equation elaborates the shape of the welding jig controlling welding distortion. Numerical simulation method is applied to analyze the control scheme and the steps of the method are given. The numerical simulation result meets the quality request of welding deformation control. The method provides important reference for the control of the welding distortion in complex components.
Effect of Linear Cutting on Corrosion Behaviors in 304 Stainless Steel
Authors: Dong Jian Tao , Luo Zhen , Xia Da Hai , Wang Rui
Published: February 2011

The corrosion behaviors of 304 stainless steel (304SS) which has been cut and 304SS which has not been cut in two different solutions were investigated using polarization curve and electrochemical impedance spectroscopy (EIS) methods. The results show that 304SS which has been cut and 304SS which has not been cut have the similar corrosion voltage in two different solutions. However, the corrosion velocity of 304SS which has been cut is more than 304SS which has not been cut both in the two solutions and the corrosion behaviors of two 304SS in the water solution are better than in the water which has little oil.
Resistance Microwelding of Au/Ni-Plated Phosphor Bronze Sheet to Insulated Cu Wire
Authors: Mo Bing Hua , Guo Zhong Ning , Li Yuan Bo , Wang Guan
Published: February 2011

Resistance microwelding of Au/Ni-plated phosphor bronze sheet to insulated Cu wire have been investigated using mechanical testing, optical microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The results show that mechanisms of joint formation involve solid-state bonding with Au and Cu atoms diffusion at low welding current, a combination of brazing and solid-state bonding at high welding current. Due to the hindrance of Ni plating which has a higher melting temperature and hardness, the joint breaking force is smaller than that without plating.
Investigation on Joining Method Replacement for Vehicle Body’s Assembly
Authors: Lin Jian , Zhong Yi , Lei Yong Ping
Published: February 2011

Various joining methods (i.e., spot welding, arc welding, laser beam welding) have been used for vehicle body assembly. However it is unclear for the equivalent conversion of various joints which has the equivalent joint strength for the vehicle body, such as weld-bonded joint, SPR joint, which have been considered likely to replace RSW in the area of high strength steel’s joining. In order for the flexible design in the auto line of vehicles body’s joining, the equivalent (strength) weld pitch design method for various joints, including the joining of similar and dissimilar materials, is presented in this work. And some primary simulating results are presented and discussed. It is shown that the conversion method for various joints can be established based on the joint’s shear failure criteria. And the conversion results can be influenced by the sheet gage obviously. The failure criteria of various joint still need further investigation based on the simulating and experimental results.
Desirability-Based Performance Optimization of Wear-Resistant Coatings by HVOF Sprayed WC-Co Experiments
Authors: Jean Ming Der , Yang Yih Hwang , Chien Tzu Hsuan
Published: February 2011

This study presented the desirability function based on Taguchi designed experiments to solve multiple responses statistical optimal problems for the tungsten carbide/cobalt (WC-Co) coatings of high-velocity-oxygen-fuel (HVOF) processes. The eight control factors based on L18 arrays were conducted and the multi-responses of wear-resistant coatings such as hardness, deposited thickness and wear rate were evaluated simultaneously in the desirability-based experiments. Based on desirability analysis, the optimal settings have been identified, and the impacts of control factors are determined by analysis of variance on the multi-responses. Further, a confirmation run was conducted to validate the tests. Experimental results have shown that the hardness increased by 16.61% and the deposited thickness improved by 10.50%, while the wear rate decreased by 34.03%. It was clear that confirmation tests are greatly improved by way of the desirability-based multi-responses on HVOF WC-Co experiments, and these findings achieved the desired values on wear-resistant coatings. The proposed procedure was applied at HVOF sprayed WC-Co experiments, and the implementation results demonstrated its feasibility and effectiveness to maximize hardness, make a target of deposited thickness value and minimize wear rate by a HVOF.
Development and Analysis of Robust Anti-Wear Design of a-C:Zr Films by Taguchi Methods
Authors: Huang Wesley , Chen Ching Jyi , Jean Ming Der
Published: February 2011

