bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Structures and Properties of CaSO4 Whiskers/PVC Composites
Authors: Zhang Shu Hua , Gan Wen Jun , Sun Wu Xing , Ling Chen Jun , Wang Xie , Li Qing Feng
Published: September 2011

Structures of CaSO4 whisker(A) and CaSO4 whisker(B) were characterized by IR and XRD, and the morphologies were observed by optical microscope. The results showed that the modified CaSO4 whisker(B) has perfect crystal structure, high crystallinity and less defects. Mechanical properties and static thermal stability time(190 °C) of two composites which were prepared by CaSO4 whisker(A) / PVC and CaSO4 whisker(B) / PVC were tested separately, and the degradation processes were analyzed by TG at 50 °C-400°C, N2 atmosphere, and the dispersing states of two whiskers in the composites were observed by means of optical microscope and SEM. The research results showed that the tensile strength and elongation at break increased over 3 MPa and 40% separately, and the static thermal stability time was over 90 min of CaSO4 whisker(B) / PVC, the initial degradation time was delayed comparing with CaCO3 / PVC composite. The consistency and interfacial configuration between whisker and PVC resin were perfect, and the toughness and thermal stability of the composite was improved after CaSO4 whisker was modified. The research results indicated that modified CaSO4 whisker has better toughness and thermal stability actions for PVC.
Preparation of Carbon-Encapsulated Alloy Nanomaterials by Detonation Decomposition of Nitrate Complex Explosives Containing Multi-Metallic Ions
Authors: Li Xiao Jie , Luo Ning , Liu Kai Xin
Published: September 2011

Carbon-encapsulated iron-based alloy nanoparticles with a core-shell structure were prepared by detonation decomposition of nitrate complex explosives containing multi-metallic ions. The size and magnetic properties of the as-prepared composite particles were revealed by X-ray powder diffraction, transmission electron microscopy, energy dispersive X-ray detector and magnetic measurements. Results showed that the different sizes of the ferronickel and ferrocobalt nanocrystal core and the thickness of the carbon shell could be yielded by adjusting the component materials of the explosives. The composite particles had a gamma- or alpha- ferronickel or bcc-ferrocobalt nanocrystal core with a coating of graphitic carbon layers. Magnetic measurements indicated these composite nanoparticles were superparamagnetism at the room temperature, with some variation in the values of saturation magnetization, remanences and coercive forces.
Effect of Ceramic Powder Size on Microstructure and Mechanical Properties of Ti(C, N)-Based Cermets
Authors: Zhan Bin , Liu Ning , Xu Wei , Shi Jin Gang
Published: September 2011

Four Ti(C, N)-based cermets was fabricated from different size of ceramic powder by the conventional powder metallurgy technique. Microstructure, fracture surfaces and crack propagation path of samples were observed by SEM, and mechanical properties such as transverse rupture strength, hardness and fracture toughness were measured. Results show that with the refinement of the raw TiC/TiN powders, the black cores and ceramic grains tend to be finer, the gains with white core-grey rim structure obviously increase, and the microstructure of cermet becomes inhomogeneous. The cermets fabricated from fine powders possess higher porosities. Compared with the cermets made from micron ceramic powders, the cermets fabricated from ceramic powders containing nano powder possess higher transverse rupture strength and lower fracture toughness. When the cermet is fabricated from micron TiC/nano TiN powders, its combination property is the best.
Evaluation Methods for the Dynamic Humidity Control Performance of Humidity-Controlled Composite Materials in Greenhouse
Authors: Wei Feng Lan , Chen Wei , Liu E , Zhang Cai Bei
Published: September 2011

According to internal heat and moisture transfer coupling equations for the humidity-controlled composite materials in greenhouse, the analytical solutions are obtained under the steady periodic conditions, then the moisture desorption and adsorption properties of humidity-controlled composite materials in a closed space are investigated. It shows that the air humidity ratio in the closed space changes periodically in consistent with the air temperature. The ratio of the absolute humidity amplitude to the air temperature amplitude is a constant, which can be taken as a criterion to evaluate the humidity control performance of the material. A simple method, the close box and heat impulse method is put forward to measure the constant value. It can directly embody humidity-controlled traits of materials under the condition of periodic heat and moisture.
The Effect of Carbon Substrates on In Situ Synthesis Carbon Nanotube and Carbon Nanospheres by CVD Process
Authors: Sun Zhen Feng , Qi Le Hua , Gong Qiao Juan , Shu Yang
Published: September 2011

The morphology and growth mechanism of carbon nanotubes(CNTs) and carbon nanospheres (CNSs) produced by in-situ CVD method on different substrates were investigated using scanning electron microscopy (SEM), transmission electron microscope (TEM) and energy dispersive spectrometer (EDS) technology. The experimental results show that the growth of carbon-nano-material has great substrate independence during in-situ CVD process. At the same reaction conditions, CNTs with diameters of 60-140nm and CNSs with diameters of 150-450nm were synthesized on the 1K carbon cloth and graphite paper substrate, respectively. Based on the experimental results, a probable growth mechanism was presented for different carbon substrates. The explanation for the formation process is the difference of the concentration gradient and growth rate in the catalyst.
Effect of 11S/7S Ratios on Mechanical and Barrier Properties of Edible Films Based on Soybean Protein Isolate
Authors: Zhao Xiao Yan , Guo Kuan , Zhang Chao , Ma Yue , Li Xi Hong
Published: September 2011

