bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Microstructure and Properties of Aged Cu-Ti-Zr-RE Alloy
Authors: Cao Xing Min , Zhu Yu Bin , Guo Fuan , Xiang Chao Jian
Published: September 2009

Electrical conductivity, tensile strength and micro-hardness of Cu-3.5wt.%Ti-0.1wt.%Zr-RE alloy were investigated after optimizing technics of plastic deformation and the heat treatment. The results show that good combination of the physical and mechanical properties, such as tensile strength 1160 MPa, micro-hardness 335 Hv and electrical conductivity 15 IACS% can be obtained on peak aging at 420°C for 7 h. Maximum strength was associated with the precipitation of metastable, ordered and coherent β/ (Cu4Ti) phase on peak aging. Then the strength decreased due to the precipitation of β (Cu3Ti) phase in alloys overaged.
The Study of Ultrasonic Dynamic Elastic Modulus of TiNiFe Shape Memory Alloy in Heating Process
Authors: Gao Xiao Peng , Liu Fu Shun
Published: September 2009

The phase transformation characteristics, the dynamic elastic modulus and the static tensile elastic modulus of Ti50Ni47.5Fe2.5 alloy were investigated. It is found that, the two mutations in the dynamic elastic modulus is caused by reverse martensite phase transformation and austenite phase transformation respectively; Static tensile test can not reflect the intrinsic elastic modulus when the test temperature is close to martensite transformation temperature(Ms). The static elastic modulus and the dynamic elastic modulus have the same trend when the test temperature is enough higher than Ms.
Structure and Photoluminescence Investigations of Self-Organized InAs/GaAs Quantum Wires
Authors: Kong Ling Min , Zhang Cun Xi , Wang Rui , Wang Shi Lai
Published: September 2009

Self –organized InAs quantum wires (QWRs) were fabricated on the step edges of GaAs (331)A surface by molecular beam epitaxy (MBE). The atomic force microscopy (AFM) results show that the lateral size of InAs QWRs is 90 nm while the size along the step lines increasing with the thicknesses of InAs layers, amounting to 1100nm. The height of InAs QWRs varies from 7.9nm to 13nm. Photoluminescence (PL) measurements on the two samples were explored and an obvious PL peak around 967 nm was observed at 25 K. The PL intensity decreases as the temperature increases, and it will vanish above 60 K. However, the QWR sample with thicker InAs layer emits a long emission of 1100 nm -1400 nm as the temperature rises above 50 K, and a longer emission of 1400-1600nm as the temperature approaches to 100 K. We considered that the complex photoluminescence spectra were originated from the multiple energy steps. The carrier migration among the different QWRs structures intensified with temperature, and the chance rate from the higher energy levels to the lower ones which generated a stronger emission of long wavelength. The carrier dynamics of QWR samples were measured by using time resolved PL (TRPL) spectra from 25 K to 100 K. The PL decay time in the QWR structure at longer emission was found to be independent of the temperature as T<100 K, showing a typical dynamical behavior of the localized excitons.
Active Friction Control Based on Electrorheological Effect
Authors: Jiang Ji Le , Tian Yu , Meng Yong Gang
Published: September 2009

A preliminary study of active friction control method based on electrorheological (ER) effect is experimentally investigated. The friction coefficient can be changed from 0.07 to 0.9 continuously with the applied voltage in the range of 0 to 2000 V. Results show that by using proper ER fluids and structure design, active friction control based on ER effect has good potential in real industrial applications.
A New Phosphate-Bonded Investment Material for Rapid Ceramic Molding of Medium-Size Castings
Authors: Li Ting Zhong , Luo Ji Rong , Wu Shu Sen , Wan Li
Published: September 2009

Phosphate-bonded investment（PBI）ceramic mold materials have outstanding properties, such as rapid setting rate , moderate green strength and high temperature strength, and could be widely utilized in dental restoration and micro-casting of artistic products. However, fast hydration and gel rate of the phosphate-bonded ceramic slurry has been an obstacle to the wide applications of ceramic mold material for medium and large-size precision castings. This paper presents a new phosphate-bonded ceramic mold material by modifying the composition of refractory aggregates and additive agents, which is promising to be used for rapid ceramic mold casting for medium-size super alloy components. The results indicate that the properties of ceramic mold slurry including initial setting time and fluidity are suitable for complete embedding medium-scale patterns and get accurate duplicate of external configurations when the amount of boric acid is 1.11wt% and sodium tri-poly phosphate (STP) is 0.92wt%. The strength of ceramic mold material can resist impact force when pouring molten metal and easy take casting out from ceramic mold.
High-Frequency Vibration Response of Metal Honeycomb Sandwich Structure
Authors: He Xiao Dong , Kong Xiang Hao , Shi Li Ping , Li Ming Wei
Published: September 2009

ARMOR TPS panel is above the whole ARMOR TPS, and the metal honeycomb sandwich structure is the surface of the ARMOR TPS panel. So the metal honeycomb sandwich structure plays an important role in the ARMOR TPS, while it bears the flight dynamic pressure and stands against the flight dynamic calefaction. So the active environment of metal honeycomb sandwich structure is very formidable. We have to discuss any extreme situation, for reason of making sure aerial vehicle is safe. And high-frequency vibration is one of active environment. In this paper we have analyzed high-frequency vibration response of metal honeycomb sandwich structure. We processed high-frequency vibration experiment by simulating true aerial environment. Sequentially we operated high-frequency vibration experiment of metal honeycomb sandwich structure with cracks, notches and holes. Then finite-element analysis was performed by way of validating the experiment results. Haynes214 is a good high temperature alloy material of both face sheet and core at present, so we choose it in this paper.
Accurate Displacement Measurement for Landslide Prediction by Sampling Moiré Method
Authors: Morimoto Yoshiharu , Fujigaki Motoharu , Masaya Akihiro , Kondo Hiroyuki , Inuzuka Tatsuya
Published: September 2009