Amorphous carbon (a:C-H) coatings with high hardness and low friction coefficient are widely applied in die and mold industries. Zirconium-containing a:C-H (a-C:Zr) coatings with double interlayered Zr/ZrC were deposited by unbalanced magnetron sputtering system. A L18 orthogonal array experiment was designed to investigate the effect of process parameter on the friction coefficient of deposited films. Control factors, such as methane flow rate, bias voltage, sputtering frequency, zirconium target current and work distance were schematized for experiments. The experimental results show that zirconium target current exhibits about 45% percent contribution in analysis of variance, and the friction coefficient of a-C:Zr coatings range from 0.13 to 0.31. From effect plots, the optimum parameters are bias voltage at -70V, zirconium target current at 0.6 A, pulse frequency at 90 kHz, methane flow rate at 6 sccm and work distance at 15 cm. The friction coefficient performs as 0.106 in verification experiments. Meanwhile, one-by-one factorial experiments were also carried out and discussed in this study.
The Effect of Heat Treatment on Mechanical Properties of Pulsed Nd:YAG Welded Thin Ti6Al4V
Authors: Fan Yu , Shipway Philip H. , Tansley Geoff D. , Xu Jie
Published: February 2011

Pulsed Nd:YAG has been adopted successfully in welding process of thin (0.7 mm) Ti6Al4V. Laser welding of such thin sheet requires a small focal spot, good laser beam quality and fast travel speed, since too much heat generation can cause distortion for thin sheet weld. The microstructures of Ti6Al4V were complex and strongly affected the mechanical properties. These structures include: α´ martensite, metastable β, Widmanstätten, bimodal, lamellar and equiaxed microstructure. Bimodal and Widmanstätten structures exhibit a good-balance between strength and ductility. The microstructure of pulsed Nd:YAG welded Ti6Al4V was primarily α´ martensite, which showed the lowest ductility but not significantly high strength. A heat treatment at 950 followed by furnace cooling can transform the microstructure in the weld from α´ martensite structure into Widmanstätten structure.
The Experimental Analysis of Modifier on Fluid Magnetic Abrasivetool
Authors: Zhang Hong , Peng Peng
Published: February 2011

Fluid magnetic abrasivetool is a kind of suspension, which is composed of soft magnetic particles, surfactants, base liquid and so on so forth, so it can have strong magnetorheological characteristics and grinding characteristics. The stability of magnetorheological fluid is one of the most important indicator to evaluate the quality of magnetorheological fluid. Sodium hexametaphosphate and PAA have perfect function to maintain dispersionstability and retrogradation, adding nano-silica can improve the retrogradation of magnetic abrasivetool, which can modify redispersibility of magnetic abrasivetool.
Experiment and Simulation of TC4 Alloy Rods Subject to Laser Shock Processing
Authors: Chen Rui Fang , Chen Yu Xiao , Hua Yin Qun
Published: February 2011

In order to improve the fatigue strength of TC4, Nd:Glass pulse laser was used to impact the surface of cylindrical specimens, X-ray stress analyzer was used to test the residual stress distribution of treated area, the laser shock processing on different ratio (η) between the diameter of specimens and laser spot were simulated with ANSYS at the same time. The numerical simulation results were well agreement with experimental data. The results indicate that the different η mainly affect residual stress distribution along the circumferential direction. Contrarily, it has few effects on longitudinal direction and in-depth direction.
Experimental Investigation on Laser Pretreatment of Optical Films
Authors: Xia Zhi Lin
Published: February 2011