The effect of 11S/7S ratios on mechanical and barrier properties of soybean-protein-isolate films was evaluated. The tensile strength increased with an increase of 11S globulin ratio when it was higher than 50 % in soybean-protein-isolate films, and decreased with an increase of 11S globulin ratio when it was lower than 50%. Moreover, the total soluble matter of soybean-protein-isolate films decreased with an increase of 11S globulin ratio, while the elongation at break, moisture content, and optical transparency of soybean-protein-isolate films increased with an increase of 11S globulin ratio. Furthermore, 11S/7S ratios had no influence on the water vapor permeability of soybean-protein-isolate films. These phenomenon mainly resulted from that the matrix of soybean-protein-isolate films was mainly maintained by disulfide bonds when 11S globulin ratio was higher than 50%, while that was maintained by intermolecular hydrogen bonds when 11S globulin ratio was lower than 50%.
Elastic Constants and Thermodynamic Properties of Cu, Cu2O and CuO from First-Principles Calculations
Authors: Liu Na Na , Sun Jian Lin , Wu Di
Published: September 2011

Elastic constants and some thermodynamic properties of Cu and copper oxides were studied by first-principles total energy calculations. The elastic constants of Cu and copper oxides were calculated on pressure. It was shown that the calculated elastic constants of Cu, Cu2O and CuO at zero pressure were well consistent with previous experimental data. The specific heat capacities and thermal expansion coefficient of Cu and copper oxides were successfully obtained. The calculated specific heat capacities of Cu were well consistent with the previous experimental data.
Finite Element Analysis of Centrally-Debonded Composite Sandwich Beam under Four Point Bending
Authors: Yeh Meng Kao , Chiu Yu Wen
Published: September 2011

Sandwich structure, with high specific strength, high specific stiffness facesheet and light-weighted core material bonded together, is one of commonly used composite structures. During the manufacturing process, it is possible to have debonding between facesheet and core. This facesheet/core debonding affects the mechanical property and strength of sandwich structure. In this study, sandwich beams are made of graphite/epoxy laminate as facesheet and MWNTs/epoxy nanocomposites as core material. The composite sandwich beam, with a central facesheet/core debond and under four point bending, was analyzed by the finite element method. The length of the debonding layer, the fiber orientation of the facesheet laminate and MWNTs content in core were varied to assess their effects on the bending behavior and the strengths of the centrally-debonded sandwich beams.
Synthesis and Characterization of Nickel-Based Monolithic Aerogel via Sol-Gel Method
Authors: Bi Yu Tie , Ren Hong Bo , Chen Bo Wei , Zhang Lin
Published: September 2011

The synthesis and characterization of nickel-based aerogel prepared using nickel chloride as the precursor via sol-gel method is described. The addition of the polyacrylic acid as an template to the solution of NiCl2•6H2O can guide the gelation in the reaction to build a three dimensional open structure. The aerogel has been characterized using field emission scanning electron microscopy (FESEM), highresolution transmission electron microscopy (HRTEM), nitrogen adsorption desorption analysis and powder X-ray diffraction (XRD). The results indicate that the nickel-based aerogel has a typical three dimensional structure made up of spherical particles with an open porous network and has high surface area about 192 m2/g, average pore diameter about 40nm. The X-ray diffraction (XRD) patterns show that the aerogel prepared at room temperature belongs to amorphous material. The synthesis of nickel-based aerogel, using polyacrylic acid as an template, is especially unique in our experiment.
Microstructures and Mechanical Properties of Cast Aluminum Bronze Enhanced by Modified Nano-SiC Powders
Authors: Yang Jun , Chen Mei Ling , Gao Hong
Published: September 2011

The microstructures and mechenical properties were studied of the reinforced cast aluminum bronze by modified nano-SiC powders have been invastigated in this paper. The results show that the structures and fractograph of the samples are obviously refined, and the β phase was obviously reduced, while the strength and toughness are significantly increased by 14% and 51% simultaneously.
A Study on Mathematical Modeling Technology for Magnetic-Fluid Grinding
Authors: Wu Shu Qin , Li Yao Ming
Published: September 2011

The paper introduces the precision processing technology of grinding using magnetic fluid and presents the working mechanism of magnetic-fluid grinding. Based on Preston Equation, it also establishes a mathematical modeling for magnetic-fluid grinding, which is used to study the relationships between the effects of grinding and the variation of such technological parameters as the revolving speed of work-piece, the intensity of magnetic field, the distance between work-piece surface and magnetic center, the size of the magnetic fluid and grinding time, etc. Analysis on the grinding of Si3N4 ceramic-balls proves that the model has been well established.
Study of Oxidation and Passivation Behavior of Fe Noparticles
Authors: Wang Min
Published: September 2011

Fe nanoparticles prepared by the arc was used in the present study. It was oxidized by laying in the air and passivated by argon ion bombardment. The microsturcture, oxygen content and oxygen atom position in oxidized Fe nanoparticles were investigated. Furthermore, the variation of oxygen content with time in the passivated Fe nanoparticles and Fe nonparticles was also studied. The results showed that the effective size of oxidized Fe nanoparticles was about 10nm-40nm, and oxidation process was conducted on the surface. On the other hand, the oxygen content in passivated Fe nanoparticles reduced by comparing with that laying in the air for the same time.
Formulation of Vanillin Cross-Linked Chitosan Nanoparticles and its Characterization
Authors: Wang Guang , Li Pu Wang , Peng Zheng , Huang Mao Fang , Kong Ling Xue
Published: September 2011

