bluuebunny/crossref_metadata_2025 huggingface dataset:
Tensile Properties and Strain Hardening Behavior of a Friction Stir Welded AA2219 Al Alloy
Authors: Xu Wei Feng , Liu Jin He , Chen Dao Lun , Luan Guo Hong , Yao Jun Shan
Published: July 2011

Microstructures, tensile properties and work hardening behavior of friction stir welded (FSWed) AA2219-T62 aluminum alloy (in its one-third bottom slice of a 20 mm thick plate) were evaluated at different strain rates. While the yield strength was lower in the FSWed joint than in the base metal, the ultimate tensile strength of the FSWed joint approached that of the base metal. In particular the FSW resulted in a significant improvement in the ductility of the alloy due to the prevention of premature failure caused by intergranular cracking along the second-phase boundary related to the presence of the network-like grain boundary phase in the base metal. While stage III and IV hardening occurred after yielding in both base metal and FSWed samples, the FSW led to stronger hardening capacity and higher strain hardening exponent and rate due to the enhanced dislocation storage capacity associated with the microstructural change after FSW. The fracture surface of the FSWed joint was mainly characterized by dimples and tearing ridges along with micropores.
The Interlayer Designation for ZTM Ceramics and Fibre Joining
Authors: Zhao Ying Na , Liu Jia Chen , Wang Cai Fen , Zhang Wen Li
Published: July 2011

The joining materials of density ceramics and the fibre would be potential application value as seal materials at high temperature condition or in aerospace field. According to chemical composition consistent principle of ceramics/interfaces/fibre, the interlayer of mullite ingredient was designed which based on the ZTM ceramics composition. Using the absorber-microwaves properties of Al-Si alloy, the joining of ZTM ceramics and fibre materials with interlayer was achieved by microwave hybrid heating method. The experiment results indicated that the volume expansion of interlayer was about 4.8% when the content of Al-Si was 24 wt % in the compositions. The interlayer ingredients were mullite, zirconia and alumina after sintering. The fibres were better joint with interlayer by microwave sintering than by traditional method.
Research on the Mechanical Properties and Residual Stress of HVOF Sprayed Nanostructured WC-17Co Coatings
Authors: Gou Guo Qing , Huang Nan , Chen Hui , Li Da , Liu Yan , Ji Hua
Published: July 2011

Nanostructured WC-17Co coatings, nanostructured WC-12Co coatings, conventional WC-17Co coatings were prepared by means of High Velocity Oxygen Flame (HVOF) technique. The characteristic of powders and coatings of nanostructured WC-17Co coatings, hardness of different coatings, distribution gradient of the hardness of the nanostructured WC-17Co coatings in the depth direction, fracture toughness and interface fracture toughness of different coatings, residual stress of different coatings, different phase and distribution of WC phase in the depth direction were investigated. The results indicated that the micro-crack is spread along the phase interface where the brittle phase are more in the Co rich area , where there are more different properties in the Co rich area and W rich area, where there are more defects close to the intend end in the W rich area, even spread through the WC particles in microcosmic and the different residual stress of different phase are because of different melting point and different expansion coefficient , so the WC, W2C produced compressed stress, the Co6W6C produced tensile stress. The residual stress manifested from higher to lower in the depth direction of the coatings.
Effect of Magnetic Field Frequency on Microstructure and Properties of AZ31 Magnesium Alloy Welded Joint with GTAW
Authors: Su Yun Hai , Liu Zheng Jun , Liu Duo
Published: July 2011

In this investigation, in order to research the influence of magnetic field frequency on microstructure and properties of magnesium alloy welded joint, the AZ31 magnesium alloy plates which was 5mm were welded by GTAW under longitudinal magnetic field. The tensile test, hardness test and SEM were taken place to analyze the properties and microstructure of welded joint under different magentic field frequency. The acting mechanism of magentic field on welded joint was studied. The results show that: External magnetic field can improve the properties of magnesium alloy welded joint. The optimal mechanical property will be obtained when Im=2, f=20Hz, which the ultimate tensile strength is 231Mpa and the micro-hardness is 76.2HV.The magnetic field can produce electromagnetic stirring, which can refine crystal grain through breaking the pine-tree crystals with proper magnetic field current and frequency. The properties of welded joint will been improved by these fine crystal grain.
Completely Inelastic Collision to Confirm Maximum Punch Pressure Force of Cold Pressure Welding
Authors: Zhao Sheng Dun , Xu Fan , Zhao Ren Feng , Zhong Bin
Published: July 2011

The maximum punch pressure force (TMPPF) of cold welding pressure affects not only the performance of the welding bonding but also the amount of the area of welding bonding. If punch force is more bigger, it may be take place cracks, stress concentration and welding concave pits, which affect application of materials and increase incidence of faults. The process that punch pressure of cold welding pressure applied on sheet materials to attain welding bonding is simplified beam in cold pressure welding. Under normal circumstances it is an important method to TMPPF by the manner of experiment, but the method to attain TMPPF is limited. In the paper completely inelastic collision theory is applied to explain the process of cold welding pressure, the theory of completely inelastic collision offers principle theory to attain TMPPF. In this paper, two supposes are put forward, on the basis of two supposes the critical velocity is attained. At the same time, critical kinetic momentum or critical kinetic energy will be attained. On the basis of the law of conservation of energy, energy balance equation is attained, which will drop in calculating difficulty of the non-linear process of cold pressure welding and decrease calculated amount. In this paper on the basis of the process of collision all phases are analyzed. Indeed elastic-plastic deformation phase is completely inelastic collision phase, and from point of view of collision to calculate energy loss. At the same time, to suppose other plate is utter stiff can attain critical velocity, thus, to achieve the equation of TMPPF.
Residual Stress Characterization of A7N01-T5 Welds for High Speed Train by X-Ray Diffraction and Verification
Authors: Ji Hua , Gou Guo Qing , Chen Hui , Li Da , Ma Chuan Ping , Tian Ai Qin , Guo Zhi Cheng
Published: July 2011

