bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Structural Fatigue Damage Based on the Superimposed Load Spectrum Method
Authors: Shi Xiao Ling , Xie Ji Long , Zhao Fang Wei , Yu Rong Quan
Published: March 2013

We usually calculate the fatigue damage by superimposed respective injury; the paper brings up the superimposed load spectrum method considering load sequence. It superimposed on the load spectrum of each load and obtained the total damage of total stress time history. Finally, as an example, bolster’s damage is calculated by two ways. By contrast, the damage is larger by former method. The injury results based on the method of superimposed load spectrum is closer to the actual situation. Therefore, the research method presented in this paper can provide a reference for future structural damage.
Numerical Simulations of Uniaxial Compression Properties of SiC/6061 Aluminum Alloy Co–Continuous Composites
Authors: Liao Shu De , Lu Sen Kai
Published: March 2013

The uniaxial deformation properties of a SiC/6061 Al alloy co–continuous composites (CCCs) where both phases are continuous have been studied using the Solidwork Simulation software applied the finite element method (FEM). The simulated results have shown that the composites are relatively anisotropy, 6061 Al alloy matrix and SiC network ceramic exhibit different mechanical behaviour. The ultimate stress is found near the interface of composites. The configuration of SiC has relatively great influence on intensity and distribution of stress in the composite. The material behaves in a nearly bilinear manner defined by the Young’s modulus and an elastic-plastic modulus. The large deformation appears inside 6061 Al alloy matrix. The 6061 Al alloy matrix and SiC can restrict each other to prevent from producing the strain under the load.
The Isothermal Simulation of the Un-Saturated Flow in the Dual-Scale Porous Media
Authors: Lee Yong Jing , Yan Shi Lin , Ye Xin , Feng Zhong Jiang
Published: March 2013

Most of the mold-filling simulation theories for RTM were based on Darcy law and combined with mass conservation equation. Considering the unsaturated region in the experiment, the followings have been done in this paper: (1) first, explaining this un-saturated phenomenon as a sink effect, and amending the saturated filling mold by introducing a sink term to the mass constant equation; (2) second, achieving a simple 1d mold’s unsaturated simulation of the filling process through the compiled software pore-flow.
A New Stress Mathematical Model of Deformation Zone while Straightening Thin-Walled Tube
Authors: Zhang Zi Qian , Yan Yun Hui , Yang Hui Lin
Published: March 2013

As there was no precise theoretical model for predicting the stress of deformation zone while straightening thin-walled tube, some technological parameters depended mostly on the experience of workers and on the results of trials, therefore by means of the membrane shell theory the equilibrium differential equations of stress is obtained firstly, then we analyze the strain of deformation zone, finally lead to a new theoretical model for predicting the stress in the elastic and plastic zone. Subsequently the simulated experiments have been done, the results show that the theoretical calculations coincide well with the simulated results, the errors are within 1％of the calculations, it is testified that the model is correct and efficient for the thin-walled tube straightening.
Direct Electrodeposition of Highly Ordered Au-Cu Alloy Nanowire Arrays
Authors: Zhang Wei , Huang Xin Min , Zhao Yong Jiu , Wu Yu Cheng , Xu Guang Qing , Xu Kang , Li Peng , Zhang Peng Jie
Published: March 2013

Au-Cu alloy nanowires with diameters 50-100nm and lengths of 500nm have been obtained by direct electrochemical deposition.The fabrication of highly ordered Au-Cu alloy nanowires arrays was used as a Anodic aluminum oxide (AAO) template. This template was fabricated with two-step anodizing method. In this paper, we report electrochemical deposition fabrication of Au–Cu alloy nanowire arrays by AAO. Use SEM, TEM can detect morphology of Au-Cu alloy nanowires, And use EDS to analyse the elements.The electrocatalytic activities of the Au-Cu alloy nanowires for the oxidation of ethanol in acidic medium were investigated by cyclic voltammetry.
Effect of High Shear Mixing Parameters and Degassing Temperature on the Morphology of Epoxy-Clay Nanocomposites
Authors: Al-Qadhi Muneer , Merah Nesar , Mezghani Khaled , Khan Zafarullah , Gasem Zuhair , Sougrat Rachid
Published: March 2013

Epoxy-clay nanocomposites were prepared by high shear mixing method using Nanomer I.30E nanoclay as nano-reinforcement in diglycidyl ether of bisphenol A (DGEBA). The effect of mixing speed and time on the nature and degree of clay dispersion were investigated by varying the mixing speed in the range of 500-8000 RPM and mixing time in the range of 15-90 minutes. The effect of degassing temperature on the morphology of the resultant nanocomposites was also studied. Scanning and transmission microscopy (SEM & TEM) along with x-ray diffraction (XRD) have been used to characterize the effect of shear mixing speed, mixing time and degassing temperature on the structure of the resultant nanocomposites. The SEM, TEM and XRD examinations demonstrated that the degree of clay dispersion was improved with increasing the high shear mixing speed and mixing time. The results showed that the optimum high shear mixing speed and mixing time were 6000 rpm and 60 min, respectively. It was observed that the structure of the nanocomposites that have been degassed at 65oC was dominated by ordered intercalated morphology while disordered intercalated with some exfoliated morphology was found for the sample degassed at 100oC for the first 2 hours of the degassing process.
Seasonal Soil Freezing Characters in Daxinganling
Authors: Ding Lin , Liu Yan Jie , Min Yi Mei
Published: March 2013