Optical films have been prepared on K9 glass by electronic beam evaporation. Parameters of S-polarized Nd: YAG laser used for pretreatment and damage tests are: wavelength is 355nm, pulse width is 8ns, and incidence angle is 33.75 degree. The results reflect that: the influence of laser pretreatment on laser induced damage threshold of films is uncertain. Laser pretreatment not always improve the laser induced damage threshold of films, and sometimes it will cause negative influence. As for damage probability, for a certain testing energy density, there is an energy density scope, pretreatment pulse with energy density in which can reduce the laser induced damage probability of films. The energy density of laser pretreatment pulse should be selected according to the serving conditions of films.
Research on Defects of Titanium Alloy Laser Rapid Forming
Authors: Shang Xiao Feng , Wang Zhi Jian , Han Dong Xue , Xie Zhen Tao
Published: February 2011

In the process of metal powder laser rapid forming, various defects may be caused in forming parts on account of technical parameters, equipment performance, material characteristics and other factors. While dimensional accuracy error and surface sticky powder caused by powder factor are the two major defects of forming parts. The experimental analysis finds that less or over accumulation resulting from powder feed delay is the main reason for affecting the dimensional accuracy of cladding and the main reason which affects the appearance of surface sticky powder is specific energy.
Characteristics of CO2 Laser Welded TRIP Steel Sheet
Authors: Wang Wen Quan , Huang Shi Ming , You Qun , Kang Chung Yun
Published: February 2011

Characteristics of CO2 laser welded 1000 MPa grade Transformation Induced Plasticity steel plate were investigated under different welding power, welding speed and shield gas. Decreasing welding power, increasing welding speed or using mixed shield gas (Ar+He) all reduced the porosity in the weld metal (WM). The weld metal and HAZ near the WM had maximum hardness. In tensile strength test of load perpendicular to the weld axis, the specimens had same tensile properties as that of the raw material. For the load parallel with the weld axis, the specimens prepared with Ar had equal yield strength (YS) and tensile strength (TS) to that of the raw material. But the elongation was lower than that of the raw material. The specimens prepared with shield gas He had higher YS, TS and lower elongation compared with that of the raw material. The welded joint had lower formability than that of the raw material. The formability of specimens prepared with low welding power or mixed shield gas Ar+He was improved compared with that of the specimens prepared using high power or single shield gas Ar.
The Effect of Casting Speed on Sump Shape and Ingot Surface of HDC Casting 7075 Aluminum Alloy Ingot
Authors: Zhu Qing Feng , Zhao Zhi Hao , Wang Xiang Jie , Cui Jian Zhong
Published: February 2011

7075 aluminum alloy ingot with the diameter of 100 mm has been produced by horizontal direct chill casting in different casting speed. The effect of casting speed on the sump profile and the ingot surface quality was studied by sump profile observation. It was found that increasing the casting speed results in the deepening of the liquid pool, the adding of segregation knots and the reducing of cold shouts in the ingot surface. It is also found that the depth of the liquid pool is directly proportional to the casting speed and the squared radius of the ingot.
Effects of Low Frequency Electromagnetic Field on Segregation Layer during Hot-Top Casting of Aluminium Alloy
Authors: Wang Xiang Jie , Cui Jian Zhong , Zhang Hai Tao , Jiang Hui Xue , Wang Gao Song
Published: February 2011

Surface segregation layer are frequently encountered during aluminium alloy direct chill casting process, and the removal of the surface segregation layer before further processing of the ingot decreases the ingot yield. In this work, the low frequency electromagnetic field was applied to study the effects of low frequency electromagnetic field on segregation layer during the direct chill casting process. The results show that under the effect of the low frequency electromagnetic field, the surface quality of ingot is improved, the structure of the ingot is refined, and the thickness of segregation layer is decreased.
Prepartion of Semisolid AM60 Alloy by Novel Self-Inoculation Method
Authors: Li Yuan Dong , Xing Bo , Ma Ying , Chen Ti Jun , Hao Yuan
Published: February 2011