Welding residual stresses have an effect on many aspects of the integrity of structures but are normally one of the largest unknown stresses. Residual stresses are difficult to measure and to estimate theoretically but are often significant when compared with the service stresses. In this paper, measurement of residual stresses by X-ray diffraction technique using two different fitting methods (Gaussian and PearsonⅦ) was compared with analysis of a sample geometry by theoretical finite-element methods. The square map RS characterization of A7N01-T5 welds was shown. The results indicate RS measured by XRD and simulated by finite-element method show good qualitative agreement.
The Effect of Nano-Cu Particles on Mechanical Properties of Micro-Joining Joint with Lead-Free Solder
Authors: Shen Ying Ming , Qi Fang Juan , Xie Min , Li Jian
Published: July 2011

The effect of nano-Cu particles on mechanical bend reliability of micro-joining joint with Sn-3.5Ag lead free solder was studied in this paper. The results show that 0.5% nano-Cu composite lead free solder show significantly better shearing strength and mechanical bend fatigue properties than eutectic Sn-3.5Ag solder paste, 1.0% nano-Cu composites and 1.5% nano-Cu composites. The further analysis shows that adding nano-Cu particles make much effect on intermetallic (IMC) in the interface of micro-joint and the inside of the solder joint. The different interface of micro-joining joint induced different mechanical properties.
Liquid Phase Separation of Cu-Fe Weld Metal of Manual SHS Welding
Authors: Xin Wen Tong , Li Zhi Zun , Li Bao Feng , Wu Yong Sheng
Published: July 2011

In order to solve a problem of the low mechanical properties of Manual SHS Welding joint, a new iron-base manual SHS welding material was developed by CuO+Al and Fe2O3+Al being the thermit and adding iron alloy materials. The structure and properties of the welded joint were studied. The results indicated that: Cu-Fe alloy in the molten pool experiences liquid phase separation during rapid solidification, and the weld metal is macroscopically separated into one Fe-rich part and one Cu-rich part. Fe-rich phase is filled in the welding line. The higher Fe supersaturation is in the Cu-Fe weld metal, the more notablely and quickly liquid phase separates. At the same time, tensile strength of the welded joint was close to 520 MPa, and impact toughness was close to 32.1J/cm2, and surface hardness was also close to HB360. It also indicated this technology can meet the need of repair of metal parts in field.
Study on Performance of Inertia Radial Friction Welding of Copper-Alloy to 35CrMnSi Steel
Authors: Wu Wei , Zhu Ling Yun , Wu Guang Feng , Xu Hui Bin
Published: July 2011

The joint property of aldary (T3 copper, B5 cupronickel and H96 brassiness) with 35CrMnSi by the use of inertial radial friction welding techniques is studied to meet the requirements of product operation . The microstructure of the welding joint, shear testing, vickers hardness and electron probe tests are carried out to verify the material weldability. The results show good performance of T3 copper, B5 cupronickel and H96 brassiness welded well with steel. The joints shear strength is more than 200Mpa, and no air hole flaw in weld seam that often occur in general fusion welding with dissimilar material. The welding properties can satisfy the requirements of the products. The results also indicate that under the same welding specification, the region of HAZ is related to thermal conductivity and melting point of copper-alloy, the microstructures of HAZ on B5＋35CrMnSi steel side is wider than others .
AOP's Modeling Research and Model Transformation with ATL in MDA
Authors: Zhang Jing Jun , Wei Fei , Li Hui
Published: July 2011

With Aspect Oriented Programming(AOP) technology, Model Driven Architecture(MDA) and ATLAS Transformation Language(ATL), this paper proposes a PIM framework of based on OOP and a PIM framework of based on AOP, also proposes a idea with ATL accept model conversion signals to model transformation.
Crack Failure Analysis of Q235B Welding with 304 Austenitic Stainless Steel of Tube and Shell Condenser
Authors: Zhang Xian Liang , Chen Rong Fa , Dai Liang Gang , Liu Tao , Pan Yi
Published: July 2011

Tube and shell condenser is an important component of soybean softening equipment, and its structure is Q235B welding with 304 austenitic stainless steel pipes. During the using process of this product, it appears crack failure .In order to find the reason of crack failure, the welded joint was analyzed by SED, XRD, EDXRF and metallographic microscope in detail, and some improvement measures and solutions are put forward to avoid crack failure in this paper.
Effect of Yttrium and Magnesium Segregation on Microstructure and Mechanical Properties of Heavy Section Ductile Iron Castings
Authors: Chen Wei Ping , Liu Zhe , Deng Yu , Luo Jie , Chen Yong Cheng
Published: July 2011

