bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Study of the Critical Process Parameters of Machining of Stainless Steels Using the Taguchi Approach
Authors: Saeedy Sina , Givi M.K. Besharati
Published: February 2011

High strength, high ductility and low thermal conductivity cause the austenitic stainless steels to be hard materials to machine so that heat concentrates at the tool cutting edge due to their properties. This study aims to optimize turning parameters of AISA 304 stainless steel. Turning tests have been performed in three different feed rates (0.2, 0.3, 0.4 mm/rev) at the cutting speeds of 120, 160 and 200 m/min. An analysis of variance (ANOVA) has been made to determine the effects of each parameter on the tool wear and the surface roughness using the Taguchi approach. It is being inferred that cutting speed has the main influence on the flank wear and as it increases to 200 m/min, the flank wear decreases. The feed rate has the most important influence on the surface roughness and as it decreases, the surface roughness decreases as well.
Research on the Vibration Tapping Performance of Particle Reinforced Aluminum Matrix Composites
Authors: Lu Hui Min , Zhang De Yuan , Liu Yang
Published: February 2011

The vibration tapping technology has been employed with success on some difficult-to-machine material such as titanium alloy, hardened steel and so on. However, there are very few studies on the application of the torsion vibration tapping in particle reinforced aluminum. The tapping performance of small size thread holes in particle reinforced aluminum matrix composites Al2O3p/Al and SiCp/Al during common tapping and low-frequency vibration tapping using high speed steal(HSS) machine-used taps is researched experimentally in this work. The influence of vibration parameters, e.g. cutting speed V, net forward angle of each stroke LT and times of repeat cutting Q on tapping torque, tool wear, tool life and quality of thread holes is investigated during the experimentation. The results show that the common vibration tapping with small amplitude, relatively high frequency and a lot of repeat cutting times suit to tap the Al2O3p/Al, whereas the step vibration tapping with large amplitude, relatively low frequency and a few repeat cutting times suit to tap the SiCp/Al due to difference performance of the two kinds of material. The influence of Q and LT on the quality of thread holes, tapping torque and tool life is sensitive on the Al2O3p/Al, whereas the influence of V and Q on the quality of thread holes, tool wear and tool life is sensitive on the SiCp/Al. Furthermore, the optimum vibration parameter in the Al2O3p/Al by dry cutting is cutting speed of 400r/min, net forward angle of each stroke of 1.5°, backward angle of each stroke of 45°. The optimum vibration parameter in SiCp/Al by dry cutting is cutting speed of 220r/min, net forward angle of each stroke of 420°, backward angle of each stroke of 430°. From the test results and micrographs, it was observed that the particle could be fractured on the surface finish on tapping processing. The proper vibration tapping parameter can void the adhesion in the tap flute, decrease the tapping torque, improve the quality of thread hole and prolong the tap life.
High Temperature Erosion Behavior of Mo-Si-Ni-Al Metal-Ceramic Composite Cladding Layer Produced by TIG Welding
Authors: Zheng Chao , Liu Zong De , Zhao Li Ping , Wang Yong Tian
Published: February 2011

In this paper, the Mo-Si-Ni-Al metal-ceramic composite cladding layer on the surface of the 304 stainless steel was applied by using tungsten inert gas (TIG) method. The phase composition and microstructure of the cladding layer were characterized by XRD, SEM and EDS. With the high temperature erosion experiment in the range of 873-1073 K, the erosion behavior of the Mo-Si-Ni-Al cladding layer was studied. The maximum total mass loss was observed in the specimen, which was tested at 923 K and 45°erosion angle. The high temperature erosion mechanism of the Mo-Si-Ni-Al cladding layer was discussed.
Wear of Uncoated HSS Tools in Drilling Difficult-to-Machine Materials with Water Vapor as Coolant and Lubricant
Authors: Wu Jian , Han Rong Di
Published: February 2011

Drilling is a semi-enclosed cutting process. Drilling of difficult-to-machine materials generates thermal/frictional damage at the cutting edges of drill bit and decreases the life. In this paper, a new cooling and lubricating technique in drilling difficult-to-machine materials is developed to improve the life of drill bit. For this study, a water vapor generator and feeding system is developed. Comparative experiments are performed for various difficult-to-machine materials under the conditions of oil water emulsion, water vapor as coolant and lubricant and dry drilling, respectively. The effectiveness of water vapor on the basis of drill bit wear is studied. Experimental results show that with water vapor as coolant and lubricant the flank wear is reduced by 45-80% and 10-15% in comparison with dry drilling and oil water emulsion, respectively.
Study on the Size Shrinking and Shape Changing of Solid-State Nanopores
Authors: Liu Li Ping , Wu Hong Wen , Xuan Yang , Wang Xiao Juan , Zhang Yan , Chen Yi Wen , Liu Quan Jun
Published: February 2011

Nanopores etched in the solid-state membranes have become the hotpot of nanotechnology research. Various methods for fabricating solid-state nanopores have been developed and reported, but the fabrication of nanopore is also a difficult challenge. In this paper, we milled nanopores of different sizes in the free-stand and low-stress solid-state membranes. And then the area around nanopores were scanned with the diffused ion beam, we found that the sediment around will melt and the shape of the nanopore becomes circular.
Study of Flux on Wetting Behavior of Sn-Zn Lead-Free Solders
Authors: Liu Huan , Xue Feng , Zhou Jian
Published: February 2011