For understanding the transport of groundwater existing in the seasonal freezing soil，laboratory test and field monitoring (frozen depth、moisture content and ground temperature in five months) were carried out in Daxinganling. A translocation model is built to analyze water behavior. The result shows that thermal conductivity will increase approximately one percent when temperature decreases 1°C. A transition function is used to prevent non-convergence in the numerical simulation. The simulation proves that the modified numerical simulation can reveal the law of moisture and heat translocation, and further offer guidance in practice.
Effects of Processing Techniques on Morphology and Mechanical Properties of Epoxy-Clay Nanocomposites
Authors: Merah Nesar , Al-Qadhi Muneer
Published: March 2013

Proper dispersion of nano thin layered structure of nanoclay in polymer matrix offers new and greatly improved properties over pristine polymers. The degree of nanoclay dispersion and hence the improvements in the physical and mechanical properties depend greatly on the technique used and processing parameters. In this work, 2 wt.% epoxy-clay nanocomposites were fabricated using different mixing techniques to study the effect of mixing methods on the nanoclay dispersion and thus on the enhancement of the properties of the resultant nanocomposites. Three mixing techniques were explored: high shear mixing (HSM), ultrasonication and their combination as well as hand mixing. The effect of mixing techniques on morphology and mechanical properties of the resultant nanocomposites was investigated using scanning electron microscope (SEM), X-ray diffraction (XRD), transmission electron microscope (TEM) and tensile testing. The results of XRD and TEM showed that both exfoliated and disordered intercalated morphology were developed for the nanocomposites synthesized by HSM, while ordered intercalated morphology was observed for samples prepared by sonication. The tensile test results show that among the mixing techniques considered in this study HSM results in the optimum mechanical properties as a whole while hand mixing resulted in the worst physical and mechanical properties.
Influence of Rare Earth on the Peeling Properties of Ultra-Thin Copper Foil with Carrier
Authors: Deng Geng Feng , He Gui Rong , Huang Jue Qi , Xu Peng
Published: March 2013

In this paper, the peeling strength between ultra-thin copper foil and carrier is improved by some rare earths used as additives during the formation of the stripping layer of H-G alloy. The effect of different rare earth and their different contents on the stripping property of ultra-thin copper foil with carrier when they are added in the H-G plating solution is investigated, and the influence of rare earth on the cathodic polarization curves and cyclic voltammetry curves of H-G alloy during its electrodeposition is analyzed too. Results show that rare earth elements of La, Sm, Y and Ce increase the peeling strength between ultra-thin copper foil and carrier to a certain extent and the peeling strength is increased from 0.13 kgf •cm-1 to the range of 0.16 ~ 0.20 kgf •cm-1. Different rare earth contents also have impact on the peel strength and surface property of ultra-thin copper foil with a carrier support, in which the optimum adding amount of La is 0.1 g •L-1. Electrochemical test results show that the addition of rare earths can reduce the degree of the plating solution’s polarization, accelerate the electrode reaction speed, increase the alloy reduction capacity, promote alloy’s co-deposition, and improve the bonding strength between alloy layer and substrate, thus the peeling strength between ultra-thin copper foil and carrier is enhanced.
Microstructure and Wear Properties of TiC/Fe-Based Composite Coating Prepared by PTA Weld-Surfacing Process
Authors: Zhao Zhong Li , Dang Kai Fang , Liu Jun Hai , Wu Da Ming , Liu Ying , Yu Hai Peng , Zheng Xiu Ting
Published: March 2013

The TiC/Fe-based composite coating was fabricated by plasma transferred arc (PTA) weld-surfacing process on substrate of Q235 steel with the mixture of ferrotitanium, ferrochromium and ferrosilicium powders. The microstructure and wear properties of the coating were investigated by means of X-ray diffraction (XRD), scanning electron micrograph (SEM), energy dispersive X-ray analysis (EDS), microhardness test and wear test. The results show that the coating consists of TiC, (Cr,Fe)7C3 and austenite. The composite coating is metallurgically bonded to the Q235 steel substrate. TiC particles formed by PTA weld-surfacing process presented cubic or “dendrite flower-like” morphology. The wear-resisting property of the coating was greatly improved compared with the substrate. The coating has excellent adhesive wear and grinding abrasion resisting force.
Microstructures and Wear Resistance of Si-Al-Y Co-Deposition Coatings on γ-TiAl Alloy
Authors: Li Yong Quan , Xie Fa Qin , Wu Xiang Qing
Published: March 2013

Si-Al-Y co-deposition coatings on γ-TiAl alloy were prepared by pack cementation process at 1050°C for 3 h, Scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDS), X-ray diffractometer(XRD) and microhardness tester were employed to investigate the surface morphologies, surface element distributions, microstructures, phase constitutions and microhardness of the coatings. Friction-wear tests of the γ-TiAl alloy substrate and the coatings were conducted in air at ambient temperature. The results show that the coating prepared by co-depositing Si-Al-Y had a multiple layer structure: the outer layer was composed of TiSi2, TiSi, Ti5Si4, Ti5Si3, the middle layer was composed of TiAl3, TiAl2, and the inner layer was Al rich layer. The microhardness of the surface is up to 1538HK0.49.The wear mass loss is only one half as much as that of γ-TiAl matrix, and the wear resistance increases significantly.
Electrodepositing Ir Film at Constant Current in NaCl-KCl Molten Salts
Authors: Qian Jian Gang , Li Hai Ting , Li Peng Rui , Zhao Tian
Published: March 2013