Ductile iron specimen with dimensions of Φ590mm×800mm were prepared by treating the melt with an yttrium-containing nodulizer. Cooling curves at four locations____the center location, the location 85mm distant from the center, the location 170mm distant from the center and the location 255mm distant from the center of the heavy ductile iron casting Φ590mm×800mm was obtained. The effect of yttrium and magnesium on microstructure and mechanical properties was investigated, and the factors on the distribution of chunky graphite in the specimen were discussed as well. The results show that the largest amount of chunky graphite and the lowest mechanical properties appear at the location 170mm distant from the center. Excessive yttrium and magnesium content at the location 170mm distant from the center is the main factor for the large amount of chunky graphite. The characteristics of the solidification mode____pasty solidification and the considerably long solidification of the casting are the basic reasons for the distribution of chunky graphite of the heavy ductile iron casting Φ590mm×800mm.
Numerical Simulation of Flowage and Bath Surface Behavior in Continuous Casting Mold with Electromagnetic Brake
Authors: Xu Chang Jun , Hu Lin , Zhang Song , Hou Ai Hua , Wang Qi
Published: July 2011

Jet shape of submerged nozzle (SEN), flowage, fluid level fluctuation and the superheat on bath surface in mold under the static electromagnetic field were 3-D simulated by using the CFX, commercial software. The results showed that electromagnetic brake (EMBR) can alter jet shape of SEN and fluid flow in the mold. And on the premise of controlling fluid level fluctuation of mold bath effectively, higher superheat of bath surface is obtained.
Effects of Rare Earth Dopants on Crystal Structures of Bismuth Molybdate Catalysts
Authors: Cheng Ying Zhi , Xue Li , Sun Xiu Yu , Hu Zhong Bo
Published: July 2011

Crystal structures of Bi2Mo3O12 and Bi1.8Ln0.2Mo3O12 (Ln = Ce, Nd, Dy, Er) were studied using Rietveld structural refinements of X-ray powder diffraction data. Substitution of 10 mol% Ln for Bi produced changes in lattice parameters, bond lengths and distances between metal ions. These changes such as decreases in average bond lengths of Mo1O4 tetrahedra and variations in the distances between adjacent metal ions on the same plane could be ascribed to different ionic radii and electronegativty of Bi and rare earth atoms, and might be related to catalytic activity of bismuth molybdate for the selective oxidation and ammoxidation of alkenes.
Study on the Relationship between Tensile Sample Lamination and Inner Quality of Q345 Slabs
Authors: Cao Tong You , Yang Zhi Zheng , Yuan Fan Cheng , Shuai Guo Yong , Yang Xin Quan
Published: July 2011

In order to find the relationship between tensile sample laminations and inner quality of Q345 slabs, casting trials in conditions of with and without EMS and different superheating have been carried out. It is found that slab inner quality can be improved a lot with EMS, center equiaxial grain ratio increases greatly. Lowering superheating leads to downgrading of center deviation, however, center equiaxial grain ratio increases not too much compared with EMS. Tensile samples produced by above-mentioned measures do not break in the center area.
Deflection Test on CFST Arch Bridge with CFRP Slings
Authors: Cao Guo Hui , Xie Zhen Yu , Wen Ming Cai , He Ran
Published: July 2011

The ultimate bearing capacity test is carried on CFST arch bridge model with CFRP slings, and the deflection of tie-beams, CFST arch, crossbeams, decks is also tested. Studies have shown that before the sliping of 4# CFRP sling, the deflection growth of east and west tie-beam, east and west arch both has good symmetry. The deflection growth of crossbeams and decks also has good symmetry, but after the sliping of 4# CFRP sling(located at the middle of west tie-beam), the structural internal forces redistribution appeared. The deflection of west tie-beam increased suddenly, and the mid-span deflection of west tie-beam is larger than that of east tie-beam by 14.6%. The mid-span deflection of east arch is larger than that of west arch by 9.9%. The deflection of crossbeam at 3L/8 and L/4 sections are respectively larger than those of crossbeam at 5L/8 and 3L/4 sections by 13.8% and 5.3%, The deflection of 3#, 2# and 1# decks are respectively larger than those of 4#, 5# and 6# decks by 7.8%, 13.2% and 17.1%. After the snapping of 10# CFRP sling(located at 3L/8 section of east tie-beam), the structural internal forces would appear redistribution. The deflection of east tie-beam would increase suddenly. The mid-span deflection of east tie-beam is larger than that of west tie-beam by 31.7%, and the mid-span deflection of east arch is larger than that of west arch by 21.3%. The deflection of crossbeam at 3L/8 and L/4 sections are respectively larger than those of 5L/8 and 3L/4 sections by 24.7% and 22.5%. The deflection of 3#, 2# and 1# decks are respectively larger than those of 4#, 5# and 6# decks by 16.2%, 24.5% and 28.6%.
Model Study about the Influence of Superheat on Macrosegregation Formation in Continuously Cast Bloom of Special Steel
Authors: Hou Zi Bing , Cheng Guo Guang
Published: July 2011