The effects of fluxes with different activators (sebacic acid and diethylamine hydrochlcoride) on the wetting behavior of Sn-Zn lead-free solders were investigated. The wettability tests showed that fluxes with the addition of single sebacic acid or diethylamine hydrochlcoride significantly improved wettability of Sn-Zn solder on Cu substrate. However, fluxes with combined additions of above activators promoted wetting performance of the solder further. Thermal analysis (thermal-gravimetry analyzer and differential scanning calorimeter) results demonstrated that the effective temperature range of diethylamine hydrochlcoride is higher than that of sebacic acid. So diethylamine hydrochlcoride could react with oxides on the solder and substrate surfaces at a wider temperature range which resulted in an enhanced spreading of solders. Scanning electron microscopy (SEM) image showed that two kinds of diffusion layers were formed between Sn-Zn solder and Cu substrate, indicating fluxes with binary activators markedly improved welding quality of Sn-Zn solder.
Influence of Friction Stir Welding Process on the Weld Formation and Tensile Strength of Titanium and Aluminum Dissimilar Alloys Welded Joint
Authors: Chen Yu Hua , Wei Peng , Ni Quan , Ke Li Ming
Published: February 2011

Titanium alloy TC1 and Aluminum alloy LF6 were jointed by friction stir welding (FSW), and the influence of process parameters on formation of weld surface, cross-section morphology and tensile strength were studied. The results show that, Titanium and Aluminum dissimilar alloy is difficult to be joined by FSW, and some defects such as cracks and grooves are easy to occur. When the rotational speed of stir head(n) is 750r/min and 950r/min, the welding speed(v) is 118mm/min or 150mm/min, a good formation of weld surface can be obtained, but the bonding of titanium/aluminum interface in the cross-section of weld joint is bad when n is 750r/min which results in a low strength joint. When n is 950r/min and v is 118mm/min，the strength of the FSW joint of Titanium/Aluminum dissimilar materials is 131MPa which is the highest．
The Thinking of Using Multimedia Technology to Improve the Quality of Mathematics Teaching
Authors: Fan Hong Yun
Published: February 2011

Modern educational technology is widely used in college, modern educational technology application develop from simple slideshows, projection to the multimedia and network teaching, long-range education teaching, ect. The application of multimedia and network technology have positive significance in the teaching reform of cultivating student's quality , and skill training, and the creative thinking ability . Modern multimedia educational technology university plays an important role in promoting the level of teaching work and improving the quality of the education. The process of education and teaching which implements the mathematics education teaching through the application of modern educational technology curriculum, can improve math courses and teaching quality effectively. This paper explores the truth than using the modern education technology to improve education quality of teaching mathematics course. To realize mathematics teaching from the optimization, and extensive mathematics curriculum multimedia teaching, and explore the new mathematics curriculum teaching network technology actively, this paper discussed the application of multimedia technology to improve education in modern mathematics curriculum teaching quality.
Enhancement of Load-Carrying Capacity of Undermatching Butt Joints by Weld Shape Design
Authors: Zhao Zhi Li , Wang Tao , Fang Hong Yuan , Yang Jian Guo
Published: February 2011

A new attempt is proposed to improve the load-carrying capacity of high strength steel undermatching butt welded joints by shape design. Based on the principle that reasonable geometric parameters designs of welded joints can regulate the distribution of stress and strain, reduce the stress concentration factors in low strength weld zone, the geometric parameters of undermatching butt joints, such as weld toe radius, height of excess weld metal and width of the cover passes are designed. A series of tests were completed to investigate the effect of weld shape design on the mechanical properties and security of undermatching butt joints. The results showed that the critical crack sizes of the 0.6~1.0 undermatching joints is greater than or equal to the one of base metal, the joints strengths approach to the tensile strength of base mental, and the fatigue strength is far higher than that of the as-welded equalmatching butt joints.
Innovation for Joining by Forming of Magnesium Alloy Based on TRIZ
Authors: Han Shan Ling , Lv Qian Dong , Yang Lei , Zeng Qing Liang
Published: February 2011

Joining by forming of magnesium alloy is a kind of high-efficient joining method, but it’s restricted because of the limited formability of magnesium alloy at room temperature. According to the present status of joining by forming of magnesium alloy, the relative proposing solutions by using the contradiction matrix of TRIZ are given. The practice shows that dieless clinching solution is effective, and then the improvement program which also can decrease the pre-heating time considerably is presented. After analyzing, the result shows that the program is feasible.
Application and Research on Corrosion and Scale Inhibitor WJF-6 in Seawater Circulation Cooling Water
Authors: Zhou Yong Zhang , Yang Chun Yan , Ni Xin , Chen Dong Sheng
Published: February 2011