Sampling moiré method is useful to measure shape, displacement and strain distributions of multi-functional materials and structures. When a specimen grating pattern on an object is recorded by a digital camera, a moiré fringe pattern is obtained by sampling the digitized grating image with a constant pixel pitch. The method can analyze phase values from one image of a grating pattern. By using this sampling moiré method, the displacement measurement of land is analyzed to develop a landslide prediction system. The theory and the application for measuring the displacement of land are shown in this paper.
Study on Dynamic Friction Process of Sweat Self-Lubricating Composite at Elevated Temperature Based on CA Method
Authors: Yan Song Shan , Liu Zuo Min
Published: September 2009

In the paper, a three-dimensional model is developed with cellular automaton method based on a series of experiments and the self-lubricating mechanism analysis. The model is used to investigate the dynamic friction process of sweat self-lubricating composite during high temperature sliding. The sliding friction coefficient and the distribution of lubricant on the worn surface of the composite are calculated out by using the cellular automaton (CA) model. The agreement between the computing and experimental results shows the model developed in the paper can be effectively used to study the friction behaviors of the sweat self-lubricating composite at high temperature.
Influences of Pretreatment Solution Concentrations on Copper-Doped SiC Particles Made through Electroless Plating Technique
Authors: Hu Ming , Su Yun Feng , Wu Ming Zhong
Published: September 2009

. Pretreatments for copper-doped SiC particles made by an electroless-plating technique, the preconditions to attain good coatings, were conducted in order to obtain the active and clean surface of SiC particles. An orthogonal experiment method was used to determine the concentration of every pretreatment solution. The morphologies of the coatings were observed in a scanning electronic microscope(SEM), the composition of the coatings was analyzed by an energy-dispersive X-ray analysis (EDS), and the phases in the coatings were identified by a X-ray differtometer (XRD). The influences of pretreatment solution concentrations on the copper coatings quality of SiC particles were dealt with. The results showed that the pretreatment solution concentrations had great influences on the coatings quality of SiC particles. The obvious effects on the copper coatings derived from the coarsening solution concentration. The optimized copper coatings of SiC particles were uniform and dense, no bare SiC particles were seen and the interfaces between SiC and Cu bonded well. The high quality and low cost coatings were also obtained after the expensive PaCl2 activating agent had been substituted for AgNO3.
Formation Enthalpies of 18 Carat Au–Cu–Ni-Zn-RE Alloys Calculated With Chou’ Models
Authors: Xiang Xiong Zhi , Bai Xiao Jun , Ma Song Feng , Zhang Guo Tao , Su Yi Kun
Published: September 2009

A method to estimate the thermodynamic properties of Multi- component white gold alloys from those of constitutive binary alloys was proposed. The Miedema's theory and Chou model. were used to calculate the formation enthalpies of Au–Cu–Ni-Zn-RE alloys. The agreement between the calculation and experiment is reasonable. Formation enthalpies of Au–Cu–Ni-Zn-RE and relative stability of their intermetallic compounds were predicted with present method.
Preparation and Characterization of Nature Rubber/Attapulgite Composites
Authors: Wang Ji Hu , Chen Da Jun , Min Hui Ling , Tang Zhong Feng
Published: September 2009

In this paper, attapulgite(AT)/nature rubber (NR) composites have been prepared through melt blending process. First, different types of attapulgite were prepared.Secend,Fourier infrared spectroscopic (FTIR) was used to analyze attapulgite.Then,different types of attapulgite were filled into natural rubber according to different proportion.Finally, The mechanisms of composites were analyzed. The results showed that siliane coupling agent Si-69 can improve the dispersion of calcined attapulgite and enhance the chemical interfacial adhesion.
Experiment Study on the Chloride Penetration of Steel Fibre Reinforced Concrete
Authors: Bai Min , Niu Di Tao , Wu Xiong
Published: September 2009

In recent years, the concrete material subject to chloride corrosion which impacts greatly on the durability of the building project in the marine or coastal environment has been reported repeatedly. With the problems becoming more and more serious, much attention has been paid on it gradually. To improve the durability of the concrete structure in the marine environment, the author tried to add the different content of steel fiber into the concrete and research the permeability of the concrete in the chloride environment. Four different volumes of steel fiber were selected to prepare the concrete. The dates of the proportion are as follows, 1)0.5%; 2)1%; 3)1.5%; 4)2%. Leave the steel fiber reinforced concrete and plain concrete to soak in the sodium chloride solution which mass percent is 3.5%. The soak time is 30, 60, 90,120, 180 days separately. Among this, the test items include the penetration depth of chloride, the chloride ion content and the splitting strength after soaking period. As a result of the test, it is demonstrated that chloride penetration-resistant of steel fiber reinforced concrete is better than plain concrete. The best performance is obtained when the content of steel fiber is 1.5%. The results will be very useful to the concrete professional dealing with chloride-ion penetration. In conclusion, it is convinced that the application of this result in marine engineering will bring well economic and social environmental benefits for the society.
Interlaminar Shear Strength of Glass Fiber Reinforced Dially Phthalate Laminates Enhanced with Nanoclays
Authors: Kong Zhen Xing , Wang Ji Hui
Published: September 2009