Chitosan nanoparticles were successfully prepared by chemical cross-linking with vanillin. The nanoparticles were spherical in shape with smooth surface, and the average particle size of chitosan nanoparticles was 141 nm. The formulation of chitosan nanoparticles is based on Shiff reaction between aldehyde group of vanillin and amino group of chitosan. Chitosan nanoparticles prepared by crosslinking with vanillin are promising vehicle for the drug delivery of various anticancer drugs in the chemotherapy of cancers.
Finite Element Analysis of the Effect of Blank Holder Force on Deep Drawing of Bottom of Vacuum Flask
Authors: Zhou Liu Ru , Hu Xian Wen
Published: September 2011

Numerical simulation of deep drawing of bottom of vacuum flask is made by means of finite element software ANSYS/LS-DYNA and the potential defect was analyzed. The influence of the blank holder force on deep drawing quality is discussed .The results show that the maximal value of stress and thickness appears in the round corners of die .The maximal increased thickness is sheet flange and the maximal thinning is the round corners of punch. The larger is the blank holder force, the less equal is the thickness and the poorer deep drawing quality.
Graphene-Poly(Methyl Methacrylate) Composites Prepared by Two Methods
Authors: Lei Lin , Qiu Jian Hui , Wu Xue Li , Zhao Yang , Sakai Eiichi
Published: September 2011

Graphene-poly(methyl methacrylate) (GNS-PMMA) composites were prepared by two methods. Graphite oxide nanosheet-poly(methyl methacrylate) (GO-PMMA) composites were prepared of methyl methacrylate monomer and the presence of graphite oxide (GO). Then the GO-PMMA composites were reduced to graphene nanosheet-poly(methyl methacrylate) by using hydrazine hydrate. The obtained composites were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The composite exhibited conductivities in the 1.58×10-9-4.21 S/cm range, depending on the amounts of graphite oxide and PMMA.
Study on Antibacterial Efficacy and Catalytic Capability of Nanocrystalline Magnesia
Authors: You Xiu Dong , Zhu Meng Fu , Su Hong Bo , Chen Ping , Deng Cheng
Published: September 2011

Abstract: Objective: To study the antibacterial efficacy and the catalytic capability of nanocrystalline magnesia powder(nano-MgO). Methods: The antibacterial efficacy was evaluated in Bacteriostatic circle and the shake flask test and the catalytic capability was evaluated by paraoxon. Results: The nano-MgO had good antibacterial efficacy and highly catalytic capability. The catalytic capability was not influenced by light. When 50mL 20μg/L paraoxon solution was catalyzed by 0.5g nano-MgO for 5min, the disappearance of paraoxon was about 77.9%, and for 60min, the disappearances of them was 99.6％. Conclusion：The nano-MgO had good antibacterial efficacy and highly catalytic capability. Key words: nanocrystalline magnesia , antibacterial efficacy, paraoxon, catalytic degradation
Investigation on Dislocations in C-Plane Electron-Irradiated GaN Epilayers by Wet Chemical Etching
Authors: Tian Yuan , Liang Li Min , Wu Wen Cheng , Hao Qiu Yan , Liu Cai Chi
Published: September 2011

The dislocations in electron-irradiated c-plane n-GaN epitaxial layers grown on c-plane sapphire substrates by MOCVD were revealed by several different wet chemical etching methods. And the defect-selective etching method combined with SEM was carried out to study the mechanism of dislocations generation of GaN. SEM images of GaN epilayers with several individual methods are in good agreement with each other. Among all the defects, threading dislocations (TDs) dominated in the GaN epilayers and these defects could be divided into three types. In addition, the EPDs after annealing at various temperatures were studied. The experimental results showed that suitable thermal annealing can eliminate some dislocations.
Study on the Relations between the Structural Parameters and the Dynamics Properties
Authors: Zhao Deng Feng , Zeng Guo Ying
Published: September 2011

The general rule that the modal parameters of linear system change with the structural parameters was discussed. The calculational method of the change of modal parameters was given on the basis of the current modal parameters and the change pattern variation of structural parameters. An example indicated that this method can greatly save computational time than repeated modal analysis. Withal, the qualitative conclusions of the change of modal parameters can be expediently gained. These results are important to amelioration and optimization design of systems.
Precipitation Behavior and its Effect on Strengthening of High Strength and Toughness Drill Pipe Steel
Authors: Hu Feng , Han Li Hong , Wang Hang , Feng Yao Rong , Li He Lin
Published: September 2011

With the rapid development of oil industry, the high strength-toughness drill pipe suited to the task of sour environment and ultra deep wells would be considered more and more important. A new drill pipe steel, which was designed with the proper decrease of C content and increase of Cr, Ni, Mo, Nb and V alloy element, was developed and studied in this study. The results showed that the yield strength of this new drill pipe steel had reached 150ksi with the impact toughness more than 150J, which can perfectly meet the “leak-before-break” crack principle. Based on the observation of optical microscopy and transmission electron microscopy, several kinds of carbide particles including (Nb, Mo, V)C with nanometer scale, were distributed in tempered sorbite matrix. The objective of this work was to study the relationship between multiple alloy-carbide precipitation and mechanical property of this drill pipe steel.
Effects of Geometry on Aerodynamics of CFO
Authors: Han Bin , Su Zhong Di , Jiang Zhi Cai , Du Zheng , Yin Zhao Qin
Published: September 2011