In this study, the dense and well-integrated Ir films were electrodeposited on Pt substrate at a constant current process in the NaCl-KCl molten salt system containing IrCl3. The morphology and constitution of the Ir films at different process conditions were examined by scanning electron microscope (SEM), energy dispersive spectroscope (EDS) and X-ray diffraction (XRD) respectively. The results showed that IrCl3 concentration had significantly influenced the surface morphology of the Ir film. The particles of the deposition film surface became lager with increasing the fraction of IrCl3 and gradually decreased with increasing the temperature. However, the film quality decreased due to the formation of some tiny holes when further increasing the temperature. The particle size decreased gradually with the increase of deposition current density. The addition of CsCl could not only reduce the molten salt temperature but also increase the deposition rate of Ir.
Ni-P-Diamond Composite Coating on Friction Shims
Authors: Chen Hua , Sun Hai Ying , Jia Su Qiu
Published: March 2013

Ni-P diamond particles (20μm) composite coating on friction shims were prepared by electroless plating. Morphology and phase composition of the composite coating were measured by SEM with EDS and XRD. The friction coefficient of the coating was test with scratch test. The results showed that diamond particles distribution was uniform and not stacked by two steps for 10 min. The diamond particles were half embedded in the Ni-P substrate. The element of the coating was Ni,P,C and the phase composition was Ni and diamond. Adhesion of the composite coating was higher than that of the Ni-P coating. Friction coefficients of the Ni-P coating and Ni-P composite coating were 0.47 and 0.18. Half –naked diamond particles played a pinning role and prevented from wear of the coating to get the big friction coefficient and good wear resistance. This Ni-P composite coating on friction shims would improve friction shims technology and realize the production of localization of friction shims.
Microstructure Characteristic of Laser Cladding Ceramic Layer on High Cr Cast Steel Surface
Authors: Li Yi Shan , Han Bin , Gao Cai
Published: March 2013

The Al2O3 gradient ceramics coating was cladded on the high Cr cast steel by 5KW crosscurrent CO2 laser with Ni-based alloy which was used as transition metal in this experiment. The microstructure is analyzed with optics microstructure analyzer and the crystal grain characteristic is studied. The results show that the microstructure of laser cladding layer contains the plane crystal zone which grows along the substrate, the cellular crystal zone, the dendritic crystal zone and the surface equiaxed cryatal zone. The microstructure of the coating compared with the substrate is extremely fine, and the microstructure of multi-layer cladding presents stratification. The phase composition of the cladding layer is composed primarily of NiAl intermetallic compound, also includes γ-FeNi and a little Ni3Al compound. The Al2O3 particles that some present the single crystal form and some accumulate in together, play the dispersion strengthening role in the coating material. The massive twin crystals and the dislocation pile-ups are found to exist in the cladding layer.
Effects of Friction Load and Ultrasonic Vibration on the Tribological Properties of Al2O3/Al2O3 Ceramic Friction Pairs under Liquid Paraffin Lubrication
Authors: Dong Xin Yu , Qiao Yu Lin , Zang Yan , Cui Qing Sheng
Published: March 2013

The effects of friction load and ultrasonic vibration on friction reduction and anti-wear properties of Al2O3/Al2O3 ceramic frictional pairs under oil lubrication were investigated by a modified MFT-R4000 reciprocating friction and wear tester. The mechanism of friction reduction and anti-wear under ultrasonic vibration was discussed. The results showed that, the ultrasonic vibration could influence the friction reduction and anti-wear properties of Al2O3/Al2O3 ceramic friction pairs due to it could reduce the stress between the friction pairs and destroy the oil film on the surface of samples. When the friction frequency was 2Hz, the ultrasonic vibration could reduce the friction coefficient within experiment load range. When the loads were 70N, 80N, 90N and 100N, the average friction coefficient were reduced by 16.1%, 14.5%, 9.7% and 2.6%,and wear volume of frictional pairs decreased 35%、32%、31% and 12%.
Research on the Microstructure and Performance of Co-Based Alloy Surfacing Layer
Authors: Wang Hong Mei , Liu Chang Jun
Published: March 2013

With the help of applying the welding method of DC transverse magnetic field plasma arc surfacing, the powder of Co-based alloy is built up welding on surface of low carbon steel, the refinement effect of primary and secondary crystal structure inflicted by the magnetic field is confirmed through hardness test, wear resistance test, metallographic test and XRD analysis. And study systematically the law of DC transverse magnetic field influencing the surfacing layer metal hardness and wear resistance. The results show that the mechanical properties of surfacing layer achieve the best value when appropriate overlaying welding current match with magnetic current. "Magnetic blow" can be improved with the addition of transverse magnetic field, improving the stability of overlaying welding arc process.
Simulation of Microstructure Evolution on Copper, Aluminum and Alloy during ECAP
Authors: Guo Ting Biao , Zhao Jun Yuan , Ding Yu Tian , Li Hai Long , Liu Bo
Published: March 2013

The microstructure evolution of different stacking fault energy metal materials, copper, aluminum alloy and magnesium alloy during ECAP, were investigated based on the finite element simulation software DEFORM-3D. Analyzed the effect on the microstructure of deformation speed, extrusion passes and stacking fault energy. The results show that, the grain size is decreased with the pass number increasing, and deformation speed has no obvious effect on the microstructure. The high SFE metal, aluminum, shows a finer grains than the medium SFE metal, copper.
Statistical Study on Correlation between Design Variables and Shape Errors in Flexible Stretch Forming Process
Authors: Seo Young Ho , Yoon Jun Seok , Kang Beom Soo , Kim Jeong
Published: March 2013