To examine the role of nanoclays in the enhancement of interlaminar shear strength (ILSS) of glass fiber reinforced diallyl phthalate (GFR-DAP) composites, the GFR-DAP laminates were manufactured by hand lay-up techniques using two nanoclays, DK2 and MHAB-MMT, respectively. Χ-ray diffraction (XRD) were conducted to characterize the morphology of the dispersed clay particles in the DAP matrix. The mechanical performances were characterized by flexural strength and LISS measurements. XRD scans shows that the clays disperse uniformly in the DAP matrix and form an intercalated structure with a basal spacing of 3.86 nm and 3.98 nm for DK2 and MHAB-MMT, respectively. Short beam shear tests show that only 2.5 wt% clay loading in DAP matrix increased the ILSS of resulting GFR-DAP laminates by 7.64% and 14.80% for DK2 and MHAB-MMT, respectively, with respect to the neat DAP. The fractured surfaces of resulting laminates were observed by scanning electron microscope (SEM).
Thermal Energy Discharge Characteristics of a PCM Heat Exchanger with Calcium Chloride Hexahydrate
Authors: Zhu Xiao Qin , Hu Jin , Yang Yu Fen , Cao Zhao Sheng , Lu Jian Sheng , Sun Jia Lin
Published: September 2009

Calcium chloride hexahydrate (CaCl2•6H2O) is an important inorganic phase change material used for thermal energy storage or discharge at lower storage temperature. Thermal energy discharge characteristics of a new type of PCM heat exchanger were investigated after thermal energy storage, in which its main body is based on the traditional structure of a shell-and-tube heat exchanger, and is full of PCMs (CaCl2•6H2O) in the tubes. The cold air of 16-17°C with different velocities flowed through the PCM heat exchanger, the temperature distributions of all the test points were measured by means of the experimetal system. The experimental results showed that, since the latent heat of phase transition in the tubes was so large during the process of thermal energy discharge, the time intervals of air temperature that maintained beyond 20°C at the outlet of the PCM heat exchanger were respectively 594min and 717min when the mass velocities of the cold air were 0.132 kg/s and 0.096kg/s, which is one of the important characteristics in the structure of this type of PCM heat exchanger. It can be used in the situations of temperature control or maintenance at the certain temperature, such as greenhouses, air conditioning etc.
Fabrication and Properties of Ce3+ and Tb3+ Co-Doped Ca2SrAl2O6 Phosphor
Authors: Li Xu , Guan Li , Liu Chong , Cong Feng , Yang Zhi Ping
Published: September 2009

In this study, a novel green phosphor Ca2SrAl2O6:Ce3+,Tb3+ were prepared by solid state method. The crystal structure and particle morphology of phosphors were measured by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The result indicated that the phosphor belonged to a single Ca2SrAl2O6 phase and crystalline grain sizes were about 2.0~5.0 μm. The excitation and emission spectra were studied in this paper. Monitored at 545 nm, the excitation spectrum consisted of a broad band at UV region (320-400 nm), which was attributed to the abstract of Ce3+ and Tb3+ ions. Excited by 360 nm UV light, the emission spectrum was composed of four groups narrow band and the emission peaks located at 497, 545, 595 and 623nm, respectively. Luminescent intensity increased with Tb3+ and Ce3+ ions concentration and it would reach the maximum when the activator molar fraction was 0.04 for the highest emission intensity at 545 nm. Concentration quenching would occur if the activator concentration exceeded 0.04 mol-1. Li2CO3 could be used for flux and Li+ ion was used for charge compensation in this experiment. Thus, Ca2SrAl2O6:Ce3+, Tb3+ phosphor was a good candidate of green phosphor for UV based white LED.
Investigation on Microwave Absorbing Properties of Double-Layer Cementitious Composites
Authors: Zhang Xiu Zhi , Sun Wei
Published: September 2009

Double-layer cementitious plates with absorbing microwave properties were designed, based on the impedance matching theory and electromagnetic wave propagation laws. The reflectivity of cementitious composites was measured in the frequency ranges from 8 GHz to 18GHz, and the influence of silica fume on the impedance of the composites surface was studied. Meanwhile, absorbing properties of cementitious plates, which used ferrite and carbon fiber composited ferrite as microwave absorbers, were also investigated respectively. It is shown that the addition of silica fume can improve the impedance matching between the cementitious composites and free space. Compared with the single-layer structure, the reflectivity of the double-layer cementitious plates decreased around 6 dB ~ 8 dB. The maximum reflection loss of double-layer cementitious plate employing carbon fiber and ferrite reached -16.2dB, while the absorption bandwidth under – 10 dB was from 9.6 to 18 GHz.
Damping Performance of Cocured Composite I-Shaped Beams with Embedded Viscoelastic Layers
Authors: Xu Chao , Lin Song
Published: September 2009