The inhibition effect of corrosion and scale inhibitor WJF-6 on Q235 steel in simulated seawater circulation cooling water was studied by rotary coupon corrosion tests. And corrosion mechanism of this inhibitor was researched by some electrochemical measurements such as polarized curves and linear polarization, scale inhibition performance of this inhibitor was studied by static anti-scale method. At the same time, the corrosion and scaling influence of concentrated 1,2,3times for corrosion and scale inhibitor WJF-6, used in simulated seawater circulation cooling water, was researched. The results showed that the corrosion inhibitor efficiency reached 91.8% with 75mg/L of the inhibitor with linear velocity of 0.3m/s, and rotation of 72h at 50°C when concentrated multiple was three times. The results of linear polarization showed polarized resistance greatly increase by adding 75mg/L of this kind of inhibitor, its inhibition rate achieved 81.3%. The results of polarized curve revealed the strong polarized area of polarized curve have left shift and anodic polarized curves of electrode reaction was increased in strong polarized area, the basic function of corrosion and scale inhibitor WJF-6 is that the anodic process of electrode reaction were restrained. The effect of concentration multiple on corrosion and scale inhibitor WJF-6 in simulated seawater circulation cooling water showed that the corrosion rate was less than 0.125mm/a of the national standard and when concentrated multiple of simulated seawater circulation cooling water exceeded three times, and scale inhibition rate was more than 90%.
Study on Nonlinear Multiple Regression Modeling of Nugget Morphology for Unequal-Thickness Dissimilar Steel Welding
Authors: Luo Yi , Du Chang Hua , Li Chun Tian , Liu Jin He
Published: February 2011

The special thermal effect makes some alterations to nugget morphology during resistance spot welding on unequal-thickness dissimilar steel. Method of nonlinear multiple orthogonal regression assembling design was introduced to design the experiment and investigate the resistance spot welding process. The indexes studied in experiments were nugget diameter and nugget deviation, which were the primary factors affecting the nugget morphology. Furthermore, four process parameters, namely welding current, electrode force, welding current duration and heat-treatment pulse current, and interactions among them were considered as the factors impacting the indexes. The nonlinear multiple regression models about nugget morphology parameters were developed on the basis of optimization. The experimental results showed that there was an effective prediction on nugget size based on the optimized models. The optimization to welding process also can be realized by the analysis to the effects of parameters and interactions.
Quality Estimation of the Resistance Spot Welding Based on Hopfield Network
Authors: Zhang Hong Jie , Hou Yan Yan
Published: February 2011

Lots of dynamic information, which can directly or indirectly reflect the quality of welded spot, is included within the electrode displacement signal of resistance spot welding process. In this research, the displacement signal is monitored and mapped into a 15×25 element bipolarized matrix by means of some method of fuzzy theory. Some welded spots are classified into five classes according to the prototype pattern matrixes. An effective RSW quality estimation system is developed based on Hopfield network when taking the tensile shear strength of the welded spot joint as the estimation index of welded spot quality. The results of cross-validation test shows that the Hopfield network can satisfactorily accomplish the task of classification of the welded spot and has board application prospects.
Formation and Growth of Intermetallic Compound Layers at Interface of Solder/Copper Alloys for Lead Frame
Authors: Huang Fu Xiang , Yin Ping , Li Chun Tian , Li Ji Chao
Published: February 2011

The effect of chemical species of copper alloys on growth of intermetallic compounds (IMCs) at interface of solder/copper alloys for lead frame was investigated. The results have revealed that Cu is the main diffusing species during aging. After aged at 160°C for 300h, only a Cu6Sn5IMC layer is observed at SnPb/copper alloys interfaces. The growth rate of IMC on the Cu-Cr-Zr system alloys and Cu-Ni-Si alloys was much slower than that of IMC on the C19400 alloy. The Pb phase and voids were found to be inside the Cu6Sn5phase. Chromium, one of the alloying element in Cu-Cr-Zr-Zn alloys, has found to be segregated at the interface between the copper alloy/Cu6Sn5. Zn and Zr in the Cu-Cr-Zr-Zn system alloy are enriched in small amout inside the IMC. These observed results were discussed and analysed on the baisis of diffusion and growth kinetics.
Quasi-Static Analysis of Beam Described by Fractional Derivative Kelvin Viscoelastic Model under Lateral Load
Authors: Yao Qing Zhao , Liu Lin Chao , Yan Qi Fang
Published: February 2011

The beam is assumed to obey a three-dimensional viscoelastic fractional derivative constitutive relations, the mathematical model and governing equations of the quasi-static and dynamical behavior of a viscoelastic Euler-Bernoulli beam are established, the quasi-static mechanical behavior of Euler-Bernoulli beam described by fractional derivative model is investigated, and the analytical solution is obtained by considering the properties of the Laplace transform of Mittag-Leffler function and the properties of fractional derivative. The result indicate that the quasi-static mechanical behavior of Euler-Bernoulli beam described by fractional derivative viscoelastic model can reduced to the cases of classic viscoelastic and elastic, the order of fractional derivative has great effect on the quasi-static mechanical behavior of Euler-Bernoulli beam.
3-D Finite Element Analysis on a Fillet Weld Sealing Joint in the High-Pressure Hydrogenation Heat Exchanger
Authors: Lu Xiao Feng , Zhao Cui
Published: February 2011

Based on the finite element analysis software ABAQUS, a sequentially coupled fillet welding thermal-stress calculation program was developed to simulate the plate close welding structure. The welding temperature fields and the stress/strain distributions of plate sealing joint of the hydrogenation heat exchanger were obtained. The simulation results showed that there existed higher stress near the fillet weld sealing joint zone and the maximum stress at the start welding point, the plastic strain of the weld joint was lager and a strain mutation occurred on the weld overlay .The analysis of the calculation result provides theory references for controlling the welding residual stress and it’s of great significance to improve the reliability and safety of hydrogenation heat exchanger.
Solid-State Dye-Sensitized Solar Cells Based on ZnO Nanorod Arrays by Low-Temperature Chemical Bath Deposition
Authors: Lee Yi Mu , Lai Chun Hung , Chen Yuan Tsu , Cai Min Hua , Liou Shin Yi , Zheng Min Ren , Lin Jenn Sen , Yang Shi Wen
Published: February 2011