In order to reduce the elastic recovery of a sheet material and eliminate a great number of solid dies used in the forming process of various shapes, a flexible stretch forming process (FSFP) is considered in this study. Especially, the relationship among design variables, such as the punch size, objective radius of curvature, and elastic pad thickness is quantitatively evaluated to find out their respective influences on the shape errors of a formed sheet plate using the statistical method based on the FE simulation result planned by the three-way factorial design. The shape errors are divided into two types based on the material behavior according to the widthwise- and tensile- directions. The correlations of the shape errors and the design variables are estimated through the Pearson correlation analyses. The punch size has a strong positive linear correlation with the widthwise- and tensile- shape errors, and the correlation between the objective curvature radius and tensile-direction shape error is weak and negative. Although the effect of the elastic pad thickness is less than those of the other variables, it prevents effectively surface defects. Subsequently, the mathematical model is assumed to clarify their relationship. Two regression equations are estimated in terms of the design variables regarding the widthwise- and tensile- shape errors. The shape errors could be inferred by the assumed model in the particular combination of the design variables; then, the acceptable punch size and elastic pad thickness can be determined according to the objective curvature radius.
Surface Roughness Analysis of Metal Spun Parts
Authors: Šugár Peter , Šugárová Jana , Petrovič Ján
Published: March 2013

The paper brings the results of roughness analysis of formed part produced by CNC multi-pass conventional metal spinning. The influence of the spindle speed, workpiece geometry and planar anisotropy of the blank on the formed part roughness was studied. For experiment design, an orthogonal array L27(313) was used and ANOVA (Analysis of Variance) was carried out. Based on the results it is determined that the higher spindle speed leads to rough surface finish. The surface roughness measured in different areas of experimental samples (corner R10, conical area, cylindrical area) indicates that the worst surface finish is in the conical area. Roughness in different directions refer to the sheet rolling direction shows minimal differences.
Numerical Simulation of Large-Sized Pure Aluminum Rod under Multi-Pass ECAP
Authors: Zhao Xiao Lian , Zhao Ning Ning , Chen Na
Published: March 2013

In order to obtain the bulk ultra-fine grain materials with excellent performance under the conditions of severe plastic deformation, the law curves of squeeze pressure, stress and strain of the extrusion process on large-sized pure aluminum rods had been gotten by the finite element simulation of 6-pass ECAP. With the increasing of extrusion passes, the maximum extrusion load increases significantly and the distribution uniformity on the values of equivalent stress and strain improves. So the multi-pass equal channel angular pressing can achieve good effect of grain refinement and improves the distribution uniformity of grain-size.
The Mathematic Model of Deformation Resistance of S50C Medium Carbon Steel in Hot Rolling Process
Authors: Liang Jing Long , Feng Yun Li , Yin Jin Zhi , Cang Da Qiang , Li Hui
Published: March 2013

A test study of deformation resistance of S50C medium carbon steel in hot rolling process was conducted by using Gleeble 3500 Thermal-mechanical testing machine. The relationship of deformation resistance with different deformation temperature and deformation rate and deformation degree was analyzed through the stress-strain curve of S50C medium carbon steel which measured in the test. The results show that the deformation resistance increase with decrease of deformation temperature and increase of deformation rate and deformation degree. The math model of plastic deformation for metal of tested steel is established by using 1stopt software with multi-component non-regression. The model is proved has good curve fitting characteristics though a regression analysis of the model, it can be used provide theory basis for the formulation of rolling process and calculation of the mechanical parameters.
The Identified Principle of Machining Conditions and its Application in NC Machining
Authors: Li Qiang , Lu Lin Ping
Published: March 2013

Based on the analysis of NC machining precision, aiming at the influence of dynamic factors in NC machining system, the identified principle of machining conditions is proposed, also, approach of identified machining conditions in errors compensation to control increment of dynamic dimensions is put forward. The practical machining result shows that the original precision of machine and the machining precision of parts are improved.
Experiment Studies of Nd:YAG Laser Assisted Dressing Technique for Metal-Bonded CBN Grinding Wheel by Crankshaft Grinding
Authors: Zhang Guo Jun , Li Ming Zhen , Huang Yu , Zhang Shang
Published: March 2013

Superabrasive grinding wheels are widely applied in today’s grinding industries due to its advantages such as long tool life, low wearing effect, fine dimensional stability etc. Dressing is one of most important processes of grinding operation that largely influences the workpiece quality and manufacturing productivity. However, dressing of superabrasive grinding wheel is low efficiency by conventional dressing method. In this paper, an a flashlamp-pumped pulsed Nd:YAG laser assisted dressing technique for metal-bonded CBN grinding wheel is developed, and experiment results demonstrate the proposed laser-assisted dressing technique is greatly improving dressing efficiency, reducing dressing time, extending the life of diamond dresser comparing to conventional dressing method. Key paramters of straintness, cylindricity and roughness of Crankshaft between before and after dressing operation is contrasted, the results proves that in the practical grinding process, the laser assisted dressing technique has similiar quality in contrast to conventional diamond dressing method and highly promotes the dressing efficiency.
Study on Micro-Topography Characteristics of EDM Surface
Authors: Ding Hai Juan , Wang Xiao Xia , Xia Guang Lan , Feng Ping , Li Xiao Hai
Published: March 2013

This paper is based on the experimental observation. The micro-topography characteristics of electrical discharge machining (EDM) surface were studied. The results show that the EDM surface is made up of three-dimensional craters and hard protrusions overlapped alternately which distribute randomly and non-directionally. The pulse energy has significant effect on the forming of EDM surface profiles, and peak current and pulse width are the main factors.
Recent Development of Parameter Optimization for Metal Cutting and Grinding Processes
Authors: An Li Bao , Lu Chun Guang
Published: March 2013