Composite I-shaped beams are currently used in aerospace, ocean and civil engineering applications. Increasing the vibration damping of composite structures is a concerned need in those applications. This research is an effort to investigate the damping performance of composite I-shaped beams with cocured viscoelastic damping layers using finite element method and modal testing technique. A hybrid finite element model for a damped composite I-shaped beam was developed. Modal strain energy method was used to estimate the linear viscoelastic modal loss factors of the composite beams. A numerical parametric investigation was conducted to study the effects of various parameters on the dynamic properties of composite beams under free-free end boundary condition. Selective design parameters included inserting location and thickness of damping layers. Natural frequency and modal loss factor were also extracted by experimental modal analysis. Static tests were performed to obtain the loss of static stiffness for inserting soft viscoelastic layers. Experimental and analytical results show the inserting location of cocured damping layers has significant effects on the damping and there exists a critical damping layer thickness for optimal damping with less significant modal frequency decrease. Static tests results demonstrate a little loss of static stiffness for embedding low module damping layers. A careful selection of damping layer location and thickness is needed to optimize the damping benefits desirable and the mechanics stiffness reduction that can be tolerated for intergral damping composite structures.
Anti-Wear and Reduce-Friction Ability of ZrO2/SiO2 Self-Lubricating Composites
Authors: Ma Shi Yu , Zheng Shao Hua , Ding Hai Yang , Li Wei
Published: September 2009

In this paper, the author does research on the surface modified of nanometer ZrO2/SiO2 composite and makes it a good dispersivity in organic solvents. As lubricating oil additive, added it into the base oil with different concentration. Anti-wear and reducing friction performances measured by the four ball test and the thrust-ring tribotester. The results showed that the average friction coefficient decreased 21.14%, the weight lost of the thrust-ring was no wear or negative wear when the additive concentration was 1wt%. The worn surfaces were quite different compared without additive, the grooves formed during the friction experiment become smooth and finally a narrow wear scar. There were many white particles and dimples on gray surface, the white particles were higher than those of gray parts. The white particles was ZrO2/SiO2 composites according to EDS and XRD analysis. The Si and Zr elements appeared on the worn surfaces can not be cleaned out in petroleum ether and ultrasonic ambiance, this is a dynamic self-healing mechanism .
Developing a New Method for the Formation of NiO Hollow Microspheres Using Yeasts as Bio-Templates
Authors: Yang Li , Guan Wie Sheng , Bai Bo , Xiang Yun
Published: September 2009

A novel route for synthesis of biomorphic nickel oxide （NiO） hollow microspheres, using yeasts as bio-templates, has been successfully developed. In the typical process，yeast cells were first coated with nickel hydroxide and then calcinated to obtain nickel oxide hollow microspheres. As-prepared products were characterized by DTA, SEM, XRD and FTIR. A possible formation mechanism of NiO hollow microspheres was proposed in brief.
Study on the Wear Resistance of ZnAl27 Composite Reinforced by SiC Particles
Authors: Xie Jing Pei , Yan Shu Qing , Wang Ai Qin , Wang Wen Yan , Li Gi Wen , Li Xiao Li
Published: September 2009

The microstructures characteristics of interface and wear resistance Of ZnAl27 composite reinforced by SiC particles have been studied by means of SEM and HRTEM. The results shown that SiC particles could be distributed in ZnAl27 alloy uniformly, and the excellent combined interface between SiC particles and ZA27 matrix is formed. CuZn4 could nucleate on SiC particles and grow up at higher speed along SiC particles than at the vertical direction. The wear resistance of the ZnAl27 alloy could be increased remarkably due to the addition of SiC particles. When the SiC particles are added to 30％, the wear resistance was raised by 126.5 times
Effects of Chlorine Ion on the Photocatalytic Activity of Cuprous Oxide Powders Prepared by Hydrothermal Method
Authors: Zhai Ji Wei , Gao Rong Jie , Jiang Kui Guang , Sun Ming Zhi
Published: September 2009

Cuprous oxide(Cu2O) microcrystals were successfully synthesized via hydrothermal method using CuSO4•5H2O and Na2SO3 in HAc-NaAc buffer solution. The products were characterized by X-rays diffraction (XRD) ,scan election microscopy (SEM) and ultraviolet-visible (UV-vis) spectroscopy. The photocatalytic activity of the as-prepared Cu2O powders was evaluated by the photocatalytic degradation of methyl orange solution under visible light irradiation at room temperature in air. The effects of chlorine ion on the photocatalytic activity of the Cu2O powders were investigated and discussed. The results show that chlorine ion in solution can obviously decrease the photocatalytic activity of Cu2O. When the concentration of chlorine ion increased to 0.5mol/L(about Cl- concentration in the seawater), the photocatalytic ratio of Cu2O decrease to 45% compared with the value in pure water. Increasing solution pH can enhance the photocatalytic activity of Cu2O. The mechanism of photo-degradation was discussed.
Synthesis of NH2-Functionalized Nano-Fe3O4 Magnetic Polymer Adsorbent and its Application for the Removal of Cr (VI) from Industrial Wastewater
Authors: Zhao Yong Gang , Shen Hao Yu , Hu Mei Qin , Wei Feng , Luo Yun Jie , Xia Qing Hua
Published: September 2009