A low-temperature controllable chemical bath deposition (CBD) method was demonstrated to prepare ZnO nanorod arrays. Our deposition technique includes the seeding and subsequent main CBD growth. The uniform growth ZnO nanorod arrays on the condensed ZnO seeding layer could be controlled by changing the processing parameters. Experiment results reveal that the ZnO nanorod arrays prepared under 0.03-0.05 M concentration with reaction temperature of 95 °C demonstrate the well-aligned orientation and optimum optical properties with high aspect ratio of ~21. The n-ZnO/p-NiO heterojunction electrode shows excellent rectifying behavior with extremely low leakage current. After the sensitization with N719, it is found that the degree of orientation and aspect ratio value play critical roles in the photovoltaic properties of solid-state dye-sensitized solar cells (SS-DSSCs).
Research of Thermal Anchor Attachment for ITER Magnet Supports
Authors: Pan Chuan Jie , Lee Peng Yuan , Hou Bing Lin , Sun Zhen Chao , Han Shi Lei , Pei Yin Yin , Long Wei Ming
Published: February 2011

Thermal anchor is one of the key components in ITER magnet supports to maintain the low temperature for superconductor coils. The sufficient attachment of the cooling pipe to the support plates is needed to minimize the risk of helium leakage. Brazing is one of the best choices. Three kinds of special brazing filler, including SnPb brazing filler, Ag-based and Cu-based brazing filler, were developed, which have good thermal conductivity, and toughness for brazing connection of SS 316LN at both room temperature and 77K environment. Some brazing technologies, including induction brazing, vaccum brazing, fire brazing, and arc brazing, have being investigated.
Manual Self-Propagating High-Temperature Synthesis Welding of 45 Steel
Authors: Li Zhi Zun , Xin Wen Tong , Wu Yong Sheng , Qu Li Feng
Published: February 2011

A new style of emergency welding, named manual SHS welding ,was introduced. By this technique, metal materials could be welded on the condition of no electricity, no gas and no equipments. In this paper, the mechanism of manual SHS welding has been illustrated, the effect of thermit on welding and the microstructure of the welded joint have been studied, and the mechanical properties have been tested. Results showed that the combustion velocity of the combustion welding rod became higher when the content of (CuO+Al) thermit increased. The suitable (CuO+Al) content is 60%wt ~80%wt. The tested 45 steel plates were one-side welded with back formation. Microstructure analysis indicated that there are three zones in the welded joint, which are heat affected zone, fusion zone and weld metal. The weld metal and the 45 steel plates were combined metallurgically. The weld metal was copper based alloy. EDS patterns showed that there was diffusion of Cu, Fe and Ni in the three zones. The fracture of the weld joint is a typical ductile fracture. The tensile strength of the joints reached 400MPa and the impact absorbed energy was about 35J, which meet the requirement of mechanical properties for emergency welding. Manual SHS welding is an effective welding method for emergency maintenance in battlefield and outside field.
A Welding Method for Carbon Nanotubes to Metal
Authors: Zhang Jian Wu , Luo Zhen , Li Ya Li , Zhu Jing Dong
Published: February 2011

A simple ultrasonic welding method was employed to bond the carbon nanotubes and metal electrodes, at the same time, macro-body carbon nanotubes was tried in the experimental. By the welding head exert suitable pressure on carbon nanotubes bridge on electrodes with frequency of 60 kHz and power of 1.8w, contact would be achieved between these, moreover, the image of SEM show that the bonding was tightly.
The Effects of Grit Particle Size on Frictional Characteristics of Automotive Braking System
Authors: Abdul Hamid Mohd Kameil , Stachowiak Gwidon W.
Published: February 2011

The effect of grit particle size on frictional characteristics was investigated using a vertically oriented brake test rig. Silica sand of grit sizes 50-180 µm, 180-355 µm and 355-500 µm were used in drag mode application. Results showed that the presence of hard particles from environment can influence the friction response significantly. Basically, once the hard particles enter the gap, the value and amplitude of friction coefficient tend to decrease. However, slight increase in friction with smaller particles was recorded due to more hard particles involved in mixing and changing the effective contact area. Better friction stability was related to the presence of smaller grit particles and compacted wear debris to form frictional film on the braking interface.
Resistance Spot Welding between Aluminum Alloy and Low-Carbon Steel
Authors: Qiu Ran Feng , Yu Hua , Shi Hong Xin , Zhang Ke Ke , Iwamoto Chihiro , Satonaka Shinobu
Published: February 2011

Aluminum alloy A5052 and low-carbon steel (SPCC) was welded using resistance spot welding with a cover plate. The interfacial microstructure was observed using electron microscopy. A thick two-layered reaction layer contains Fe2Al5 and FeAl3was observed at the welding interface, respectively. Mechanical property analysis suggested that the reaction layer has no effect on the tensile shear strength of the A5052/SPCC joint and affects the cross tension strength of the joint.
Effects of Thermo-Mechanical Control Process on the Microstructure and Properties of the Welded Joints of ERW OCTG
Authors: Bi Zong Yue , Wang Jun , Jing Xiao Tian
Published: February 2011