Aiming at the facing problems of the actual continuous caster in a certain steel mill, a solidification-process heat transfer model about continuously cast bloom of special steel was first established, then the influence of superheat on macrosegregation formation was studied. It is shown that the crater length will become longer, the shell thickness will become thinner with increasing the superheat. Meanwhile, when decreasing the superheat , the value of will decrease and the value of H will obviously increase, then the equiaxed crystal ratio will be raised greatly. However, the bloom centre solidification time will increase. Consequently, attention should be paid to this point when decreasing the superheat in order to lessen the extent of macrosegregation.
Effects of Milling Time and Annealing Schedule on Mechanical Activation Synthesis of Brownmillerite Structural Ca2Fe2O5
Authors: Wang Fen , Zhao Chun , Zhu Jian Feng
Published: July 2011

The brownmillerite structural Ca2Fe2O5is successfully prepared by high energy milling starting from CaCO3and Fe2O3. The composition and transformation of phase and structure with different milling time and annealed at 800 °C for 24 h were characterized by the X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) analysis. The results indicate that the high pure brownmillerite structural Ca2Fe2O5could be efficiently synthesized at lower temperature by the mechanically activated mixtures.
Effect of Hole Distance and Hole Number on Bubble Behavior during Gas Injection with Multi-Hole Orifices
Authors: Jiang Fang , Cheng Guo Guang
Published: July 2011

Physical model experiments have been performed to clarify the effect of hole distance and hole number of multi-hole orifices on bubble behavior during metal refining process. It is found kA/V firstly decreases and then increases with the hole distance increasing. However, kA/V shows little further increase when hole distance exceeds a critical value. There exists an optimal hole distance for the multi-hole orifice, which is dependent on the gas flow rate, the hole diameter and the hole number in the multi-hole orifice. kA/V firstly increases with the hole number increasing, and then remains unchanged when hole number exceeds a critical value. There also exists an optimal hole number for the multi-hole orifice, which is closely related to the gas flow rate.
A Novel CuO-TiO2 Composite Photocatalyst and its Degradation of Methyl Orange under UV Irradiation
Authors: Wu Shi De , Zhu You Qi , Li Chao , Wei Ying Liang
Published: July 2011

A novel CuO-TiO2 composite photocatalyst was prepared by a redox process coupling with sol-gel method. The morphology and structure of the as-prepared samples were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Photocatalytic activity of the CuO-TiO2 composite photocatalyst was evaluated in terms of the degradation of Methyl orange (MO) in aqueous solution under UV light irradiation. The results show that the as-prepared composite consisted of monoclinic-phase CuO-nanotubes and TiO2 nanoparticles, in which TiO2 nanoparticles were dramatically decorated on the CuO-nanotubes, exhibits a high catalytic activity to decolorize MO. According to the experimental results, 1.27wt % was the optimal loading for CuO-doped TiO2 photocatalyst.
A New Photochromic Diarylethene for Optical Storage
Authors: Yan Pei Jian , Pu Shou Zhi , Cui Shi Qiang
Published: July 2011

A new photochromic diarylethene, 1-(2-ethylbenzo[b]thiophen-3-yl)-2-(2-cyanophenyl) perfluorocyclopentene (1o), was synthesized, and its photochromic and fluorescent properties were investigated. This compound exhibited reversible photochromism and fluorescence photoswitches both in solution and in PMMA films. Using diarylethene 1c/PMMA film as recording medium, optical recording was performed successfully.
Numerical Simulation of Interaction between Coal Derrick and Foundation in Freeze - Thaw Process
Authors: Li Dong Wei , Fan Ju Hong , Wang Ren He
Published: July 2011

With the increase of the depth of frozen sinking, mine permanent derrick was located into the the frozen wall scope. The internal force distribution law of the shaft – tower foundation was obtained by the field measurement of shaft – tower foundation pressures, reinforced internal force, concrete strain, foundation deformation, and other mechanical quantities. The numerical Simulation of interaction between coal derrick and foundation in freeze - thaw process showed that: Field measurement and numerical simulation of the same laws and values were in good agreement. It has very important theoretical and practical significance for the safe production of derrick and future derrick foundation design in freezing method construction.
Morphology and Electrical Properties of Nano-Sized LiFePO4 Cathode Materials
Authors: Yan Hao , Xu Yun Hua , Wang Juan , Shao Chong Yang
Published: July 2011

Nano- and micro-scaled LiFePO4 was synthesized by hydrothermal synthesis method using disodium ethylenediamine tetraacetate (Na2EDTA)-assisted to avoid the Fe(II) ions from oxidation and control the growth of the crystal. The as-synthesized samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), The SEM showed that the pH value of the synthesis solution played a key role in the formation of the ﬁnal products with different morphologies. Charge–discharge cycling performances were used to characterize its electrochemical properties. The results indicated that the nano-sized LiFePO4 presents enhanced discharge capacities (148 mAhg−1 at 0.1C-rate) and stable cycling performance. This study offered a simple method to design and synthesis nano-sized cathode materials for lithium-ion batteries.
Influence of La and Ce on Microstructure and Properties of Cu-Cr-Zr Alloy
Authors: Dai Jiao Yan , Mu Si Guo , Wang Yong Ru , Yang Xiao Pan , Li Jie
Published: July 2011