CFO(Critical Flow Orifice), micro sonic nozzle, is a device in tobacco industry to give a standard gas flow rate. Adopting the blocking effect of the convergent nozzles for compressible fluid, CFO can produce an accurate flow rate in pipe line. CFO can be used in micro flow calibration such as in the measurement of the pressure drop of filter rod or draw resistance of cigarette. To study the effect of convergent shapes on the aerodynamic characteristics of CFO, the 3D numerical simulations are carried out on two kinds of CFO structure shapes with finite volume method, based on the equations of compressible gas. The adopted turbulence model is the realizable k-ε model. According to the results of simulation, using Vyshinsky curve as the convergent curve is better than to apply the cone-shaped curve with the same exit diameter of nozzle. This is difficult to be observed in the experiments. The influence of convergent shapes can provide a basis for optimization design of CFO.
The Effect of the Native Oxidation on the Characteristic of Surface Electron in the In0.13Al0.87N Epilayer Grown by MOCVD
Authors: Zhou Wei , Xia Su Jing , Li Xiang , Yang Jie , Tang Wu
Published: September 2011

The property of surface electron in undoped IIn0.13Al0.87N epilayers with different thicknesses has been investigated using x-ray photoemission spectroscopy (XPS) and micro-Raman scattering spectra. XPS has been used to determine the characteristic of the native oxide at the free surfaces of In0.13Al0.87N film. It is showed that the binding energy shift to higher with the thickness reduction from the Al 2p, N 1s, In 3d5/2 spectra. While, there is more native oxide at the surface of In0.13Al0.87N film with the decrease of thickness. In addition, a broad peak in high energy region was only observed in the thinnest In0.13Al0.87N epilayer from micro-Raman results, and it may be relative to L+ coupled mode of In0.13Al0.87N.
The Finite Element Analysis of Sandwich Variable Cross-Section Plate Bending Performance
Authors: Sun Yu Ping , Min Chun Wei , Li Jin , Teng Zun Li
Published: September 2011

In order to investigate the bending performance of Continuous casting 945 steel sandwich board in cross plate, it is carried out the bending performance numerical simulation for Continuous casting 945steel ,find the largest stress zone in bottom plate when it is at the end of the Elastic stage; Find the most adverse regional、limit bearing capacity、stress-strain relationship and stress three-dimensions degree in the ultimate state. The most unfavorable area of board appeared in middle core board and mid-span junction of sandwich board. When applied 10mm and 90mm displacement, the most adverse regional appeared yield and destruction at first time. According to the stress three -dimensional degree can draw that tension board’s destruction form is stretch destroy in the most adverse regional. When applied limit displacement 90mm, the reaction force is 763.4KN in mid-span. The analysis results note that the most unfavorable area of continuous casting 945 steel sandwich board and destruction form, it has some practical significance for future sandwich board test.
Influence of Temperature on the Densification and Lattice Parameters of Sialon Ceramic
Authors: Tang Zhu Xing , Zhang He , Tan Hui Hui , Zhao Xia
Published: September 2011

The sintering behavior and lattice parameters of β-sialon were investigated by varying temperature, z values and the amounts of sintering additive composed of Y2O3. The experimental results indicated that the z value of β-sialon decreases with the sintering temperature increases. The sinterability of the β-sialon declined with the z values increase . As the sintering temperature rise the phenomenon of anti-densification was occurred when the amount of additive was 7wt%.
Preparation and Microstructure of Pressureless Sintered Si2ON2-SiC Ceramic
Authors: Tan Hui Hui , Tang Zhu Xing , Zhao Xia , Zhang He
Published: September 2011

This paper introduces Si2ON2-SiC ceramic fabricated by pressureless sintering method and studies the effect of additives, nitriding temperatures on bulk density, porosity, phase composition and microstructure. It is discovered that additives MgO, CeO2 can increase the densities of Si2ON2-SiC ceramic apparently, and MgO additive has a better effect than CeO2. Nitriding temperature also is an important factor. The bulk density of the specimen with MgO additive reaches maximum at 1.91 g/cm3 when sintered at 1450 °C, and the bulk density of specimen with CeO2 additive is 1.86 g/cm3 at the same condition while the bulk density of the specimen without additive is only 1.75 g/cSuperscript textm3. The X-ray diffraction and scanning electron microscopy of the specimens show that the amount of Si2ON2 increase with the sintering temperature increase. But when the temperature is higher than 1500 °C the Si2ON2 grains will decompose into Si3N4, and Si2ON2 will vanish at 1550 °C
Technology Research of Silicon Carbide by Extruding
Authors: Tang Zhu Xing , Zhao Xia , Tan Hui Hui , Zhang He
Published: September 2011

The silicon carbide was extruded by the batch and sintered under Nitrogen atmosphere using phenolic resin as the main organic plasticizer. The effect of phenolic resin contents on plasticity of the batch, extrusion force and density of the green bodies and the effect of the solidifying law on mechanical properties of products were studied in this paper. The results are as follows: The density and bending strength of sintered bodies reach 3.11 g/cm3and 320Mpa with 13.6wt% plasticizer content, the extrusion moding can significantly improve the production efficiency and properties of silicon carbide ceramic.
Effects of Monoclinic ZrO2 with Different Particle Size on Properties of Zirconia Refractories
Authors: Sun Hong Gang , Yan Shuang Zhi , Li Peng Tao , Tan Qing Hua , Wu Ai Jun
Published: September 2011