A research focus on semi-solid metal processing is the preparation of semi-solid slurry with non-dendritic microstructure. During the past several decades, people tended to obtain the non-dendritic structure by stirring melt of alloy which downs to the semi-solid temperature range, such as mechanical stirring and electromagnetic stirring; In recent years, with the technological innovation of semi-solid slurry preparation turned to be more convenient and efficient, most of these processes are based on the control of nucleation and growth process of primary phase during solidification, such as NRC, SSR, SLC, SEED, and CRP. In this paper, a novel process, named as “Self-Inoculation Method (SIM)”, has been proposed for semi-solid slurry preparation. The process involves self-inoculants addition to the melt, and then pouring the melt to mould through a multi-stream mixed cooling channel. The melt was avoided chemical pollution due to the particles of self-inoculants from the same composition as the melt. The semi-solid billets of AM60 alloy with non-dendritic structure were prepared by SIM. The effects of process parameters on the microstructure and the mechanism on refinement of alloy were investigated. The results indicate that pouring temperature, addition amount of self-inoculants and slope angle of the cooling channel are key factors for SIM process. The optimized parameters for the billet preparation of AM60 alloy are obtained: pouring temperature is at 680°C~700°C；addition of self-inoculants are between 5%~7% (mass fraction)；slope angle of the cooling channel is at 30°~45°. The heterogeneous nucleation was enhanced as the addition of self-inoculants; the formation of chill crystal and the fragmentation of dendrites because of cooling and shearing of the cooling channel, resulting in the increase of grains density and a small grain size.
A Physical Explanation of Plateau in Velocity vs. Undercooling Curve Using a Undercooled Dendrite Growth Model
Authors: Chen Zheng , Liu Feng , Shen Cheng Jin
Published: February 2011

A steady-state non-equilibrium dendrite growth model was extended for binary alloy assuming non-linear liquidus and solidus. Satisfactory agreement of the model prediction with the experimental data of Ni-0.7at.%B and Ni30Cu70 alloys was achieved. The velocity plateau as experimentally observed in the velocity versus undercooling is quantitatively analyzed in terms of this model. Accordingly, the initiating point (i.e. corresponding to the critical velocity of absolute solutal stability VC*) and the ending point (i.e. corresponding to the velocity of maximal tip radius VRm) of the plateau are characterized.
Preparation and Characterization of Self-Dispersal Nanometer Carbon Black Pigment
Authors: Yang Xin Yu , Wang Zhao Lun , Pan Ming Chu
Published: February 2011

The surfaces of carbon black were modified by nitric acid oxidation. The surface structures of the original and oxidized carbon black were investigated by means of FT-IR and XPS, respectively. Furthermore, the oxidized carbon black and distilled water were mixed to form the self-dispersal nanometer carbon black pigment. The particle size distribution and dispersion stability of the carbon black pigment were investigated by means of particle-size analyzer and spectrometer, respectively. The results showed that some highly marked hydrophilic character functional groups on carbon black surfaces were increased greatly by nitric acid oxidation.
Kiss-Point Position Control of Solidification Layer and Process Optimization for Twin-Roll Casting of Magnesium Alloys
Authors: Weng Wen Ping , Deng Kang , Ren Zhong Ming , Chen Qi , Chi Zhi Dong , Zhao Qi Te
Published: February 2011

The solidification and process optimization for twin-roll casting of magnesium alloys have been studied. Effects of roll speed, roller diameter, setback length and strip thickness on the position of the solidification front and the surface quality of strip were analyzed through experiments. A kiss-point model which considers the strip thickness, set-back length and roll speed was established to optimize process and enhance the surface quality of magnesium alloy strip. Results showed that the twin-roll casting process could be effectively stabilized and optimized under the direction of the model, and the defectless magnesium alloy strip was obtained.
Defects Analysis and Improvement for Electricmotorcar Aluminum Alloy Wheel by Gravity Casting
Authors: Wang Fei Fei , Sui Yan Wei , Ren Yao Jian , Zhao Xin , Sun Zhi
Published: February 2011