In this study, a novel NH2-functionalized nano-sized magnetic polymer (TEPA-NMP) adsorbent coupling with tetraethylenepentamine (TEPA) had been prepared. Its application for the removal of Cr(VI) from industrial wastewater was investigated. Batch adsorption studies were carried out to evaluate the effects of pH value, initial concentration, adsorption isotherm, adsorption kinetics, and desorption characters etc. The adsorption of Cr(VI) reached equilibrium rapidly within 30 mins. The adsorption efficiency of the TEPA-NMP on Cr(VI) was dependent on pH value and the initial Cr(VI) concentration. The adsorption efficiency of Cr(VI) decreased with the increasing of the initial Cr(VI) concentration and pH value. The adsorption data were well fitted with the Langmuir isotherm. The maximum adsorption capacity calculated from the Langmuir isotherm was 370.4 mg/g at temperature of 35 °C and pH of 2.0. Regeneration studies indicated that the adsorbent could be reused for 8 times with only 3.4 % lost of adsorption efficiency. The adsorption mechanism study results suggested that the adsorption of Cr(VI) could be related with electrostatic attraction, ion exchange and coordination interactions.
A Study of Surface Treatment on LY12 Aluminum Alloy by γ-APS
Authors: Xia Dong Sheng , Gao Yu Zhou , Zhang Hui Chen , Yu Yan
Published: September 2009

The work aims to investigate the anti-corrosion behavior of silane treated LY12 aluminum alloy (AA LY12) and optimize the process conditions of silane treatment. The silane films were prepared on AA LY12 from γ-aminopropyltriethoxysilane (γ-APS) hydrolized in ethanol/water mixture by dip coating method. The optimum process parameters were obtained from the orthogonal designs in terms of silane solution concentration, ethanol/water ratio, dipping time, curing temperature and curing time. Prior and after silane treatment, the surface of AA LY12 was characterized by contact angle measurements and scan electron microscopy (SEM). The potentiodynamic polarization tests and electrochemical impedance spectroscopy measurements (EIS) were employed to study the anti-corrosion characteristics of silane films on AA LY12. The impedance plots were fitted with the different equivalent circuits. Furthermore, the influence of the above process parameters of silane treatment on film formation and anti-corrosion performance was explored. The results indicate that the γ-APS treated AA LY12 significantly improved the corrosion resistance, compared to the untreated one.
Self-Hardening Calcium Phosphate Composite Scaffold for Bone Tissue Engineering
Authors: Liu Hua , Zhou Chang Ren
Published: September 2009

Calcium phosphate cement (CPC) sets in situ to form solid hydroxyapatite, can conform to complex cavity shapes without machining, has excellent osteoinductivity, and is able to be resorbed and replaced by new bone. Therefore, CPC is promising for craniofacial and orthopaedic repairs. However, its low strength and lack of macroporosity limit its use. This study investigated CPC reinforcement with absorbable fibers, the effects of fiber volume fraction on mechanical properties and macroporosity, and the biocompatibility of CPC-fiber composite. The liquid phase of CPC in this study was the weak acidic solution of chitosan. Chitosan has favourable biocompatibility, which has high viscosity in solution. The incorporation of chitosan could improve the handling properties of CPC. The liquid phase contained citric acid could strongly improve the hydration rate of CPC, which shortened the setting time and increased the compressive strength of CPC. In addition, the weak acidic environment around the biomaterials could accelerate the degradation of CPC, which was important to bone tissue engineering. The rationale was that large-diameter absorbable fibers would initially strengthen the CPC graft, then dissolve to form long cylindrical macropores for colonization by osteoblasts. Compressive strength was measured vs. fiber volume fraction from 0% (CPC Control without fibers) to 70%. Animal experiment showed that the material had osteoinductivity and biodegradability when the material was implanted into the muscle pouches in the thigh of rabbits. Compressive strength (mean ± SD; n=3) of CPC with 70% fibers was 0.8± 0.1 MPa. Long cylindrical macropores 100~300 μm in diameter were created in CPC after fiber dissolution, and the CPC-fiber scaffold reached a total porosity of 75.1±1.2% with 70% fibers. The new CPC-fiber formulation had good potentiality of ectopic bone induction. The method of using large-diameter absorbable fibers in bone graft for mechanical properties and formation of long cylindrical macropores for bone ingrowth may be applicable to other tissue engineering materials.
Melt Temperature Dependence on Glass Forming Ability of Al-Mg Alloys
Authors: Geng Hao Ran , Deng Yan Bo , Wang Zhi Ming , Wang Xue Liang , Li Zhen Yuan
Published: September 2009

The relationship between the viscosity of Al84Mg10Ce6 alloy melt and liquid structure was studied by viscosity measurements, X-ray diffraction and DSC analysis in this paper. In addition, the glass forming ability of alloy ties produced by melt spinning was analyzed. Based on the above results, the relationship between alloy melts and its glass forming ability(GFA)was studied. The addition of element Ce leads to the abnormal change of Al84Mg10Ce6 melt’ s structure and enhances its GFA, furthermore, it results in completely amorphous ties with melt spinning at 850°C.Therefore, there is certain relationship between the Al-Mg based alloys melt and its GFA.
Study on Seawater Corrosion of Fe-Al Intermetallic Compound
Authors: Bai Qing Hua , Wang Xin , Fan Wen Tao
Published: September 2009

The corrosion behavior of Fe3Al intermetallic compounds annealed at various temperatures in sea water was studied. The results indicated that both structure ordering and surface oxidation film can significantly improve the anti-corrosion performance of Fe3Al alloys. Furthermore, there was no significant difference in anti-corrosion performance between Fe3Al samples of DO3 and B2 structure. The corrosion mechanism of Fe3Al alloys in seawater was probably as follows: Al element is preferentially corroded, Fe corrosion followed when Al element has been corroded away from the sample surface as well as the reduce ratio of Al becomes smaller than the dissolution ratio of Fe.
The Uniform Elongation of Web and Flange of H-Beam
Authors: Ma Jin Hong , Zhang Wen Zhi , Chen Wei , Zheng Shen Bai , Li Hong Bin
Published: September 2009