The zirconia refractories were prepared using partially stabilized zirconia grain and monoclinic zirconia powder as the matrix, partially stabilized zirconia particles as the aggregate, and phenolic resin as the binder, and four sizes of monoclinic zirconia powder (D50=1 μm, 3 μm, 6 μm, 10 μm) were used as additives. Besides, an improved specimen was prepared using a specific monoclinic zirconia powder as additive. Properties of specimens with different sizes of m-ZrO2powders were researched, including apparent porosity, bulk density, cold modulus of rupture, pore size distribution. Moreover, phase composition and microstructure were analyzed. The results show that, particle size of monoclinic zirconia powders greatly affect the sintering of materials. The specimens with finer m-ZrO2powder have lower porosity, higher bulk density and cold modulus of rupture, and the grain boundaries of zirconia particles were fuzzy, showing that the matrix of the specimens were almost sintered completely. While in specimens using coarser m-ZrO2powder, the grain boundaries of zirconia particles were clear, showing that the matrix of the specimens were not sintered completely.. Though finer monoclinic zirconia powder promoted the sintering of materials in the test, it had negative impact on the microporus structure, for large pores were observed in the specimen with fine m-ZrO2powder. Finally, the improved specimen with promoted sintering and optimized microstructure as well as phase composition was obtained by using specific monoclinic zirconia powder as additive.
Effect of Si3N4-Nd2O3 Compound Additive on Crystallization and Sintering of Fused Quartz Ceramic Materials
Authors: Shen Shu Bin , Bu Jing Long , Yu Li Xue , Liu Shu Long , Wang Zhi Fa
Published: September 2011

Fused quartz granules (d50=19 μm) were used as raw material, and Si3N4-Nd2O3 (1:1, in mass) was used as additive with dosages of 1% (in mass, similarly hereinafter), 2% and 3%. Fused quartz ceramic materials were fabricated in reduction atmosphere at 1300 °C, 1350 °C and 1400 °C for 1 h. The apparent porosity, bending strength and thermal expansion ratios of the samples were studied and the samples were further analysed by means of XRD and SEM. The results showed that the sample sintered at each temperature with 3% Si3N4-Nd2O3 had the lowest apparent porosity, the highest bending strength and more compact microstructure. This indicated that 3% Si3N4-Nd2O3 was useful to the sintering of fused quartz ceramic materials. The results of XRD and thermal expansion ratio analysis showed that 3% Si3N4-Nd2O3 compound additive had better effect on inhibiting crystallization of the samples sintered at 1300 °C, 1350 °C and 1400 °C.
Study on Transitional Metal Oxides Energy-Saving Materials with High-Emissivity
Authors: Wang Qian Ping , Guo Xiang Xiong , Zhang Jia Sheng , Wu Wei Hua
Published: September 2011

In order to enhance the thermal efficiency of heating and dring facilities, the energy-saving high infrared radiation materials were synthesized by the solid state method for 2h at 950, 1050 and 1150 °C, respectively, and rapid cooling in the air, from transitional metal oxides Fe2O3, Cr2O3, MnO2 andCuO. The strcture and emission property of the samples were characterized through X-ray diffractomete, scanning electron microscop and infrared radiation meter. The results show that the main phases of resultants are spinel ferrites, and with increasing temperature, crystals become better and multiple spinel and like-spinel structures are formed. The infrared radiance represents a nonlinear variation with calcining temperature. The coatings on the stainless steel surface prepared with the materials with self-made binders have good infrared radiation, up to a maximum of 0.90, and have perfect resistance to thermal shock and may arrive at 25 times (RT←→800 °C), exhibiting fairly high binding strength. So the materials which are apply to on the internal wall of heating and drying facilities are believed to result in an long-term energy conservation.
The Microstructure and Properties of ZL116 Alloy Obtained by the Nearby-Liquidus Electromagnetic Casting
Authors: Wei Chun Ying , Wang Ping
Published: September 2011

Studying the microstructures of ZL116 alloy slurry prepared by nearby liquidus electromagnetic casting (NLEMC), electromagnetic casting (EMC), and nearby liquidus casting (NLC) by means of electron microscope and image analysis apparatus. At the same time, determining the their hardness by using hardness instrument. The results show that the NLEMC can obtain the fine and uniform equiaxed grains structure, its average-area-circle grain diameter is 28.5μm, and its rheoforming parts, hardness is 129Hv. All of these also show that the slurry microstructure and rheoforming properties of ZL116 prepared by NLEMC are the best in the three kinds of ways. At the same time, discussing the mechanism of NLEMC structure fine.
EIS Study of Corrosion Behavior of Hot-Dip Galvanized Steel in 5% NaCl Aqueous Solution
Authors: He Shi Quan , Zhong Hui
Published: September 2011

Corrosion behaviour of hot-dip galvanized steel in 5% NaCl aqueous solution was studied by electrochemical impedance spectrum (EIS) technique. The results revealed that corrosion behaviour of hot-dip galvanized steel has a great relationship with immersion time. With the increase of immersion time, corrosion products are constantly changing, and the impedance of corrosion products are different. Parameters fitted by equivalent circuit show that the impedance of corrosion products increased at first, then decreased.
Influence of Sr Addition on Microstructure and Mechanical Properties of Ignition-Proof AZ91D-0.3Be Magnesium Alloy
Authors: Han Fu Yin , Tian Lin Hai , Wang Hong Xia , Liang Wei , Wang Wen Xian
Published: September 2011

Sr added ignition-proof AZ91D-0.3Be magnesium alloy was prepared. The influence of Sr content on microstructure and mechanical properties of the alloy was studied. Results show that the microstructure of ignition-proof AZ91D-0.3Be magnesium alloy is refined by a small amount of Sr addition. It is due to that the enrichment of a few Sr atoms in solid liquid interface in the process of magnesium alloy solidification inhibits grain growth and accelerates more nucleation. However, with increasing of Sr addition the microstructure is coarsened. By 0.01% Sr addition the tensile strength of as-cast experimental alloy is increased by about 25% and that of both the solid-solution and aged alloy is increased by about 40%. The elongation of as-cast alloy is increased by about 20% and that of solid-solution alloy increased by about 30%.
Numerical Analysis and Experimental Results by Silicon-Based MHz Ultrasonic Nozzles to Product of Monodisperse Droplets
Authors: Song Yu Lin , Cheng Chih Hsiao , Lee Chia Fone , Chang Luh Maan , Chou Yuan Fang
Published: September 2011