Analysis the electricmotorcar aluminum wheels’ hole defect on macroscopic and microscopic, observed that the main defects、concentrated site and the main alloy phase. Combined with the local casting technological parameters, the filling and solidification process of aluminium alloy hub was simulated by using Anycasting software. The results showed that: castings filling smoothly, at the junction of the spoke and the rim and the hub central are easy to produce casting defects. Using the optimized process parameters that is lower pouring temperature, higher pouring height and set the vent to experiment, after comparing the results with the original process known, Shrinkage and porosity defects decreased, but there are still some degree of defects, indicating optimized process parameters have some effect.
Effect of Cooling Rate on Microstructure and Properties of Heat-Treated Fe3Al Intermetallics
Authors: Li Ya Min , Liu Hong Jun , Hao Yuan
Published: February 2011

The casting Fe3Al intermetallics were solidified in sodium silicate sand mould and permanent mould respectively to get different cooling rates. After heat treatment (1000°С/15 h homogenizing annealing + furnace cooling followed by 600°С/1 h tempering + oil quenching), the microstructure and properties of Fe3Al intermetallics were investigated. The results show that the heat-treated Fe3Al intermetallics at higher cooling rate has finer grained microstructure than lower cooling rate, and the lattice distortion increases due to the higher solid solubility of the elements Cr and B at higher cooling rate. The tensile strength and hardness of the Fe3Al intermetallics at higher cooling rate are slightly higher also. However, the impact power of intermetallics at higher cooling rate is 67.5% higher than that at lower cooling rate, and the impact fracture mode is also transformed from intercrystalline fracture at lower cooling rate to intercrystallin+transcrystalline mixed fracture at higher cooling rate.
Structural Reinforced Parts for Improving Roof Crush Performance
Authors: Yang Ming , Liang Xi Feng
Published: February 2011

As part of a strategy for reducing the risk of rollover crashes and the significant injuries resulting from those crashes the National Highway Traffic Safety Administration (NHTSA) is proposing changes to its former roof crush standard (FMVSS 216). This paper provides an overview of the substantial benefits of utilizing structural reinforce parts as a cost-effective means of significantly improving roof crush performance. In the past several years structural reinforced parts have gone through the transformation from interesting concept to viable alternative for the improvement of vehicle structures. Finally, this paper will introduce study investigated the utilization of these types of products as both a stand-alone solution and as part of a “hybrid” solution coupled with traditional metal solutions.
The Study on Numerical Simulation of Tailor Welded Blanks on Square Cup Stamping
Authors: Qiu Xiao Gang
Published: February 2011

The stamping process of the tailor welded blank(TWB) was simulated by the software of DYNAFORM. The finite element model of a boxy part was founded, and the forming of different thickness and properties of the material was studied. Meanwhile, the influence of weld seam on forming result was analyzed. The results show that the weld seam model which founded by real properties can describe the plastic deformation and strain distribution more exactly in the forming process.
Analyzing Age Hardening Behaviors of an Al-Si-Mg Cast Alloy
Authors: Zhou Ying , Wang Gui Qing
Published: February 2011

The age hardening process for permanent mold samples of Al-7Si-0.3Mg cast alloy has been investigated by hardness measurement, differential scanning calorimetry (DSC), transmission electron microscope (TEM) and electron probe micro analyzer (EPMA). Age hardening results show that the age hardening response of Al-7Si-0.3Mg alloy is independent on cooling rate. There is a hardness value decrease about 10 HV after T4 treatment. Hardness value after as-cast aging at 150 °C for 20 h is just a little smaller than that after T6 treatment for permanent mold samples. The precipitation behaviors during T6 treatment and as cast aging treatment have been analyzed by DSC analyses. The hardness measurement results have been discussed by analyzing the precipitation behaviors and the Mg and Si concentration in α (Al).
Microstructure Changes and Computer Simulation of K4169 Superalloy Using Chemical Grain Refinement Casting
Authors: Liu Han Wu , Li Nan , Tian Qiao Nan , Dong De Chao
Published: February 2011