H-beam is widely used in the construction in virtue of its excellent sectional properties. Because of its complex section, flange and web are deformed in different zones in rolling process. The traditional elongation ratio between flange and web is 1.03~1.05, which obtained from experience. Web wave, crack, or flange crack, and the large residual stress exist in the H-beam production. The problems are mainly caused by the uneven elongation of flange and web. It is necessary to keep uniform elongation of flange and web to solve these problems. The modified reduction ratio between flange and web is provided in this paper. The ratios improve the quality of H-beam by simulation and experiment.
Damage Evolution of Delayed Fracture in Woven GFRP under Hot Water Environment
Authors: Kotani Masahiro , Nakamichi Koutarou , Yasufuku Yusuke , Kawada Hiroyuki
Published: September 2009

Present paper deals with the delayed fracture in woven GFRP underwater at elevated temperature. The tensile test of GFRP after water immersion was conducted to evaluate the residual strength ater immersion at various water temperatures. The residual strength of GFRP decreased with the increase in the water temperature and the immersion time. In fact, the transition in failure mode with water immersion was ascertained from SEM observation of the fracture surface. Additionally, creep test in air and under hot water at 95°C was conducted. The creep rupture time decreased drastically with water immersion, in contrast, creep rupture wasn’t observed from the creep test in air. It was clarified that the water immersion generated the transition in the failure mode of GFRP and therefore led to the acceleration of the strength degradation.
Oriented Growth of cBN Crystals Along [100] Direction in Hydrothermal Conditions
Authors: Lian Gang , Zhang Xiao , Zhu Ling Ling , Tan Miao , Cui De Liang , Wang Qi Long
Published: September 2009

Controlling the shape of cBN has been met with limited success. This work mainly reports a hydrothermal route to synthesize cBN nanocubes with oriented growth along [100] direction. XRD, TEM and SEM are applied to characterize the structure properties. Regular cubes of cBN have perfect quality and good uniformity. The square symmetry illuminates that cBN cube is a single crystal bounded mainly by the less stable {100} facets. This special morphology is determined by the ratio(R) between the growth rates along [100] and [111] direction.
Through-Thickness Texture Variation in Non-Oriented Electrical Steel Sheet Produced by Asymmetric Rolling
Authors: Pei Wei , Sha Y.H. , Yang H.P. , Zhang F. , Zuo Liang
Published: September 2009

The hot bands of non-oriented electrical steel were cold rolled by asymmetric rolling with speed ratio of 1.125 as well as conventional symmetric cold rolling to investigate the effects of cold rolling mode on through-thickness texture variation. Asymmetric rolling shows a marked weakening effect on α fiber (RD//<110>) running from {001}<110> to {112}<110> through sheet thickness, especially at the side contacting with faster roll. Asymmetric rolling increases {111}<112> component while decreases {111}<110> component through sheet thickness except for the surface layers. The through-thickness texture variation due to asymmetric rolling was explained in terms of shear strain distribution.
The Concentration Fluctuation near Critical Temperature of Liquid Bi33.3Ga66.7 Alloy
Authors: Wang Zhi Ming , Geng Hao Ran , Zhou Guo Rong , Guo Zhong Quan , Teng Xin Ying
Published: September 2009

The temperature dependence of resistivity of liquid Bi33.3Ga66.7 and Bi12Ga88 alloys was measured. Anomalous negative deviation of electrical resistivity of liquid alloys was found near critical temperature. Analysis in terms of the calculating equation for resistivity of liquid alloy suggests that, besides SCC(0), the pseudopotential matrix element and alloy composition still serve as crucial factors in scattering function. That is, concentration-concentration fluctuation in the long-wavelength is not necessarily induced an increase of resistivity of liquid alloy near critical temperature.
Strength Prediction of Connecting Frame in Aircraft Composite Cabin
Authors: Zhao Li Bin , Liu Feng Rui , Zhang Jian Yu
Published: September 2009

The mechanics behavior of connecting frame in aircraft composite cabin under static load is researched by three-dimensional finite element analysis. After obtaining the stress distribution, a progressive damage method is adopted to predict the structure strength of the connecting frame. The stiffness and strength are simulated. Furthermore, the damage onset and failure mode are described. The numerical results illustrate the analysis provides insight into the structural strength and distribution of stress and highlights areas requiring further structural design.
Corrosion Properties of Magnetron Sputtered Al-Mg Alloy Coatings on High-Speed Electro-Galvanizing Steel
Authors: Gu Xun Lei , Shan Yu Qiao , Liu Chang Sheng
Published: September 2009