Metal cutting indicates a specific category of processes in which unwanted material is removed from workpeice by single- or multi-point cutting tools for making products meeting prescribed specifications. Parameter optimization in metal cutting plays an important role in satisfying quality requirements of machined parts at low production cost or time. It requires optimal selection of cutting speed, feed rate, depth of cut, and the number of passes. A brief review of recent progress on the optimization of cutting parameters is introduced in the present work. Some new machining practices expending in recent years are involved including hard turning, dry cutting, high speed machining, machining of difficult-to-machine materials and composites. Modeling skills for creating optimization models and optimization techniques for solving optimal or near-optimal solutions are summarized and analyzed.
Preparation of Nitrogen Hybrid Ordered Mesoporous Carbons from Melamine-Phenol-Formaldehyde Resoles by Soft-Template Method
Authors: Zhang Wei , Zhang Yan , Liu Yu Jian
Published: March 2013

Nitrogen hybrid ordered mesoporous carbons (N-OMC) were prepared by the soft-template method with melamine-phenol-formaldehyde resoles (MPF) as the precursors and triblock copolymer F127 as a soft-template. FT-IR spectra analysis demonstrated that nitrogen was incorporated into the mesoporous carbons with C-N covalent bonds. The effect of molar ratio of phenol to melamine on the pore structure and textural properties was discussed by small angle X-ray scattering, nitrogen adsorption measurements, and transmission electron microscopy. The results show that the degree of pore order decreases with the increasing of nitrogen content. The N-OMC with 3.39 wt% nitrogen has the highest specific surface areas (573m2/g) and best ordered mesostructure.
Influence of 0 Degree to the Shoulder of the Friction Stir Welding on AA 6063 and AA 7075
Authors: Pumchan Wichai
Published: March 2013

The main aim of this research study 0 degrees to the shoulder to the welding of aluminum alloy rolled grade 6063 and 7075 were made by a friction stir welding. The variables welding speed to determine the tensile strength and macro-structure of specimens. The results were summarized. Variables to make major changes to the weld is incomplete and the defects in the weld. When the welding speed is not reasonable. Shoulder is available to heat the material to make two kinds of weakness. The top surface is not smooth still the scale. On both of materials have fin. Defects in the weld is still going on in the shoulder of tool to 0 degrees to provide maximum strength is 180 MPa at 1000 rpm with a welding speed 50 mm / min
Research on the Usability of the Defective Grid Structure
Authors: Feng Yan Ting , Li Zhong Wei , Zhao Ji Feng
Published: March 2013

Regarding dangerous defects such as cracks and lack of fusion in the joint weld of conical head and tube of grid structures and presented problems in NDT, research on usability of the defective grid structure was carried out through theoretical computations and experimental tests of mechanical properties of defective welds with specification of Φ60×3.5mm. Specific advice concerning quality control of the joint weld is given.
Dissimilar Friction Stir Spot Welding without Key Hole between AZ31B Magnesium Alloy and 5052 Aluminum Alloy
Authors: Wang Xi Jing , Guo Ting Kai , Zhang Zhong Ke , Wang Pei Chung , Shi Ji Peng , Wu Yu Lian , Lu Yong Xin
Published: March 2013

To study the impact of the welding process parameters on the spot weld surface molding, mechanical performance and the stir zone microstructure, we use friction stir spot welding without keyhole method which designed and developed by ourselves to carry on the lap welding between 1mm sheet of AZ31B magnesium alloy and 3mm sheet of 5052 aluminum alloy with magnesium on top and aluminum bottom. The result of the orthogonal test shows that the shoulder friction time have a greater impact on the forming of the surface of the welding joint; When the rotating speed of 1000 r/min, shoulder friction time of 4s, pin length of 3.5mm, the tensile shearing force of the welded joint achieves its maximum value of 2.46 KN.Through observating the microstructure of the welding joint’s section stirring zone, we found the typical joint microstructure of Dissimilar metal. Through analyzing the microstructure of the tensile fracture, we found that fracture was cleavage fracture.We also found the fracture mechanism of the welding joint was cleavage fracture in microcosm but brittle fracture macrocosm.
Optimization of Parameters and Research on Joint Microstructure of Resistance Spot Welding for 316 Stainless Steel
Authors: Liu Hui , Xu Xue Dong , Zhang Xiao Qing
Published: March 2013

The experimental investigations on resistance spot welding are presented for 316 stainless steel. The influence of spot welding parameters (welding time, electrode force and welding current) on the tensile shear load and the diameter of nugget have been researched, based on an orthogonal test and analysis method. The results show that welding current has significant influence on the tensile shear load and diameter of nugget, and then is electrode force, welding time in turn. The optimum parameters are as follows: welding time is 5 cycles, electrode force is 3.5KN and welding current is 5.5KA. And the maximum tensile shear force of joint is up to 13.55KN.
Characteristics Evaluation of Weld Metal Zone Welded with Various Repair Welding Filler Metals
Authors: Jeong Jae Hyun , Won Jong Pil , Park Dong Hyun , Lee Sung Yul , Kim Yun Hae , Moon Kyung Man
Published: March 2013