In the paper, the effects of thermo-mechanical control process on microstructure and properties of oil country tubular goods by electrical resistance welding are analyzed. The TMCP parameters are optimized by Gleeble-1500 thermo-mechanical simulator, and industrial trial is carried out. The microstructures in the welded joints of original ERW OCTG are mainly composed of proeutectoid ferrite, pearlite and widmanstatten. In contrast, the welded joints of ERW OCTG treated by TMCP consist only of refined ferrite and pearlite. The higher low-temperature impact toughness and the better resistance to the grooving corrosion of the welded joints of ERW OCTG treated by TMCP could be attributed to removing welding residual stresses, homogenizing microstructure, eliminating porosity and refining grain. TMCP facilitates the performance optimization of welded joints so that the quality of the finished product can be improved.
Research and Numerical Simulation of Contactor of High-Frequency Welding Device
Authors: Zhao Da Xing , Zhao Zhi Ming , Zhang Zheng Kun , Dai Xin
Published: February 2011

Based on the production line technology of high-frequency welding H-beam steel, a High-frequency welding device which could be used in a H-beam less than 100mm steel was designed in this work. After virtual prototype established and kinematics Simulation was carried by Solidworks and Cosmos/motion respectively, the trajectory of contact terminal was defined. And the optimal vee angle, high frequency and some other technological parameter were determined through Ansys software, which provides important reference for the design of high-frequency welding H-beam steel.
Study of the Effect of Active Fluxes in Gas Tungsten Arc Welding
Authors: Hao Jian , Luo Zhen , Bu Xian Zheng , Zhang Jian Wu
Published: February 2011

In order to investigate the effect of active fluxes on weld penetration, angular distortion and weld morphology in gas tungsten arc welding (GTAW), three types of oxide fluxes-CaO, TiO2and Al2O3-were used in the welding of 5mm think stainless steel plates. Those powders were applied through a thin layer of the flux to produce a bead on plate welds. The results showed that compared with conventional TIG welding, increased weld penetration and reduced angular distortion of the weld piece were obtained with the application of active fluxes. However, the weld morphology was not changed significantly when the powders were coated on the surface of steel. It was also found that each of the powders has a fittest range in penetration increment. Whether the rate of the coating run out of the range, the effects of these active fluxes on the increased weld penetration were not obvious. The CaO flux has a narrow effective range for deep penetration, while the Al2O3powder does have no effect on A-TIG penetration. The mechanism of those different performances has not been found out. According to the investment, the mechanism of active fluxes for the increased weld penetration and reduced angular distortion is related to the contraction of the arc.
Study on the Influence of Reduction in Area on Fatigue Life of Bearing Steel Using Statistics of Extreme Values
Authors: Chung Ho Hua , Hsu Chin Chuan
Published: February 2011

The maximum nonmetallic inclusion size and type of bearing steel has been analyzed using statistics of extreme values (SEV) in this study, and the influence of reduction in area on the maximum nonmetallic inclusion size and the fatigue life of bearing steel have been discussed as well. Scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) are used to measure the inclusion size and identify the inclusion type respectively. By adopting the criterion of return period (T) at 200, a serial analysis shows that with increasing the reduction in area of steel, the predicted inclusion size for √area max is decreasing, and the fatigue life is prolonging. This results from the defragment of hard inclusion during rolling process, and the decrease of concentration of stress around the inclusion.
Design of Hi3510-Based Embedded Wireless Video Monitoring System
Authors: Yan Ying Zhan , Peng Ling , Huang Song Fa
Published: February 2011

To meet the needs of video monitoring applications, the paper researches and designs of Hi3510-based embedded wireless video monitoring systems.The systems uses H.264 for video data encoding, combining Hi3510 encoding API to adjust H.264 rate control dynamically. Based on real-time transmission control RTP / RTCP protocol, in order to achieve adaptability and guarantee the QoS of the real-time transmission, this paper presents variable constant growth and change constant reduction method to adjust the transmission speed dynamically. In addition, this paper processes the packet loss during transmission processing, trying to ensure the I-frame reliable transmission. To transplant DWL-G122 wireless network card, it can realize communication.
Study on Effectiveness of Releasing Weld Residual Stress by Ultrasonic Impact Method
Authors: Zhang Qiu Ling , Xiao Guang Hong , Liu Xiao Yu
Published: February 2011

This paper presents the test of ultrasonic impact for reducing the welding residual stress. Three full-scale specimens according to the anchor connection plate of main girder with cable of the Jiangjin Yangtze River Bridge are made and the ultrasonic impact test are taken in laboratory to study the effectiveness of reducing welding residual stress. The comparison of welding residual stress before ultrasonic impact with the stress after ultrasonic impact is conducted and the results from test show that the welding residual stress can significantly be reduced over 50% by ultrasonic impact method and even some stress in weld could be changed form tensile stress into compressive stress after ultrasonic impact.
Modeling Weld Formation Mechanism of Automated Submerged Horizontal Position Arc Welding
Authors: Gao Zhi Guo , Jing Yi , Yu Yan , Cheng Ding Fu
Published: February 2011

An 3D mathematical model was established to illustrate weld pool development in the ASHPW (Automated Submerged Horizontal Position Welding) process. This model takes into consideration the spatial position characteristic of ASHPW, and used the heat transfer and mass transfer phenomena during welding process to explain the weld geometry mechanism in order to correctly design the bevel geometry. The final results show that the predicted geometry , such as the weld cross-section, weld width and weld cross section area, are in good agreement with experimental measurements.
Reconstruction of Human Skeleton Model Based on Selective Laser Sintering
Authors: Wang Peng Cheng , Li De Qun , Zhao Jin Long , Zhen Zhi Yan , Yan Liang Ming
Published: February 2011