The degassing and dedusting mechanism of La and Ce during non-vacuum melting process of Cu-Cr-Zr alloy were analyzed by thermodynamics. The gibbs free energy changes of reactions of La and Ce with some impurties such as O2, H2, S, P and Si, were calculated to discriminate the possibility of reaction during the melting process, respectively. In addition, the effect of La and Ce on microstructure and properties were studied. The results show that La and Ce can react with O2, H2, S, P and Si, which improves the effect of degassing and dedusting remarkably; the addition of La and Ce can eliminate pine-tree crystal, fine grain and clear grain bourdary.
Researches on the Properties of Stearate-Carboxymethyl Konjac Glucomannan Ester Prepared by Microwave Method
Authors: Zeng Xiao Man , Liu Bei Yu , Wang Jian , Zhong Geng , Xia Yu Hong
Published: July 2011

In this study, microwave heating was used for the preparation of stearate-carboxymethyl konjac glucomannan ester (SCMK), which introduced hydrophilic carboxymethyl and hydrophobic stearate groups on konjac glucomannan (KMG) backbone. The physico-chemical properties and structure of SCMK were investigated. Results show that the viscosity of SCMK is much lower than that of KGM, but larger slightly than the carboxymethyl konjac glucomannan (CMK) and the viscosity is still stable after being placed for 48 h at ambient temperature. Its transmittance decreases and the resistance ability of SCMK solution to salt/sugar as well as base have been significantly promoted. Moreover, SCMK with substitution degree (DS) of 0.02 is proved to be a sound oil/water emulsifier which its HLB value is 13.01. In FTIR spectrum, the absorption peak of SCMK decreases at 2161.84 cm-1 and 2360.74 cm-1. Meanwhile, TGA indicates that SCMK is less thermal stable than KGM and CMK, but is still good.
High Overload Penetration Test and Analysis of the Multi-Layer Steel Target
Authors: Liu Li Shuang
Published: July 2011

High-g accelerometer and storage test system is designed for the measurement of multi-layer steel targets penetration. The penetration test of the double layer steel target is performed, and the verload acceleration is obtained when the projectile penetrates the steel target. According to the overload data, the effective overload accelerations are concluded. The effective overload accelerations gained when projectile penetrates the double steel targes are 81078g and 152061g respectively. Also from the calculation, it can be concluded that the test errors are all less than 10%, which can meet the requirement of penetrating multi-layer steel targets.
Influence of Temperature and Relative Humidity on Perm-Selectivity of PET Packaging Film
Authors: Guo Yan Feng , Ma Xian Ping , Yan Yu , Fu Yun Gang
Published: July 2011

The main feature of this article is the investigation on the influence of temperature, relative humidity, film thickness on permeability of PET packaging film, the analysis of perm-selectivity of the packaging films for oxygen gas and carbon dioxide gas, and the evaluation on experimental formulas of water vapor, O2 and CO2 gas permeating rates on the basis of gas molecular osmotic reaction kinetics and regression analysis. The comparison between experimental studies and calculation indicates that: (1) with increment of ambient temperature water vapor, O2 and CO2 permeating rate of PET films and PET/Al film also rise, and the logarithm of water vapor, O2 and CO2 gas permeating rates has linear relation with the reciprocal of thermodynamic temperature, and (2) the influence of relative humidity on water vapor permeating rate of PET film with thickness 12µm is the least, and that of PET film with thickness 20µm and PET/Al film with thickness 18µm is a little obvious. (3) The PET films hold remarkable perm-selectivity for O2 and CO2 gas, and CO2 gas permeating rate is about two times of O2 gas, yet O2 and CO2 gas permeating rates of PET/Al film are both very low and have small difference, so the PET/Al film has better barrier performance than the PET film.
Development and Evaluation of a High-Strength and Anti-High Temperature Pre-Crosslinking Gel
Authors: Lv Kai He , Shi Tao , Zhu Dao Zhi , Liu Yang , Qiao Wei Gang
Published: July 2011

There are many kinds of pre-crosslinking gel being used at present, but their high temperature resisting performance are poor. The general temperature resisting capacity is only about 120°C. Aiming at the poor resistance to high temperature of current pre-crosslinking gel , an anti-high temperature pre-crosslinking polymer gel is developed in this paper. Experimental results show that this product has appropriate swelling ability, better anti-extruding strength, better deformability and elasticity. The temperature resisting capacity in freshwater can reach as high as 150°C,and it still has comparatively higher strength after high temperature treatment.
Control of Cold Welding Cracks in 30CrMnSi Steel by Welding with Trailing Impacting and Rolling
Authors: Yang Jian Guo , Huang Lu Yong , Pan Hai Bo , Liu Xue Song , Fang Hong Yuan
Published: July 2011

As a kind of the high strength low alloy steel (HSLA), 30CrMoSi has been used widely in some industrial fields. However, just like some HSLA, this steel also faces some problems when it is welded, especially such problem as cold cracking in the welded joints. In this paper, the cold welding cracks and microstructure of the joints of 30CrMoSi steel were studied by scanning electron microscopy (SEM) and optical microscopy (OM), and a method called welding with trailing impacting and rolling (WTIR) was utilized to solve the problem mentioned above by decreasing the residual welding stress which is one main factor to lead to cold welding crack in the joint of HSLA. The crack-free joints of 30CrMoSi steel were obtained by using proper parameters.
Investigation of Very High Cycle Fatigue Behavior of TC17 Alloy
Authors: Cheng Li , Gao Chao , Shen Jing Sheng , Li Ning , Chen Wei , Li Quan Tong
Published: July 2011