Monodisperse de-ionized water droplets 4.5 μm in diameter have been produced in ultrasonic atomization using micro electro-mechanical system (MEMS)-based three-Fourier horn 1 MHz silicon nozzles. The required electrical drive power and voltage are 15 mW and 6.5 V, respectively. The nozzles measure 1.80 x 0.21 x 0.11 cm3 and can accommodate flow rate of 2 to 300 μl/min. As liquid enters the 200 μm x 200 μm central channel of the nozzle, a curved thin liquid film is maintained at the nozzle tip that vibrates longitudinally at the nozzle resonance frequency, resulting in formation of standing capillary waves on the free surface of the liquid film. As the tip vibration amplitude exceeds a threshold (critical or onset amplitude), the standing capillary waves become unstable (temporal instability) and a spray of monodisperse droplets (mist) is produced. The experimental results of resonance frequency, droplet diameter, voltage requirement and critical or onset amplitude support the predictions of the three-dimensional finite element simulation and the linear theory of capillary wave atomization mechanism.
Optimization Parametric Study of Deep Drawing Process for a Standardized Cranial Implant
Authors: Sena Khemajit , Piyasin Surasith
Published: September 2011

The purpose of this study is to investigate the optimal process parameters use to fabricated a standardized cranial implant using deep drawing with a titanium mesh sheet. First, the mold for deep drawing, consisting of die, punch, blankholder and blank sheet, was designed within a CAD program. Then the formability of the mold was simulated using FE software. Furthermore, a link between the result of the FE simulation and CAE program was established to determine the best input parameters in the deep drawing system which produced minimal defects (wrinkles and ruptures). The parameters of interest in this study were the overall friction coefficient, blankholder friction coefficient, blankholder force and blank sheet thickness. The results showed the high feasibility of the joint CAE program and optimization procedure to calculate the best input parameters which can reduce time and cost consuming physical tryouts.
Peritectic Reaction of High Nb and W Pentatomic TiAl-Based Alloy
Authors: Sun Hong Liang , Sun Cai , Huang Ze Wen , Zhu De Gui
Published: September 2011

The effect of different aluminum content on peritectic reaction and mechanical properties of pentatomic TiAl-based alloy was investigated. The results indicate that the grain size gradually increase with increasing content of aluminum and addition 45.7% aluminum in TiAl-based alloy results in that the peritectic reaction can increase grain size greatly, respectively. The content of aluminum can increase the room temperature strength, high temperature strength but peritectic reaction can effectively reduce tensile strength. Aluminum content has a little effect on the ductility. The stress rupture life has positive correlation relationship with the content of aluminum.
Synthesis and Properties of Polyurethane Modified with Hydroxyl Terminated Polysiloxane
Authors: Tian Jun Ling , Cao You Ming , Zhou Xiao Tao
Published: September 2011

A series of silicone modified polyurethane(Si-PU) block polymers were synthesized from using polybutylene adipate (PBA), methane-4-4’-diisocyanate(MDI), 1,4–butanediol(BDO) and hydroxyl terminated polysiloxane(HO-PDMS). The effect of synthesis condition on the shear strength was investigated. The influnce of the content of HO-PDMS on the absorption properties of PU was tested. The structure of the synthetic products was characterized by Infrared Spectrum, the surface hydrophobicity was examined by surface contact angle and the scanning electron microscopy(SEM), respectively. The results showed that the silicone chain segments were incorporated into PU macromolecule. The shear strength firstly decreased slightly and then decressed greatly with increasing the HO-PDMS content. But the modified polyurethane had low surface energy, surface water contact was improved by 25°C, and the water resistance was also improved.
Crystallinity and Mechanical Properties of PLA/POE Blends
Authors: Zhou Jin Tang , Yao Zheng Jun , Zhou Juan Juan
Published: September 2011

The crystallinity of PLA which was blended with POE and POE-g-MAH together with main mechanical properties were studied. Contact angles increase in the following sequence: PLA, POE-g-MAH, POE. The crystallinity of PLA which were blended with 5 wt% POE is higher than untreated PLA while POE-g-MAH bring down the crystallinity of PLA. For POE, The 15 wt% portion in the blend with PLA is enough to make optimal toughness. Tensile strength of the blends is not decline but increase a little when POE is used in small amount (less then 5wt%) on account of the high crystallinity. All of those lead to a result that not only the tougher, but also the crystallinity of PLA itself play important role in mechanical properties of the blends.
Study on Preparing Light Colored C9 Petroleum Resins with High Softening Point
Authors: Yang Li Min , Zhang Hong Hui , Wang Jia Hao , Hu Min
Published: September 2011

Polymerizable C9 fraction was cut by atmospheric distillation of raw C9 fraction from thermal cracking. The obtained fraction polymerized using boron trifluoride ethyl ether as catalyst and then the polymerized mixture was washed by warm 10%wt Na2CO3 aqueous solution and distilled water and separated by vacuum distillation for producing light colored C9 petroleum resins with high softening point. The suitable conditions for polymerization process, washing process, vacuum distillation process were investigated to improve the C9 petroleum resins production. Under these conditions, the petroleum resins product with Gardner color index of 4-5 and softening point of 102-120°C could be obtained.
Application as Papermaking Retention Agent of Water in Water Cationic Polycaylamide in Bleached Soda Reed Pulp
Authors: Ma Yong Sheng , Sun Xian Hui
Published: September 2011