Based on CT data of the lesion of an orthopedic patient with knee, Mimics13.1, Magics9.5 can be used for the medical image processing. The CT image data were filtered, interpolated, sharpen, the interest region was extracted by the application of threshold segmentation method and was grown. The three dimension model of patient’s skeleton is reconstructed. Based on selective laser sintering, the digit model of patient’s skeleton reconstructed can be accurately transformed into the object model of the individual matching skeleton. The results indicated that the contour of reconstructed knee-joint bone object model were very coincident, and symmetric with knee-joint bone defect.
Effects of Powder Characteristics on Selective Laser Melting of 316L Stainless Steel Powder
Authors: Zhang Sheng , Wei Qing Song , Lin Guang Ke , Zhao Xiao , Shi Yu Sheng
Published: February 2011

316L stainless steel parts were manufactured via selective laser melting . This work stu- dies the effects of powder characteristics such as particle size and particle shape composition on the density. It shows that the powder with a broad size distribution and using spherical fine powder can lead to an increase in the density of the loose powder and thus the densification of the laser melted powder. The aerosol powder forms parts of lower oxygen content well, and the density can reach to 90%.
Study the Application of Laser Welding in the Automotive Transmission Parts
Authors: Chen Guo Liang
Published: February 2011

Laser beam of high energy density, melting of the workpiece material welded together, can make the heating affected area and change shape minimum, without the use of flux or for dissimilar materials, particularly strong bonding strength. Laser welding is a high energy of the laser beam as heat source a high precision welding. However, the safe application of new technology is the challenge we face. Laser can damage the eyes, skin, respiratory, central nervous and the whole body. It is generally skin safety standards. View of the laser welding process currently used, the possibility of respiratory hazards in the growth of workers with chronic exposure to hazards by the possibility of laser is growing, so the above five aspects of laser hazards should pay attention.
Research on Leveling Technology of Tailored Laser Welding
Authors: Chen Dong , Zhao Ming Yang , Zhu Tian Xu , Jiang Mei Ling
Published: February 2011

Mismatch is one of the main defects of tailor welded blanks(TWB), and leveling technology is a new method which can solve this problem. The structures, force analysis and flange morphology of the leveling mechanism are studied in this paper, and a three-dimensional prototype is designed. The results have practical significance for improving welding quality of TWB.
Laser Cooling Mechanisms of Chromium Atomic Beam
Authors: Huang Jing , Zhu Bao Hua , Wu Yuan Yuan , Huang Xi
Published: February 2011

A theoretical investigation of 52Cr atomic beam in optical traps was reported, the Doppler and sub-Doppler laser cooling forces were discussed and some characteristics of these forces were shown based on the semi-classical theory. The simulative results indicate that the atomic beam can be collimated by these laser cooling forces, especially by sub-Doppler laser cooling force.
Study on Friction and Wear Behavior of GCr15/1045 Steel under Nano-Particle Additive Conditions
Authors: Wang Wen Jian , Zhuo Hong , Guo Jun , Liu Qi Yue
Published: February 2011

The aim of this study was to investigate the friction and wear behavior of GCr15/1045 steel under different nano-particle additive conditions using a reciprocating horizontal tribometer. The results indicate that the nano-particle additives could decrease friction coefficient of CGr15/1045 steel and reduce the wear of material compared with the dry condition. Nano-particles play an important role of polishing the micro-gibbosity of contact surfaces during the friction process. The nano-particles of Ca10(PO4)6, TiO2 and TiN can form the self-repairing film on the worn surface of 1045 steel. The analysis indicates that the self-repairing effect of nano-particle of TiN is best and the self-repairing effect of nano-particle of TiO2 is worst.
Formation of Structure during the Nonequilibrium Solidification of Zn-5wt%Al Alloy
Authors: Yang Fu Shuang , Ni Feng
Published: February 2011

Formation of structure of Zn-5wt%Al alloy during the nonequilibrium solidification was investigated. Results show that the primary Al-rich phase(α phase) is precipitated during the nonequilibrium solidification. With increasing of the cooling rate, the primary Al-rich phase(α phase) not only becomes less and less but also transforms from cellular crystal to dendritic crystal gradually. Based on this, the eutectic symbiotic region of Zn-5wt%Al alloy phase diagram was researched, and the qualitative phase diagram of eutectic symbiotic region was lined out. In addition, results show that the hypoeutectic structure which is crystallized during the nonequilibrium solidification hasn’t evident core under high cooling rate, and the lamella of hypoeutectic structure is disordered.
Heat Treatment and Morphology Study of Mg-Zn-Y Quasicrystal Alloys
Authors: Wang Zhi Feng , Zhao Wei Min , Li Hai Peng , Wang Yue Mei
Published: February 2011

Mg72.5Zn26Y1.5quasicrystal alloys were treated under different heat treatment process. The microstructures of the alloys were investigated. The quasicrystal and eutectic morphologies and their transformation during heat treatment process were detailedly studied. The results showed that lamellar and dendritic eutectic phases throughout the matrix were evidently formed under heat treatment process 310°C×30min water quenched and 310°C×30min liquid nitrogen deep cooling, respectively. Furthermore, quasicrystals of dragonfly-like and bulk polygon morphology were formed under heat treatment process 575°C×15min water quenched and 700°C×2min cooled with furnace, respectively. Various morphologies’ transformation mechanism during heat treatment process were also studied.
Performance Comparison and Mechanism Analysis of Several No-Bake Sand
Authors: Xia Lu , Huang Jin , Zhang You Shou
Published: February 2011