According to the loading characteristics of engine blades, a vibration bending fatigue system by using the ultrasonic fatigue test technique has been developed and the specimen is designed by finite element method, fatigue tests of TC17 between 106and 109cycles have been completed in this paper. The results show that the fatigue life of specimen increases over 107cycles and the initiation of fatigue cracks transfers from only in the surface of specimen to both in the surface and the sub-surface with loading decreasing.
Materials and Fabrication Issues of Micro V-Groove for Optoelectronics Packaging
Authors: Zheng Yu , Duan Jian
Published: July 2011

Micro V-groove is an important optical component in the packaging of optoelectronic devices, which holds the position of the optical fibers. The micro V-groove can be fabricated by three main techniques on different materials: wet etching, ultra precision machining and molding press. The main parameters, which determine the micro V-groove quality, include core pitch, surface roughness and cured adhesive height. In this paper, three fabrication techniques are discussed to address the future needs of the next-generation optical fiber communication technology. The advantages and disadvantages of each fabrication technique are discussed with the quality issues. The findings can be served as guides for the materials and fabrication in micro V-groove in optoelectronic packaging.
Fabrication of Al/SiC Nanocomposite Powders via In Situ Powder Metallurgy Method
Authors: Moazami Goudarzi Mohammad , Akhlaghi Farshad
Published: July 2011

In the present investigation, the in-situ powder metallurgy (IPM) method was utilized to synthesis aluminum alloy matrix composite powders containing SiC nanoparticles. Specified amounts of SiC particles (with a size in the range of 250-600 µm) together with SiC nanoparticles (average size of 60 nm) were preheated and added to aluminum melt. This mixture was stirred via an impeller at a certain temperature for a predetermined time. The kinetic energy of the impeller was transferred to the melt via the non-wetting SiC particles and resulted in melt disintegration. The liquid droplets created by this process were then solidified upon cooling the blend resulting in a mixture of Al powders and SiC particles. This blend was passed through a 250 µm sized sieve and a mixture of Al powders and SiC nanoparticles was produced which could be subsequently used as a feedstock for preparation of Al-SiC nano-composites via the standard powder metallurgy methods. The results confirmed that the surface condition (oxidized vs. as-received), amount and different proportions of the added nano-sized and micron sized SiC particles as well as the chemistry of the metallic charge (CP aluminum or Al-1wt.%Mg) affect the size distribution and yield of the resultant sub-250 µm sized powders. The scanning electron microscopy (SEM) studies revealed that Al/SiC composite powders containing nano-sized SiC particles could be produced by using Al-1 wt.% Mg as the matrix alloy.
An Efficient Synthesis of 5-Arylidene Barbiuric and Thiobarbituric Acids Catalyzed by Mg(NTf2)2 in Water
Authors: Yang Zhi Huai
Published: July 2011

5-Arylidene barbituric and thiobarbituric acids have been synthesized by Knoevenagel condensation of various aromatic aldehydes with barbituric or thiobarbituric acids in the presence of 1 mol% Mg(NTf2)2in water in high to excellent yields within short times.
Experimental Study and Finite Element Analysis of the Seismic Behaviors for Steel Fiber Reinforced High-Strength Concrete Frame Exterior Joints
Authors: Liu Hai Tao , Wang Ting Yan
Published: July 2011

Based on the experimental results of three steel fiber reinforced high-strength concrete frame exterior joint under the low cycle loading, the numerical simulation by nonlinear finite element method was adopted to analyze their behaviors and to explore the influence of axial compressive ratio on seismic capacity of the joint. The results indicate that the increase of the axial compressive ratio enhances the restriction role to the joint core area concrete, slows down the degeneration degree of shearing-resistance capacity and stiffness, enhances the shearing-resistance capacity of the core area, the joint ductility and the energy dissipation capacity. The finite element analysis coincides well with the experimental results. In finite element analysis, steel fiber was equated with micro-reinforcement, and then put evenly into the concrete unit. Compared with the test results, the method of taking the steel fiber and concrete as a holistic model was thus validated.
Effect of Die-Swell Ratio on Polyacrylonitrile As-Spun Fiber Formation
Authors: Ji Bao Hua
Published: July 2011

In this paper, the effect of die-swell ratio on the microstructure and properties of as-spun fibers was systematically analyzed by electron microprobe analysis (EMPA) and the measurement of die-swell ratio, boiling-water shrinkage, porosity and mechanical properties. The formation mechanism of the spin orientation and skin-core structure were revealed. It was shown that with different die-swell ratio, the spinodal decomposition speed and the orientation degree between the outer and inner of as-spun fibers is different, which leads to a difference of denseness and hardness between the outer and inner, thus the skin-core and porous structures are formed. A small die-swell ratio leads to an enhanced spin orientation, a reduced skin-core difference and a more compact and homogeneous microstructure. As a result, the breaking tenacity of as-spun fibers and resultant precursors all increased.
The Sonochemical Fabrication for the CaCO3 Nanocrystals with Different Morphologies
Authors: Jia Zhi Yong
Published: July 2011