Recently, the fuel oil of diesel engine of marine ships has been changed with heavy oil of low quality as the oil price is getting higher and higher. Therefore, the wear and corrosion against all parts of the engine, such as cylinder liner, piston crown, and spindle and seat ring of exhaust valves has predominantly increased due to its consumption. Thus, the repair welding of the piston crown is a unique method to prolong its life in a economical point of view. In this case, filler metals having a better corrosion and wear resistance are mainly being used for repair welding. However, the piston crown on the ship’s job site is often actually being welded with mild filler metals. Therefore, in this study, the mild filler metals, such as E5016, E1216, and E2316, were welded to the SS401 steel as the base metal, and the corrosion properties of their weld metal zones with and without post weld heat treatment were investigated with some electrochemical methods in 0.1% H2SO4 solution. The weld metal zone welded with E1216 filler metal exhibited the best corrosion resistance among the filler metals with irrespective of heat treatment, however, its corrosion resistance was somewhat decreased due to the post weld heat treatment(annealing:625oC, 2hr). In particular, the weld metal of E2316 exhibited relatively a good corrosion resistances by the post weld heat treatment.
Experimental Investigation on Femtosecond Laser Ablation of Polycarbonate
Authors: Qi Li Tao , Hu Jin Ping
Published: March 2013

In this paper, experimental investigations on femtosecond laser (pulse duration:164 fs, wavelength:780 nm) micromachining of polycarbonate have been carried out in air. The lateral and vertical machining precision was evaluated by scanning electron microscopy and profilometer. The morphological changes were observed by scanning electron microscopy. The ablation mechanism varied with the laser pulse energy was discussed. The diameter and depth of the ablated crated are influenced by the laser pulse energy and the number of laser pulses. The relation between the diameter and ablation depth of the crater and the key parameters of femtosecond laser is obtained. Femtosecond laser micromachining of polycarbonate have a potential application of the fabrication of polycarbonate-based devices.
Characterization of TC17 Titanium Alloy Treated by Square-Spot Laser Shock Peening
Authors: Cao Zi Wen , Gong Shui Li , Gao Yu
Published: March 2013

Laser shock peening (LSP) is widely known as a cold-worked surface treatment, and this technology has been to greatly improve the fatigue life of many metallic components. Our works focused on laser shock peening with Nd: glass laser system (pulse duration 30ns) and square laser spot size of 4mm×4mm for TC17 titanium alloy. Surface morphology, residual stresses and fatigue performance had been studied for TC17 alloy specimens and blades processed by LSP treatment. The results show that plastic strains in shocked dents become more homogeneous than ones produced by original circle spot with gaussian energy distribution. Surface residual stresses which measured using x-ray diffraction method showed different characteristic as varying specimen thickness, and LSP with overlapping ratio of 8% provided uniform residual stresses on peened surface. Low fluence peening which was implemented at borderline of peened surface was effective to diminish the stress gradient. Compared with mechanical shot peening, LSP attained smoother surface, lower microhardness and better fatigue performance. In a word, Square-spot LSP is an excellent way to improve fatigue life of titanium blade.
Analysis of Elemental Segregation in a Microalloyed Cast Steel
Authors: Zhao Jing Wei , Jiang Zheng Yi , Wei Dong Bin
Published: March 2013

Quantitative investigation is made on the elemental segregation in different zones of a heavy microalloyed cast steel by energy dispersive X-ray spectroscopy. It is demonstrated that C shows serious segregation tendency than that of Mn and Si, and the degree of C segregation in the surface zone is higher than that in the central zone. C enrichment is generally observed at both dendrite arm and grain boundaries, and more C segregation at dendrite arm boundary in contrast to that at grain boundary is found in this steel. The distribution of C concentration shows a decreased trend from root to tip along the dendrite arm boundary. The C concentration at trigeminal boundary intersection shows higher level than that at other position of the grain boundaries.
Mineral Processing Experiment of Copper Mineral in Yunnan Province
Authors: Nie Yi Miao , Zhang Jin Xia , Dai Qi Hui
Published: March 2013

Based on the chemical analysis and mineral composition research, a series condition tests were done with ore grade 1.45%.The optimum conditions were grinding fineness -0.074mm65%, collector as butyl xanthate- Ammonium aerofloat butyl(3:1) with 100g/t ,activator as sodium sulfide 200g/t,foaming agent as 2#oil of magnetite 30g/t. The result of tests showed that the grade of copper concentrate and the copper recovery are 8.98% and79.50% by adopting a circuit of one rough flotation, two scavenger.
Analysis of Tight Gas Reservoir Forming Condition in Gulong-Changjiaweizi Region, Northern Songliao Basin
Authors: Zhang Xue Juan , Lu Shuang Fang , Huang Wei , Zhang Lei
Published: March 2013

This paper makes systematic analysis of geological factors of natural gas accumulation in Denglouku formation of Gulong-Changjiaweizi region, including reservoir characteristics, gas source condition, source-reservoir relationship, structural condition, etc. It turned out that K1d2 in Gulong-Changjiaweizi region is generally typical tight sandstone reservoir with low porosity and permeability due to the poor physical properties. The gas source rock of K1d2 formation has larger gas producing capacity.The relationship between source rock and reservoir shows as interbed interfinger or directly contiguity contact, which is beneficial for large-area gas accumulation. The gas generation area of source rock in this region is always in the center and slow downdip direction of Gulong depression with a smaller dip angle on the adjacent tight sandstone reservoir, where faults are rare. The result of comprehensive analysis shows that K1d2 formation in Nothern Songliao Basin and its neighboring layers could be considered as a favorable target of the tight gas reservoir study in Northern Songliao Basin due to its favorable geological conditions of deep basin tight gas reservoir generation, such as tight reservoir, sufficient gas source, communicating source-reservoir relationship and constant flattened structure.
Geological Evaluation of Puzzle Reservoirs in Putaohua Reservoir of Weixing Oilfield
Authors: Zhang Shi Qi , Zhang Mei Ling , Bao Yi , Zeng Ke
Published: March 2013