The Al-Mg coatings were deposited on high-speed electro-galvanizing steel by using double-target DC magnetron sputtering. Numerous Al-Mg coatings were prepared with a range of different Mg-target power at different substrate temperatures. The morphologies and compositions were analyzed by SEM, EDS and XRD, the corrosion-resistance properties with different sputtering parameters were discussed by electrochemical measurement. It was found that with the substrate temperature increasing, the porosity decreased, meanwhile, higher substrate temperature resulted in more granular particles and an increased average particle size, but that did not affect corrosion properties obviously. The corrosion-resistance properties were found to be significantly affected by the targets power. As the power of Al-target and Mg-target were 900W and 200W respectively, the film acted the best corrosion-resistance property. Corrosion current density was approximately 4μA/cm2, decreased significantly compared with galvanized sheet. After analysis, the coating was mainly composed of Al12Mg17 which afforded sacrificial anode protection. As the Mg-target power over high relative to Al-target, the coating was composed of Al12Mg17 and MgZn2, the latter can cause micro-galvanic acceleration of corrosion.
Microstructures of the Fiber-Round Hole of the Chafer Cuticle
Authors: Wu Xin Yan , Guan Fu Ling , Chen Bin , Wang You Wei
Published: September 2009

In this paper, microstructure and mechanical properties of the chafer cuticle were investigated. The microstructures of the chafer cuticle were first observed with a SEM. It showed that the cuticle is a kind of chitin-fiber-reinforced biocomposite with protein matrix. There are some holes existing in the chafer cuticle and the fibers around hole are continuous. Based on the observed results of the SEM, the analyses of 3D models on the simple composite elements with fiber-round hole were conducted. The result showed the microstructures of composite laminates with fiber-round holes can decrease the stress concentration and well transfer the stress. So it can improve the strength and toughness of the composite laminates included holes. These conclusions may present a bio-inspired approach for design and development of advanced man-made fiber-reinforced composites.
Thickness Measurement of Composite Material Using Eddy Current Testing
Authors: Chen Pei Hua , Huang Ping Jie , Ye Bo , Li Guo Hou , Zhou Ze Kui
Published: September 2009

Composite materials have some obvious advantages such as high specific strength 、high specific modulus 、corrosion resistant 、abrasion resistant and so on, it is believed to be highly competitive compare to other materials. Advanced composite materials have been used more and more widely in defense industry, among them carbon fiber reinforced resin base composite material is most representative [1] ,there has great value for the study of carbon fiber composite materials. Eddy current is a nondestructive testing technology widely used on metal materials, the using of eddy current technology in aviation domain has a long history, but there is few reports on composite material with eddy current NDT. Experiments show that eddy current used on composite material is feasible, and the result is satisfactory. The thickness measurements of carbon fiber advanced composite materials have been done in two different ways.
Preparation of pH Sensitive Polyacrylic Acid(PAAc) Macroporous Hydrogels in Aqueous NaCl Solutions and their Characterization
Authors: Xue Yu Hua , Zhao Wen Yuan , Sun Shou Feng , Yu Hu
Published: September 2009

In this study, macroporous, pH sensitive polyacrylic acid hydrogels were prepared by using different concentration of aqueous NaCl solutions as the polymerization medium. The optical photos showed that the pore morphologies of the hydrogels were dependent on the concentration of NaCl. Swelling studies showed an increase in equilibrium swelling ratio as the NaCl concentration in the polymerization medium increased from 0 to 0.7mol/L. The hydrogels exhibited stronger sensitivity to pH changes, and showed much faster reswelling and deswelling response rates with the NaCl concentration increasing in the polymerization medium.
Effects of Electric Pulse Modification with Different Technique Parameters on the Liquid Structure of Pure Aluminum
Authors: Qi Jin Gang , Wang Jian Zhong , Wang Bing , He Li Jia , Du Hui Ling
Published: September 2009

The modification of liquid metal by electric pulse (EP, EPM) is a novel method for grain refinement. In this study, based on the reported structural heredity of EP-modified liquid aluminium, the structure tests of EP-modified liquid aluminium with different technique parameters were conducted by using high temperature X-ray diffractometer. The results show that the quantitative structure changes of EP-modified liquid aluminium have a close relationship with the modifying time and modifying temperature. The decrease of modifying time could result in an obvious weaker principal peak in structure factor curve compared with the optimal EP technique parameters, but a slight increase of coordination number (Ns), correlation radius (rc) and average atom number per cluster (Nat) is still observed under this condition. These facts indicate that the EP-modified liquid aluminum could gain an increasing order degree, and thus have an advantage during the formation of a stable nucleus, eventually leading to a grain-refining solidification structure. On the other hand, the structure factor curve of EP-modified liquid aluminum at the high modifying temperature of 850°C tends to be overlapped with that of the unmodified during the principal peak range. In this case, the competition result between the EP strengthening effect and the destruction of superheating would determine the final structure of EP-modified liquid aluminum.
Detection and Characterization of Fatigue Induced Damage Using Electromechanical Impedance Technique
Authors: Soh Chee Kiong , Lim Yee Yan
Published: September 2009

In this paper, the feasibility of damage detection and characterization using the EMI technique on high cycles fatigue induced damage is investigated. Cyclic tensile load is applied on a lab sized aluminium beam up to failure. Piezo-impedance transducer in the form of PZT patch (lead zirconate titanate) is surface bonded on the specimen for crack detection. Progressive shift in admittance signatures measured by the PZT patch corresponding to increase of loading cycles reflects effectiveness of the EMI technique in tracing the process of fatigue damage progression.
Electrical Response and Mechanical Behavior of Plasticized PVC Actuators
Authors: Xia Hong , Ueki Takamitsu , Hirai Toshihiro
Published: September 2009