We have used the sonochemical approach to synthesize single crystals CaCO3 nanocrystals with various anisotropic shapes of such as, nanowires, nanosheets and unusually obtained nanoplates without using any template at room temperature. The complex interplay between crystallization processes and self-assembly resulting from spatial constrains has been investigated through studying the structural evolution of metastable intermediates synthesized. The impurity inducing crystallization has been proposed for a reasonable understanding of the novel crystallization pathway under the condition of sonication. Moreover, this approach is suitable to the anisotropic single crystals synthesis of other alkaline earth carbonates such as SrCO3 and BaCO3. It also gives a new demonstration of sonochemical effects on the crystallization and assembly of block building in the mesoscale.
Design Optimization of the Aerial Lift Boom through the Finite-Element Analysis (FEA)
Authors: Hong Yong , Yu Seokjun , Lee Jaejung , Ha Hyeonsu , Hong Dong Pyo
Published: July 2011

The multi-stage boom consisting of several booms is used in order to develop the aerial platform truck that can be used in a working radius that is higher and safe. Because the length increases compared with the width or the height of the structure, the intensity and rigidity are lowered along with the safety. Accordingly, a countermeasure is needed. Therefore, in this research, when designing of the high ground work difference Boom System, the safety the stress of the considered boom the analyze method and experimental method tries to be evaluated through the comparison. The finite-element analysis(FEA) compared the Strain value which is obtained through the resolution value and actual experiment by using the Ansys,that is the general purpose program, and proved this safety.
Mechanical and Tribological Properties of Nylon 1212 Modified with Brown Corundum Ash and Solid Lubricants
Authors: Zhang Gao Liang , Zhao Qing Xiang , Liu Min Ying , Fu Peng , Yu Yi Bo , Xu Jian Wen
Published: July 2011

Brown Corundum Ash(BCA) was used to modify nylon 1212(PA1212), which is produced during the production of electric fused brown corundum alumina and will causes serous environmental pollution if it is not recycled. In order to improve the tribological property of PA1212 composites, Graphite, MoS2 and PTFE were used. The composites were prepared by a twin-screw extruder through melt intercalation. The mechanical properties and the wear resistance of the PA1212/Brown Corundum Ash/graphite/MoS2/PTFE composite were studied. The shearing area of composite and the worn surfaces were examined by scanning electric microscope (SEM).
Experimental Study of the Packaging Failure for Optical Fiber Arrays
Authors: Duan Ji An , Zheng Yu
Published: July 2011

Optical fiber array is a key component in the assembly of planar optical waveguide devices and enable greater channel counts than previously. However, assembling optical fiber array has been a challenge due to the stringent performance and reliability requirements posed by optical fiber communication applications. This paper investigates the causes of the failures involving the adhesive including: surface contamination, air entrapment, uneven curing, curing shrinkage; and thermal expansion coefficient mismatch.
Springback Simulation in Stretch Bending of Aluminum Extrusions Using Static Implicit and Dynamic Explicit FE Codes
Authors: Li Xiao Qiang , Li Hui , Li Dong Sheng
Published: July 2011

First stretch bending process of aluminium extrusions given by Norwegian scholars is simulated by using revised model proposed in the paper. That maximum die force calculated is closer to experiment than Norwegian scholars’ one demonstrates that the revised model is rather accurate in forming simulation and lays the foundation for later springback simulation. Then springback is simulated by using dynamic explicit and static implicit FE codes, respectively. The influences on cross-sectional distortion and springback of two codes are compared. It is shown that dynamic explicit FE code can predict cross-sectional distortion accurately and static implicit FE code overestimates it. Neither of two codes can predict springback accurately. Dynamic explicit FE code overestimates it and static implicit one FE code underestimates it.
Thermo-Mechanical Properties and Microstructure of Al2O3-SiC-SiAlON Composites
Authors: Liu Xin Hong , Xu En Xia , Zhou Chao Jie
Published: July 2011

The composite specimens have been prepared using fused corundum, silicon and bauxite-based β-SiAlON powder as starting materials. The physical properties, high temperature modulus of rupture (HMOR), thermal shock resistance (TSR), phase composition and microstructure of the specimens after firing at 1500°C have been studied. The results show: (1) Al2O3-SiC-SiAlON composites are sintered well at 1500°C. (2) HMOR and TSR of the specimens increase with increase of Si content, high temperature properties are further increased with appropriate β-SiAlON addition. (3) The in-situ formed SiC and O’-SiAlON fill in the interstices of corundum skeleton structure, forming interlocking network structure, thus creating strengthening and toughening effects.
Anglicizing Modern High-Rise Building Modeling Design Technique
Authors: Wang Ya
Published: July 2011

This paper analyses the basic physique and the modeling technique. With the understanding of the language characters of the shape element, the complicated space in the high-rise building model will be analyzed thoroughly in order to use them in design and practice.
Study on the Durability of Concrete with Mineral Admixtures to Sulfate Attack by Wet-Dry Cycle Method
Authors: Liu Guan Guo , Ming Jing , Zhang Xiong Wen , Ma Ai Bin
Published: July 2011

Sulfate attack is one of several chemical and physical mechanisms of concrete deterioration. In actual situation, concrete structures always suffer from the coupled effects of multifactor such as wet-dry cycle and sulfate attack when exposed to tidal area or groundwater level change environment. Partial replacement of cement with mineral admixture is one of the efficient methods for improving concrete resistance against sulfate attack. In this regard, the resistance of concrete with fly ash and slag to sulfate attack was investigated by wet-dry cycle method. The degree of sulfate attack on specimens after different cycles was observed using scanning electron microscopy. The results of compressive strength and percentage of compressive strength evolution factor at various cycling times show an increase in the sulfate resistance of concrete with 60% of fly ash and slag than that only with 40% fly ash. The microstructural study indicates that the primary cause of deterioration of concrete under wet-dry cycle condition is swelling of the sulfate crystal rather chemical attack.
Research about the Crackle-Simulated Coating Technology Applied in the Rice-Straw Board Furniture Surface Decorating
Authors: Xiong Xian Qing , Wu Zhi Hui
Published: July 2011