Low energy sedimentary environment with weak water power and high salinity of formation water are the main requirements of low-resistance oil layer development. Whereas part of formation penetrated by hydrocarbon migration, which shows larger bend degrees of conductive tunnels in formation and higher resistivity measurement due to the oxidization of the residual crude oil, forms high-resistance water layer. Because of the complexity of accumulation conditions, these two difficult reservoirs exist in Putaohua reservoir of Weixing oilfield widely. Combined with these accumulation regularities, this paper analyzes and summarizes the complex oil and water distribution characteristics, provide recognition means, so as to enhance the logging evaluation precision of these two difficult reservoirs effectively.
Hydrocarbon Accumulation Characteristics in Cretaceous System Hailaer Basin
Authors: Yu Ying Hua , Yuan Hong Qi , Zhong Xiang Li , Qiu Xue
Published: March 2013

Based on the sequence stratigraphy principle, reservoir forming elements has been detailed analysis in Cretaceous system of Hailaer basin, by using core, logging and 3-D seismic data. The study shows that the thick mudstone layer in the transgressive systems tract of the super-sequence is good regional source rock .and regional caprock, meanwhile the sandbody developed in transgressive systems tract and highstand systems of the super-sequence become the regional reservoir of depression. The main hydrocarbon migration pathway is uncomformable surface, fault, frame-sandstone, or that the hydrocarbon born in source rock went into the sandstone of sublacustrine fan directly, and then, lithologic reservoirs was formed.
Synthesis of Chitosan-Stabilized Gold Nanorod Using Tripolyphosphate
Authors: Guan Hua Nan
Published: March 2013

An improvement in the previously reported seed-mediated chemical synthesis of gold nanorods (GNRs) is reported. Gold nanoparticles were prepared by reducing gold salt with a polysaccharide, chitosan, in the presence of tripolyphosphate (TPP). The obtained gold nanoparticles were characterized with UV-vis spectroscopy and transmission electron microscopy. The study shows that TPP plays an important role in the formation of GNRs.
Preparation of Ammonium Tungstophosphate-Calcium Alginate Composite Adsorbent and its Adsorption Properties of Rubidium
Authors: Huang Xian Jiang , An Lian Ying , Zhao Xian Yin , Chen Xiao Qing
Published: March 2013

A spherical composite adsorbent AWP-CaALG was prepared by the calcium alginate(CaALG) and ammonium tungstophosphate(AWP). The composite adsorbent was characterized by XRD, FT-IR and TG-DTG-DTA, it proves that the crystal structure of AWP isn’t destroyed and the adsorption ability of the composite adsorbent can be retained up to 120°C. Effects of adsorbent dosage, adsorption time, pH, temperature, concentration of Rb and K were investigated. The results show that the adsorption capacity of composite adsorbent to rubidium is 20.64mg/g.The adsorption equilibrium is gained after 24h. When the concentration ratio of K to Rb is 16, the adsorption rate of Rb can still be up to 94.1% and the Rb/K separation coefficient is 86.
Fractal of Grain Distribution in Sintered Ore with Variable Brazil Iron Ore
Authors: Zhang Yu Zhu , Zhang Qing Jun , Sang Rong Li , Chen Ying , Li Yuan Liang
Published: March 2013

The low silicon sintered ores are prepared, where C content is 3.3%, 3.5%, 3.7%, 3.9% and 4.1%, respectively. Their metallurgical properties are also measured. The results state that the low temperature reduction degradation property in low silicon sintered ore is to achieve the best when the carbon content was 3.7%. With increasing carbon content, it has a trend that the low silicon sintered reducing gradually become variation. In this range of carbon content, softening initial temperature exceed 1230 oC, the softening interval is less than 120 oC, so suitable C content are helpful to improve metallurgical properties for low silicon sintered ore.
The Investigation between Sedimentary Facies of Middle Cambrian and the Characters of Volcanic Rock, in Wenshan, Yunnan Province
Authors: Huang Jian Guo , Han Run Sheng , Ren Tao , Li Zhi Qiang
Published: March 2013

The Middle Cambrian Tianpeng Formation volcanic rock, which was found in Baishiyan area in Wenshan recently, is the typical basalt. Through the research of Tianpeng Formation Sedimentary Enviroment and analysis of the geochemistry which includes the major elements, REE and Trace Element in the volcanic rock, SiO2 is 45.78-54.88%, total alkali (alk)=1.22-4.97 and K2O/Na2O=0.03-0.53, we can say that it should be tholeiite series. ∑REE=48.60-157.11ppm,LREE/HREE7.56-9.48,δEu0.40-1.05.REE distribution patterns show oblique to the HREE side and enrichment in LREE , the Eu anomaly is not obvious. We can see from the Trace Element Correlogram that the volcanic in this area is formed from the intiaplate basalt environment. The Tianpeng Formation in this area is clastic rock in a shallow sea and a basin facies and also is the deposit of flysch-simiflyschoid of siliceous and carbonate rock. Also, it deposit with the some undercompensation basin like laminated striation structure. All of those reflect that the structure background of the Middle Cambrian in Wenshan area has strong tensive back-arc spreading.
Compressive Behavior of Spark Plasma Sintered CNT Reinforced Al2124 and Al6061 Nanocomposites
Authors: Saheb Nouari
Published: March 2013