By changing gel and electrode shape, many different actuators could be invented. In the previous papers, we have reported that Maxwell stress generated in the PVC gels was expected as the results of polarization response of charges, and it mainly took place between the gel and the anode due to the accumulated negative charges on surface of the PVC gel near anode. Due to the existence of the Maxwell force, the PVC gel will be deformed asymmetrically and resulted in creep deformation along the anode. In this paper, we conducted some mechanical experiments and investigated the modulus of PVC gels with varied contents of plasticizer DBA. It was found that PVC gels were separated to two layers obviously after applied an electrical field. Near the anode, the layer (L1) was thinner and softer than other layer (L2) due to the transfer of plasticizer to the anode. This phenomenon was also confirmed by a fluorescence microscope. The displacement of gel in both sides near electrodes was different, and then a bending force was generated due to the force of electrical field. On the other hand, the recovery time of the deformed gel depended on the contents of plasticizer. The longer recovery time was observed for the lower content of plasticizer. The Young’s modulus of PVC gels in tensile becomes small after applied an electrical field and the gels became to be deformed easily.
Influence of Aggregate Gradation on Mechanics Performance of Strain-Hardening Cement-Based Composites (SHCC)
Authors: Tian Li , Chen Jing Ru , Zhao Tie Jun , Ding Zhu
Published: September 2009

The high brittleness of cement-based materials is the dominant reason that causes cracking, corrosion, and even losing the load bearing capacity of the structure. PVA fiber reinforced Strain-hardening Cement-based Materials (SHCC) which is characterized by strain-hardening and multi-micro cracking significantly improves the mechanics performance of cement-based materials. In this paper, 3-point-bending and direct tensile tests were conducted to contrast influence of the material mechanics on SHCC by aggregate gradation. Tests results demonstrate that appropriate particle gradation may improve the strain hardening section in the stress-strain curve. Therefore, the maximum diameter of aggregate can be enlarged from 110μm to 1.25mm. Comparatively large aggregate will be convenient for such materials in the practical application and popularization.
N-(n-butyl)-3-aminopropyltrimethoxysilane-Functional Modified Pyrophyllite: Preparation, Characterisation and Pb(II) Ion Adsorption Property
Authors: Liu Hai Tao , Zhou Yong Qiang , Sheng Zhen Hong , Wu Chun Lian , Zhang Jing Feng , Lin Shie , Weng Xue Jun
Published: September 2009

The pyrophyllite used in this study was from Taishun County(Wenzhou,China). The surface of pyrophyllite was modified by coating with N-(n-butyl)-3-aminopropyltrimethoxysilane (BAPTS) coupling agent and utility of the BAPTS-modified pyrophyllite was investigated as an adsorbent for removal of Pb(II) ions from aqueous solutions. XRD and SEM analysis were used to characterise the surface modification. It can be clearly observed that the pyrophyllite looses its aculeated surface structure and gains more smooth morphology. It was observed that the BAPTS -modified pyrophyllite adsorbed approximately 94.50% of Pb(II) ions at an initial concentration of 10 mg/l and an amount of BAPTS of 2.0%.
Properties of Multiple-Functional Cationic Silk Fabrics
Authors: Xiang Wei , Cai Zai Sheng
Published: September 2009

The silk fabric was chemically modified with 3-(trimethoxysilyl) propyl dodecyl dimethyl ammonium chloride (HSQA), a cationic modifying agent, to promote antibacterial property against S. aureus and E. coli. The dyeing and colorfastness properties of modified fabrics with commercial synthetic dyes, that is, acid and reactive dyes were also improved. The modified silk fabrics also exhibited some improved resiliency. Therefore, the wear properties of fabrics were expected to be improved by the technique of modification. However, the modification caused a slight decrease in the tensile strength of silk fabrics, as well as the whiteness and wettability because of introducing hydrophobic siloxane chains into amorphous regions of silk fibroin. The surface structure of modified silk fiber was studied by X-ray photoelectron spectra (XPS) and FT-IR spectra.
Key words: Silk fabric; multiple-function; Wear property; antibacterial property; X-ray photoelectron spectrum; FT-IR spectrum
Catalyst Assisted Synthesis of Carbon Nanotubes Using the V-Shaped Pyrolysis Flame Method
Authors: Liu Yuan Chao , Sun Bao Min , Ding Zhao Yong
Published: September 2009

Flames offer potential for synthesis of carbon nanotubes(CNTs) in large quantities at considerably lower costs than that of other methods currently available. Synthesis CNTs from V-shaped pyrolysis flame is a kind of novel technique. This study aims to examine conditions for CNTs formation in V-shaped pyrolysis flame. Synthesis inner the V-shaped body and providing heat outer is distinct characteristic in the method. A premixed carbon monoxide/hydrogen gas diluted by helium gas flow was introduced into V-shaped body bottom centre. Simultaneously, as catalyst precursor, pentacarbonyl iron was entrained after ultrasonic atomization into the central pipe by helium gas flow. The rich acetylene/air premixed gas, providing heat source, was introduced into V-shaped body outside surface. Scanning electron microscopy and transmission electron microscopy images of the carbon products were examined. Large quantities of CNTs with the less carbon impurities were formed in the process. Carbon nanotubes can grow well when the sampling time was 5 minutes.A nanotube formation ‘window’ is evident with formation limited to fuel equivalence ratios between 1.6 and 1.8. Furthermore, temperature range was from 850°C to 950°C.Nanoparticles associated with nanotube bundles were identified as primarily ferric oxide.