Under certain conditions, a test about the crackle-simulated coating technology of rice-straw board after sanding its surface, which aims to determinate several indexes include the glossiness of the coating surface, the hardness and adhesion of the film, the ability to resist of denaturing, and the feel of the surface, etc. The result shows that: the technology of rice-straw board crackle-simulated coating is available to the medium density fiberboard furniture. Though the indexes of the hardness and adhesion of the film are slightly low, they are all up to the standard of the nation and the enterprise. Moreover, we have also analyzed the decorating effect of the crackle-simulated coating of the surface, the economic cost, the environmental friendliness and other elements, in order to provide a reference frame to the special coating which is conducted on the furniture surfaces.
Effects of the Low Frequency Electromagnetic Field on the Centerline Macrosegregation of 7075 Aluminum Ingots
Authors: Chen Dan Dan , Zhang Hai Tao , Wang Xiang Jie , Cui Jian Zhong
Published: July 2011

The effects of the low frequency electromagnetic field on the macrosegregation of the 7075 aluminum ingots were investigated. The 7075 aluminum ingots with the diameter of 200 mm were prepared by the conventional direct chill casting and the low frequency electromagnetic field casting (LFEC) processes, respectively. The temperature during casting at steady state was measured, and the mushy region was observed from the temperature contour. The concentrations of the alloying elements were measured by the spectrograph. It was found that the transition region was broadened, but the mushy zone became narrower with presence of the low frequency electromagnetic field. The centerline macrosegregation of the ingots was alleviated by the low frequency electromagnetic casting process.
Modeling and Dynamic Simulation of Tracked Vehicle in Vortex
Authors: Xie Ming Xiang , Wei Yan Ding , Zhou Xiao Jun , Guo Yuan Jing , Tang Fang , Luo Zhu Hui , Li Pei Xin
Published: July 2011

Real-time calculation of dynamics model is one of the key technologies in the driving simulator. A multi-body dynamics model of tracked vehicle was developed using the Vortex software. The sinusoid superposition method was exploited to extend the 2-D road surface spectrum and to establish the 3-D road roughness elevation data in accord with the state standard. Then the elevation data were imported into Multigen Creator to construct the 3-D virtual road. Including the vehicle model, the virtual reality system was created. In the simulation of riding comfort, the responses of the vehicle were obtained when the vehicle traversed under road excitation of D grade with constant speed. The result shows that the system offers good immersion and real-time performance. It is feasible to be applied to the tracked vehicle driving simulator.
Analysis of Characteristics of Potential Mud-Rock Flow in Huyu Valley
Authors: Lv Yi Qing , Liu Hong Fu , Wen Xue Qin
Published: July 2011

Taking potential debris flow in Huyu Valley as research object, the investigation of geological condition in Huyu Valley and different accompanied geological processes has been investigated such as complex topography, natural weathering and source of loose debris produced by the accumulation of human engineering activities, the role of uneven rainfall. With the analysis of potential debris flow characteristics of the Huyu Valley comprehensively, the results showes that the potential debris flow of the Huyu Valley already has satisfied conditions.
Consider the Effect of the Variation of Underground Water Level to the Superstructure with the Pile Foundation in Different Burying Depth
Authors: Wu Li Ming , Wang Zi Jian
Published: July 2011

The buildings are constructed on the slope side, to avoid digging massively fill geotechnical Engineering, according to the slope potential's change, the pile foundation makes not the contour form generally, when the subsoil water level rises or the reservoir stores, partial pile bottom is often under the water level,which causes the ground the supporting capacity and the rigidity to change.Adds it when the structural design “the pile- earth-superstructure” will be separated from the consideration frequently, even if considering it together frequently also often neglects the influence of the water level change on the overall construction.As the accident which according to this design's construction structure the dehiscence or the entire construction collapse sometimes occur. In order to avoid this kind of accident's occurrence, we must make it clear that the influence of the water level change on the structure supporting capacity. Based on this, this article takes some storehouse ashore 8 portal frame construction's pile foundation as an example, through finite element software establish “pile-earth-superstructure” three-dimensional moldel, the model analyzes the pile, the earth and the superstructure internal force and displacement's change under the water level change. The analysis result indicated that the water level change causes the structure the internal force and the distortion increases,particularly the pile foundation exists changes the region highly the superstructure.When construction structural design should be considered fully the influence of the groundwater level change on the superstructure,thus makes the structural design be safer reasonably
Construction of Customer Knowledge Management Platform Based on TRIZ
Authors: Wang Hong , Xie Chuan
Published: July 2011

In this paper, TRIZ and knowledge management, the two instruments solving innovation problems of different thinking modes are combined for the first time to construct Customer Knowledge Management platform. This platform has powerful functions, high efficiency, short response time, good expandability and so on, while its performances will be improved with its application time increasing. The platform can keep on being used with the advent of new assistant innovation instrument and its ability to solve problems can be ameliorated. The key to use this platform is the selection of initial knowledge management system.