In the present study, compressive behavior of CNT reinforced Al2124 and Al6061 nanocomposites was investigated. The powders were sonicated for 30 minutes then ball milled at 200 rpm for 1 hour under argon environment. The ball milled slurry was dried and again was milled under same conditions for 15 min to disperse the agglomerated particles. The prepared powders were spark plasma sintered at 35 MPa and 450oC. Sintered specimens with final dimensions of 6 mm diameter and 12 mm length were used as standard specimens for compression tests carried out at a compression rate of 0.5 mm/min. The effect of CNT addition on the compressive modulus, percentage compression, and compressive strength was investigated.
Facile Preparation of Polylactic Acid/Ketoconazole Composite Microspheres by Oil/Water Solvent Evaporation Method
Authors: Zhang Yan Hong , Wang Yan , Kong Xian Chao , Cheng Qian Ke , Yang Xi Yuan , Wang Qing Wen
Published: March 2013

In this study, polylactic acid(PLA)/ketoconazole(KCZ) composite microspheres were prepared by oil/water solvent evaporation method. Those drug-loaded microspheres were characterized in morphology using the scanning electron microscope (SEM). Fourier transform infrared spectroscopy (FT-IR) was used to determine the chemical functional groups in the sample and to analysis whether a chemical reaction occured between PLA and KCZ. The thermogravimetric spectra of PLA and PLA/KCZ microspheres were used to analyse the influence of KCZ on the thermal decomposition mechanism of PLA. Crystallinities of the KCZ and PLA/KCZ were analyzed by X-ray diffraction analysis (XRD).
Effects of Solid Content on Properties and Structure of PMN-PZT Green Body by Gelcasting
Authors: Zhou Ping , Du Jing Hong
Published: March 2013

The piezoelectric ceramic of PMN-PZT was prepared by gelcasting using N-hydroxymothl acrylamide(NMAM) as monomer. The green bodies with different microstructure and properties were obtained by changing solid contents of slurry. The effects of solid volume fraction in slurries on properties of PMN-PZT green bodies were investigated. The results that green shrinkage reduced from 5.95% to 1.47%, the green density increased from 3.51g/cm3 to 4.69g/cm3, and green bending strength increased firstly then decreased when solid content of slurry changed from 45vol% to 60vol%. SEM photographs revealed thatSuperscript text the green body had a uniform microstructure and few agglomerates when the solid loading was 50vol%.
Preparation of PMAM-B-PNVP and its Hydrolysate by RAFT Polymerization: Structure Characterization and its CO2 Permeation Performance
Authors: Shen Jiang Nan , Li Juan , Jiang Ting Ting , Ruan Hui Min
Published: March 2013

Macromolecules chain transfer agents (MCTA) were synthesized through the reversible addition fragmentation chain transfer polymerization (RAFT) by using S-l-Dodecyl-S′-(α, α′-dimethyl-α-acetic acid) trithiocarbonate(MTTCD), S, S′-bis (2-hydroxyethyl-2′-dimethylacrylate) trihiocarbonate (BDATC), 2-cyanoprop-2-yl dithiobenzoate (CPDB) as the chain transfer agents, methacrylamide (MAM) as the first polymerization monomer. The results showed that the structures of the end-group of dithiocarbamates had signiﬁcant effects on the activity of dithiocarbamates for the polymerization of PMAM. The derived block copolymer (PMAM-b-PNVP) was prepared by using the above mentioned polymer as macromolecular RAFT agent and NVP as the second polymerization monomer. N-vinyl-γ-sodium aminobutyrate-sodium methacrylate copolymer (VSA-MSA) containing -NH2 and -COOH as the CO2 facilitated carrier, a kind of new fixed carrier membrane material for CO2 separation, was synthesized by hydrolysis of the resulted PMAM-b-PNVP. The chemical composition and structure of PMAM-CTA, PMAM-b-PNVP, MSA-VSA were analyzed by FTIR, 1HNMR and DSC, the molecular weight and polydispersity index were analyzed by GPC. The Relative molecular mass of polymer was controllable. The polydispersity index (1.2~1.3) of the obtained polymer was narrow via using MTTCD and BDATC. The VSA-MSA/PS composite membranes were prepared. The CO2 and N2 permeation performance were tested at different pressure. The results showed that the resulted composited membrane had a CO2 permeation rate of 1.2×10-4 cm3 (STP) cm-2s-1cmHg-1 and a N2 permeation rate of 8.57×10-7 cm3 (STP) cm-2s-1cmHg-1 and an ideal CO2/ N2 selectivity of 140.02 at a feed gas pressure of 7.6 cmHg and 30 °C.
Synthesis of Cellulose-Graft-Poly (L-Lactide) via Ring-Opening Polymerization and Degradability Research
Authors: Dai Lin , Xiao Shu , Qinshu Bai Chuan , He Jing
Published: March 2013

Cellulose-graft-poly (L-lactide) (Cellulose-g-PLLA) was prepared in homogeneous conditions. The polymer was successfully synthesized via ring-opening polymerization (ROP) by using 4-dimethylaminopyridine (DMAP) as an organic catalyst in an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl). The structure of the polymer was characterized by 1H NMR, FT-IR, TGA, WAXD and TEM. The TEM micropicture revealed that the morphology of polymer dissolved in DMSO is globular. Degradability of the polymers was evaluated by the soil burial test. From the correlation analysis, it was revealed that degradability decreased with a further increase of the extent of grafting.