The application of water in water cationic polyacylamide emulsion (CPAM) was studied used in bleached soda reed pulp. The main effects, such as adding amount of CPAM, the dosage of sulfate aluminium, pH value of the bleached soda reed pulp, reaction time after adding the CPAM and the concentration of the electrolyte were discussed here in detailed. The optimal application conditions of CPAM in bleached soda reed pulp were finally gained-CPAM 0.04% relative to dry fiber, 2 minutes for reaction, whip velocity 200r/min, sulfate aluminium 3%relative to dry fiber, pH value 4.0 and sodium chloride 0 relative to dry fiber.
Synthesis, Spectra and Bond Studies on a Novel Cu-Ru Complex of Magnetic Dilution
Authors: Wang Wen Zhen , Li Yan , Liao Dai Zheng
Published: September 2011

A novel complex [Ru(phen)3][Cu(opba)]‧6H2O has been prepared and characterized structurally. The crystal structure showed that the complex consisted of dication [Ru(phen)3]2+and complex dianion [Cu(opba)]2–. The IR, Uv-vis, EPR spectra were studied, and EPR spectra showed hyperfine structure from copper isotopes63Cu and65Cu, and superhyperfine(shf) from14N coupling, giving parameters g// = 2.207，g = 2.026，A//Cu= 196 G，ACu= 43 G，A//N= 13 G，AN= 17 G. The bond parameters were evaluated based on the EPR spectra, indicating substantial π-bonding character in the Cu–N and Cu–O bonds in the complex [Cu(opba)]2–. The spin density on nitrogen and oxygen atoms is 0.081 and 0.195, respectively.
Effect of Surfactants on Modifying the Surface of Magnetic Nanoparticles by Thermal Decomposition
Authors: Shao Hui Ping , Lin Tao , Luo Ji , Guo Zhi Meng
Published: September 2011

The nanosize magnetic particles were synthesized by thermal decomposition method with size distribution in the range of 10 ~ 30 nm. Different category and quantity of surfactants were used modifying the surface of the synthesized nanoparticles to control the particles’ shape and size. Multi-shapes, such as uniformity cubic, mixture of spherical and cubic, and the similar chick footmarks, were acquired in our experiment by different surfactants. It indicates the surfactant is a key factor for the size and shape of particles. The surfactants of PVP and oleylamine made the particle shape be uniformity cubic; However, the particle partly behaved as spherical shape in the case of using PVP and oleic acid as surfactants.
Low Temperature Sintering of Ca0.6La0.8/3TiO3-Li0.5Nd0.5TiO3 Ceramics with ZnO-B2O3-SiO2 Glass Addition
Authors: Gu Yong Jun , Huang Jin Liang , Hu Wei , Li Qian , Li Li Hua , Xu Hui
Published: September 2011

The sintering behaviors and microwave dielectric properties of the Ca0.6La0.8/3TiO3-Li0.5Nd0.5TiO3 (abbreviated CLLNT) ceramics doped by small amounts of ZnO-B2O3-SiO2 glass were investigated in this paper. The adding of ZnO-B2O3-SiO2 glass improved the densifications of the CLLNT ceramics and the sintering temperature of the CLLNT ceramic had been efficiently lowered to 1050°C. Especially, the 8wt% ZnO-B2O3-SiO2 glass doped CLLNT ceramic sintered at 1050°C for 3 h has optimum microwave dielectric properties of Kr=89, Q×f=1445GHz, and TCF=11.4 ppm/°C and it should be a suitable candidate for LTCC applications.
Effects of Low Concentration BiFeO3 Additions on Microstructure and Piezoelectric Properties of (K0.5Na0.5)NbO3 Ceramics
Authors: Xu Peng , Jiang Min Hong , Liu Xin Yu
Published: September 2011

(1- x) K0.5Na0.5NbO3 – x BiFeO3 lead-free piezoelectric ceramics were prepared by the conventional ceramic processing. The compositional dependence of the phase structure and the electrical properties of the ceramics were studied. A morphotropic phase boundary (MPB) between the orthorhombic and tetragonal phases was identified in the composition range of x = 0.01. The ceramics exhibit a strong compositional dependence and enhanced piezoelectric properties. The ceramics with 0.6 mol.% BF exhibit good electrical properties (d33 ～146 pC/N, kp ～51%, Tc ～405°C, To-t ～185 °C, εr ～432, and tan θ～ 4.60 %. The related mechanism of the enhanced electrical properties of the ceramics was also discussed. These results show that the air-sintered (1−x) KNN− x BF (0.006 < x < 0.01) ceramic is a promising lead-free piezoelectric material.
Preparation and Luminescence Properties of the Nano- Composite Materials LaF3 - SiO2: Eu3+
Authors: Wang Xi Gui , Wang Xiao Xian
Published: September 2011

Eu3+doped LaF3-SiO2nano-composite material were synthesized by sol-gel method at room temperature, and the structure and properties were characterized by XRD, TG-DTA, IR, excitation and emission spectrum. The structure indicated that the optimal doping formula for preparing nano-materials was La5Si95that transformed into a stable mineral structure of cerium fluoride, and mainly found Si-O-Si bonds when the temperature was above 500 °C. Luminous property researches showed that the optimum annealing temperature was 500 °C. The best excitation wavelength was 395 nm when the monitoring wavelength was 612 nm, and the optimal doping molar concentration of Eu3+was 0.35 mol %.
Effect of Plasticizer of Sizing Agent on the Surface of Carbon Fibers and Interface of its Composites
Authors: Zhang Huan Xia , Cao Amin , Luo Yong Kang , Wei Li
Published: September 2011