As an important aeronautical assembly materials, such as aeronautical gas turbine and turbine plate et al, K4169 alloy has enough high ability of resistance to high temperature deformation and a long low-period fatigue life when working, and its grain structure should be equiaxed dendrite as fine as possible in casting. Chemical grain refinement method was used to refine K4169 alloy to satisfy the demands mentioned above. By using new intermetallic compound grain refiners, chemical grain refinement casting technology was carried out to refine K4169 superalloy. The results show that the grain morphology has been transformed from dendrite to granulation, the average principal axis length of the primary dendrites has been shorted and the segregation ratios of main alloy elements mitigate with the decrease of grain size in fine-grained castings, which indicates the remarkable effects of grain refinement. In addition, basing on the model of equiaxed dendrite growth solute diffusion, continuous nucleation model, dendrite tip growth kinetics model and cellular automata (CA) technique to coupled simulate the grain structure formation process of K4169 alloy in chemical grain refinement casting, which agreed very well with experiments results, this will do much contribution to the theoretic base for studying high temperature mechanics performance and performance of resistance to corrosion of K4169 superalloy.
Soft UV-Imprinting Using Gasbag Pressure Mechanism for Side-Direction and Non-Planar Substrate
Authors: Cheng Fang Sung , Nian Shih Chih
Published: February 2011

This paper reports a gasbag pressure (GBP) mechanism for soft UV-imprinting. With this mechanism, the pressure distribution over the whole non-planar surface is uniform. In addition, the curved surface and side-direction imprinting also can be achieved. The mechanism employs a gasbag inside a closed chamber, which upon inflation compresses the whole PDMS mold/substrate stack not only from the surface but also from all the sides. The microstructures on the PDMS mold are then replicated onto photoresist coated substrates. The result shows that the pressure mechanism can provide uniform pressure for imprinting. It also provides that fine patterns with good dimensional stability can be replicated with high fidelity from soft mold to photoresist on substrates. The accuracy of replication, even at the edge, has been experimentally verified.
A New Method of Making Grating - Etched by SPM
Authors: Zhang Ying Tang , Yu Hua Wa , Wang Qiu Ping , Zhou Guang Xi , Wu Jun Fang
Published: February 2011

The original grating is etched by using the nanometer etching function of Scanning Probe Microscopy (SPM). There are five grooves etched on the surface of polymer material. The grating constant is 796.87 nm, so the fringe density is 1254 lp/mm. Diffraction pattern of the original grating is obtained on Michelson interferometer. A new method of making original grating is found. Since the Nominal Tip Radius of Curvature (NTRC) of Etched Silicon Probe (ESP) of used Veeco SPM is 5-10 nm, the etching grating should have fringe density of 50 000 -100 000 lp/mm.
Preparation and Characterization of Al2O3/ZrO2-MgO-CeO2 Composite Coatings Prepared by Flame Spraying
Authors: Zhao Wen Guang , Zhi Xin , An Sheng Li
Published: February 2011

In the present work, ultra-fine Al2O3/ZrO2-MgO-CeO2powders were used as the starting materials to produce Al2O3-ZrO2composite coatings on 45# carbon steel by flame spray. The ultra-fine Al2O3/ZrO2-MgO-CeO2powders were prepared via the co-precipitation method accompanied a crushing sintering process. The microstructure, the phase compositions and the bond strength of the crushed sintered powders and the corresponding composite coatings were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and a tensile bond strength tests respectively. It was found that the phase composition, the surface topography and the coating adhesion were different from the difference kinds of coatings. Results indicated that the phase composition of the flame sprayed ceramic coatings consisted of tetragonal-ZrO2, cubic-ZrO2, ZTA (zirconia toughened alumina) and γ-Al2O3, with a small amount of α-Al2O3, and that bond strength values attained 45.1 MPa for 42.6wt.% Al2O3/57.4wt.% Mg0.13Ce0.1Zr0.77O1.87coating.