Performance and mechanism of furan resin no-bake sand, ester-sodium silicate sand, CO2-sodium silicate sand and phosphate no-bake sand were compared by test and analyzed by SEM. Results indicate that furan resin sand and ester-sodium silicate sand have higher dry strength and better humidity resistance, because their fracture modes are cohesive fracture and plastic fracture, there is less crack on their bond membrane. Fracture modes of phosphate sand and CO2-sodium silicate sand are cohesive fracture mainly with a few adhesive fracture and brittle fracture, there is more crack on their bond membrane, which is benefit for moisture to invade, so their compressive strength after hardening and moisture absorption are lower, but phosphate sand has higher dry strength and better humidity resistance than CO2-sodium silicate sand, lower cost and less pollution than furan resin sand, the lowest gas evolution and the best collapsibility , it has a wide application prospect.
The Bending Behavior of Surface Composite Layer Ni/WC Fabricated through Vacuum Infiltration Casting
Authors: Yang Gui Rong , Song Wen Ming , Ma Ying , Hao Yuan
Published: February 2011

Ni/WC surface infiltrated composite layer was fabricated on gray iron substrate through vacuum infiltration casting technique using Ni-based powder and WC particles with different content as raw materials. The compact infiltrated composite layer was obtained on the condition of appropriate choice of processing condition such as pouring temperature, preheating temperature, thickness of preform and the grain size of powder. The infiltrated layer includes surface composite layer and transition layer, and the thickness of transition layer decreases with the increasing content of WC. Three-point bending tests were performed to investigate the mechanical and metallurgical properties of the surface infiltrated composite layer. It was found that load-holding circumstance appeared for specimen with infiltrated layer during the process of three-point bending, and there was no this circumstance for substrate during bending process. The load and displacement decreased with the increasing content of WC when the load-holding circumstance happened. The fracture extended to the substrate for all specimens with surface infiltrated composite layer, and the fracture form was similar for all specimens with different WC content. The WC particles were the source of micro-crack for surface infiltrated layer, and the graphite was the source of micro-crack for gray iron substrate.
Segregation of C, P and Mn in Rapid Solidified Carbon Steels
Authors: Li Na , Zhang Jun Wei , Zhai Lu Lu
Published: February 2011

The quality and properties of steels may be affected due to the segregation of the alloying elements, even though the properties of steels can be improved by adding appropriate amount of alloying elements. Rapid solidification was regarded to be an effective method to reduce or eliminate the segregation of alloying elements. While the segregation of C, P and Mn was also observed in rapid solidified (in silicone oil) droplet carbon steels in this paper. The microstructures of rapid solidified droplets were rather fine. When the P content was less than about 0.09% (in mass) in low carbon steels, P did not show obvious segregation in rapid solidified droplet samples; when the P content raised up to about 0.5% in the samples, both P and Mn showed center segregation even though the content of Mn kept unchanged. So the alloying elements can segregate and even effect the distribution of other elements in rapid solidified steel samples. When the C content increased, the segregation of C was observed in high-C samples, while the segregation tendency is opposite to that of P in high-P samples. For all the droplet samples, the micro-hardness of high-P samples was also much higher than those samples with less P content.
Effects of Melt Treatment on Dendrite Coherency of A357 Alloy
Authors: Chen Zhong Wei , Chen Pei , Fan Li
Published: February 2011

The Dendrite Coherency Point (DCP) of A357 alloy was determined after different melt treatments by double thermocouples, and the coherency solid fraction (fscoh) was calculated by thermal analysis. The results of dendrite coherency properties show that fscoh values increase with increased cooling rate for A357 alloy. For A357 alloys, fscoh values increase after grain refined and melt superheat treatment. The coherency point was found to be dependent on not only the morphology of the dendrites but also the dendrite growth rate.
Ti50Ni25Cu25 Amorphous Alloy Ribbons Progress
Authors: Yang Zhi Huai
Published: February 2011

Properly annealed Ti50Ni25Cu25amorphous ribbons have excellent shape memory founction, superelastic and internal friction. In this article, recent progress in research on the amorphous alloy ribbons of Ti50Ni25Cu25preparation method, phase composition, microstructure of the research status were reviewed. The review mainly includes the phase composition, microstructure evolution, supporting the process of structure change and phase change after heat treatment on Ti50Ni25Cu25crystallized amorphous ribbons.Shortcomings and future researching fields were also pointed out.
Effect of Cooling Condition on Zr-Rich Core Formation and Grain Size in Mg Alloy
Authors: Liu Hong Hui , Ning Zhing Liang , Cao Fu Yang , Meng Zhi Jun , Sun Jian Fei
Published: February 2011

The effects of cooling condition on the Zr-rich core formation and grain size in Mg-Zr alloys were investigated in this study. Four moulds with various cooling rates and different Zr additions were used. The results show that when Zr addition was 1.2%, the Zr-rich cores were round and their diameters increased with decreased cooling rates. When Zr addition content was decreased to 0.7%, Zr-rich cores formed only in the sand mould with the lowest cooling rate used in this study, and the morphology changed to rosette-like. The influence of cooling rate on grain size of Mg-Zr alloys was also investigated.
Research of Synthesizing Biodiesel from Suaeda Salsa by Ultrasonic-Assisted Transesterification
Authors: Yang Qing Li , Zhu Feng , Sun Jie , Qin Song
Published: February 2011