In this work, carbon fibers were sized with different plasticizer of sizing agent in order to improve the performances of carbon fibers and the interface of carbon fibers composites. The chemical and physical changes induced by the treatments on carbon fibers surface are examined using dynamic contact angle analysis test(DCAT) , X-ray photoelectron spectroscopy (XPS). The interfacial shear strength (IFSS) of CF/EP composites are analysised by micro-droplet test. At the same time, the wear resistance was also studied in order to understand the effect of the plasticizer of sizing agent on the carbon fibers. The study shows that the 3# sized carbon fiber has the better wetting and surface energy. XPS results reveal that the 3# samples show a significant increase in oxygen-containing groups, such as–C–OH, -COOH, -C–O–C- and -COOR. 3#sizing agent also show better interface adhesion between fibers and matrix and has better wear resistant properties.
Study on a Quinoline Inhibitor Used for Sulfur Corrosion on Carbon Steel: Properties Research and Field Test
Authors: Han Ye , Cui Zhen Duo , Liu Zhao Zeng , Chen Zhao Long , Ba Lin , Wei Qiang , Zhu Sheng Li , Yang Xian Jin
Published: September 2011

Inhibitors are frequently used for controlling sulfur corrosion in oil and gas production due to its low cost, easy operation and significant effects. In this study, a corrosion inhibitor TD-02 was prepared, and the properties of TD-02 were investigated by weight loss, SEM and electrochemistry measurements in saturated hydrogen sulfide solution. The results show that significant inhibition effect was achieved by adding TD-02 as inhibitor. A protective film is formed by adsorption of inhibitor molecules on the matrix and inhibition achieved by geometry covering. The field test results indicated that the wear of the compressor shaft was significantly inhibited, which achieves the desired results.
Effect of Cassava Starch Destructuration to Mechanical Properties of Compostable Blends
Authors: Thongtan Roung Rong , Sriroth Klana Rong
Published: September 2011

Pregelatinized and oxidized cassava starches were proven to be satisfactory to be distributed into poly(lactic acid) and poly(butylene adipate-co-terephthalate) mixture in order to obtain relatively inexpensive compostable material with acceptable properties. Thermoplastic starch from cassava appeared to effectively plasticize the mixture, particularly by pregelatinized starch which underwent complete granular destructuration. The destructuration allowed free hydroxyl groups in starch molecules to bind with free water and resulted in larger free volume which enhanced molecular mobility and, hence, the elongation. However, the destructuration of starch granule accelerated the dissolution of material in water and enhanced water sorption into the blend material.
Numerical Simulation on Temperature History during Cooling Process of Wire Rod
Authors: Chen Chao , Ding Cui Jiao , Ouyang De Gang , Chen Sheng , Song Zhong Hua
Published: September 2011

A one-dimensional mathematical model of wire rod during cooling was developed. This model considered the heat of phase transformation during the cooling process. Based on the energy-balance method the equations were calculated, and the temperature history during cooling process of wire rod was obtained. The comparison of the calculated results with the measured results showed that the model worked well for simulating the temperature history of wire rod during cooling process. The effects of roller speed, diameter of wire and fan delivery on temperature history of wire were analyzed. With this developed model, the optimizing of cooling processes of wire rod can be investigated in the future.
Time-Varying Characteristics of Bending Deformation of Work-Piece in the Turning Process
Authors: Li Shun Cai , Meng Hua
Published: September 2011

Based on the geometrical description of work-pieces cutting process, the time-varying differential equations of deflection curve under two different conditions were obtained using the singular function: one with thimble and one without thimble constraint. Using the Mathcad software, we have solved the time-varying differential equations analytically and have studied the deflection changing of work piece with the position of turning tool and given the distribution characteristic for the time-varying deflection of each section. The results indicate that (1) the deflection of an arbitrary section is time-varying due to the time-varying position of the turning tool and the time-varying inertia moment; (2) for the shaft with thimble constraint, the position of the maximal deflection is not at the section with turning tool; (3) for the shaft without thimble constraint, when the turning tool is at the free end, the deflection at each section of the work-piece is the maximal compared with the other positions of turning tool.
Effect of Cold Reduction Ratio and Annealing Temperature on Microstructure and Mechanical Property of 240MPa Grade High Strength if Steel
Authors: Wang Min Li , Xiao Li , Zheng Zhi Wang
Published: September 2011

Hot rolled 240MPa grade high strength IF steel sheet was used to study the effect of cold reduction ratio and annealing temperature on the microstructures and mechanical properties of experimental steel. The experimental results showed that the recrystallization has finished under different annealing temperature followed 75% to 85% cold reduction ratio. To the experimental steel of high coiling temperature, The yield strength, tensile strength ,elongation percentage, yield point elongation, the plastic strain ratio and strain hardening exponent were approximate 260MPa, 445MPa, 37.5%, 2.14%, 0.25, 2.0. To the experimental steel of low coiling temperature, that were approximate 235MPa, 369MPa, 38.8%, 1.73%, 0.26, 2.1. Therefore, the suggested the optimal annealing temperature is 840 °C, cold reduction ratio is 75%, and it obtains optimally match of high strength and punching property.