Suaeda salsa oil was taken as raw materials to produce biodiesel by ultrasonic-Assisted transesterification. Single factor experiment and the orthogonal experiment combination design were adopted to study the effects of ultrasonic frequency, ultrasonic power，reaction temperature ，reaction time，catalyst dosage and mole ratio of methanol to oil on biodiesel production rate. The order of factors that influence the biodiesel production rate within the experimental range was as follows: catalyst dosage＞reaction time＞reaction temperature＞mole ratio of methanol to oil. The optimal technological parameters should be as follows: ultrasonic frequency 28kHz, ultrasonic power 210W, reaction temperature 65 , reaction time 10min,catalyst dosage 0.3%and mole ratio of methanol to oil 6, and biodiesel production rate is 97.93% under such conditions.
Study on Morphologies and Structures of Ceramic Coating Prepared by Micro-Arc Oxidation on TC4 Alloy
Authors: Qian Chao Shi , Li Peng Fei , Liu Liang , Guo Feng , Ya Ya
Published: February 2011

In this work, the effects of concentration and mixture ratio of Ca(CH3COO)2•H2O and Na5P3O10 in electrolyte on surface morphology, surface content and atomic ratio of calcium and phosphorus elements, and phase structure of ceramic coating prepared by micro-arc oxidation（MAO）on TC4 titanium alloy were studied, a suitable formula of electrolyte for bio-modification of titanium by MAO was obtained, Ca(CH3COO)2•H2O 20 g/L and Na5P3O10 9.3 g/L. Using this electrolyte with appropriate process conditions, the ceramic coating was prepared with porosity structure and combines well with the substrate. The pores distributed equably on the surface of ceramic coating and the size of the pores was in micron order. The surface of the ceramic coating contains calcium, phosphorus elements and their atom ratio is about 1.69 which nears to that of hydroxyapatite. The ceramic coating was composed of titanium dioxide in different crystal types which have been characterized by the X-ray diffraction (XRD). The anatase titanium dioxide was a major component.
Effect of Aluminium Powder on the Hot Mechanical Properties of Corundum-Silicon Nitride Composites
Authors: Wei Jun Cong , Tu Jun Bo
Published: February 2011

Based on the Al-O-N phase stable diagram and adopting inverse reaction sintering process, corundum-silicon nitride composite refractories were prepared using corundum, silicon nitride, clay and aluminium powder as the main starting materials. The specimens were sintered at 1600 for 3 hours under air atmosphere with different oxygen partial pressure obtained by addition of different amount of aluminium powder. The effects of aluminium powder additions(0, 4wt.%, 8 wt.% and 12 wt.% respectively) on the hot modulus of rupture were investigated .The phase composition and microstructure were tested by means of XRD, SEM and EDAS.The results showed that aluminium would be oxidized, nitrided and displaced as aluminium powder increased during sintering, which reduced the oxygen partial pressure in the specimen. The hot modulus of rupture (HMOR) increased considerably due to large amounts of fibrous sialon formed.
Microstructural Refinement Process of Pure Magnesium by Pulse Magnetic Field Treatment
Authors: Wang Bin , Sun Ming Li , Chen Jing De , Wei Yong Bin
Published: February 2011

The effects of pulsed magnetic field on the solidified structure of pure Mg were investigated. Fine uniform equiaxed grains are acquired in the whole ingot from the PMF treatment, in contrast with the coarse columnar grains observed in conventional casting, and the average grain size is refined to 260 m with a 5Hz PMF treatment. The mould size also affects the grain refinement and the most suitable inner diameter of the cylindrical mould is set at 50mm. Pulsed magnetic field increases melt convection during solidification, and the violent agitation causes warmer liquid to fracture the tip of columnar dendrites or to break off dendrite branches and promote the formation of an equiaxed structure, with the broken pieces transported into the bulk liquid acting as nuclei.
Research on Microstructure and Mechanical Properties of High Boron Cast Steel
Authors: Xu Liu Jie , Zhang Guo Shang , Li Ji Wen , Dong Zhan Wu , Wei Shi Zhong
Published: February 2011

In recent years, high chromium cast irons have been widely applied in many fields because they have high hardness and abrasion resistance. However, high chromium cast irons are also expensive because much alloying elements, such as chromium, molybdenum and nickel, are added into them. In order to resolve above question, a new abrasion-resistant steel with high boron content was developed in this paper. The new high boron steel, with 0.6%~0.8%B and 0.65% C, was prepared using sand casting method. The microstructure and mechanical properties were researched. The results show that the solidification microstructure of as-cast high boron steel consists of boride (FeB) and matrix composed of pearlite, ferrite, and bainite. And the borides distributes along grain boundary in the form of network. After quenching at 980°C and tempering at 250°C, the FeB transforms to Fe2B, and the matrix transforms lath martensite. The hardness of as-cast high boron steel is 43HRC, and its impact toughness is 5J/cm2. After heat treatment, they increase to 56 HRC and 7J/cm2, respectively, approximating that of high chromium cast irons. The new high boron cast steel have a potential in stead of high chromium cast irons