bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of CAD/CAE/CAM Technology in Plastics Injection Mould Design and Manufacture
Authors: Dai Ming He , Yun Zhi Dong
Published: December 2011

The process of injection mould design and manufacture was introduced by taking the cover as an example. Firstly, the 3D model of the part and the injection mould structure were designed based on SolidWorks software. Secondly, the injection molding progress was analyzed and simulated based on Moldflow software. Finally, the toolpaths of cavity and core were designed based on MasterCAM software, and its manufacture process and numerical control programming was simulated. The period of product development was shortened effectively and the quality of design and manufacture was improved by CAD/CAE/CAM integrated technology.
Fatigue and SCC Behavior of Sensitized SUS304 Stainless Steel in Pressurized Hot Water at 7.3MPa and 288°C
Authors: Saengsai Anchalee , Otsuka Yuichi , Mutoh Yoshiharu
Published: December 2011

Plain fatigue and fretting fatigue tests of sensitized SUS304 stainless steel under pressurized hot water at 7.3MPa and 288°C have been carried out. Fatigue strengths for both fatigue tests almost coincided. Fretting contact could nucleate small SCC cracks near the contact edge in the direction perpendicular to cyclic loading. High R–ratio reduced fatigue strength due to longer exposure time to corrosive environment at high mean stress. From the constant load SCC tests of the specimen with small SCC pre–crack induced by fretting contact, it was found that the threshold stress intensity factor for growth of small SCC precrack was 4.1MPa·m1/2, which was significantly lower than that for long crack (10MPa·m1/2).
Microstructure and Mechanical Properties of 60Si2Mn Steel after Austenite Inverse Phase Transformation by Sub-Temperature Quenching
Authors: Li An Ming , Hu Meng Juan
Published: December 2011

Microstructure and mechanical properties of 60Si2Mn steel by 870 °C prequenched and second sub-temperature quenching was studied. The results showed that the hardness of the 60Si2Mn steel first increased and then decreased with increasing second sub-temperature quenching temperature, and the highest hardness was obtained when sub-temperature quenching temperature was 800 °C.The sample after second sub-temperature quenching was composed of martensite and a little ferrite phase. The abundance of ferrite phase decreased with the increase in second sub-temperature quenching temperature. Fine martensite was obtained by second sub-temperature quenching, which may be relate to the grain refinement of austenitic phase and austenitic nucleation sites. The mechanical properties of the 60Si2Mn steel after 870 °C prequenching and second sub-temperature quenching are better than that of conventional samples after 870 °C quenching.
An Optimization Method for Optimal Engineering Structure Design Combining Intelligent Optimization Algorithm and CAE Code
Authors: Peng Wen Jie , Ge Rui , Gu Ming Kai
Published: December 2011

This paper presents an optimization method for optimal engineering structure design. An interface procedure is essentially developed to combine the intelligent optimization algorithm and computer aided engineering (CAE) code. An optimization example is carried out to minimize the interlaminar normal stress of a laminate which affect the delamination failure of a laminate via arranging the stacking sequence. The analytical solution is calculated to validate the accuracy of optimization results.
Surplus Fatigue Life Prediction of Diesel Engine Piston by the Equivalent J-Integral Approach
Authors: Zhang Wen Xiao , Gao Guo Dong , Mu Guang Yu
Published: December 2011

Three dimension temperature fields and stress-strain fields of the 6110-type diesel engine piston were analyzed by using the program ANSYS. The simulating tests of crack propagation under high temperature low cycle fatigue were carried out with pre-crack notched specimens. According to the theory of high temperature strength and fracture, the equivalent J-integral range ΔJf were induced to predict the surplus fatigue life of diesel engine piston. It was concluded that this approach is suitable and provides valuable reference for designers of diesel engine.
Study on Microstructure and Mechanical Properties of Newly Developed High Carbon Fe-Mn-Cu-C TWIP Steels
Authors: Song Wei Tao , Zhu Ding Yi , Liu Hai Jun , Huang Fen Fen
Published: December 2011

The effects of high carbon content on the microstructure and tensile properties of Fe-20Mn-3Cu-xC TWIP steels were studied by OM, XRD, SEM analysis. The experimental results indicate that the amount of carbide and micro-porosity increased with the increasing of carbon content. The microstructures in the undeformed and deformed region of Fe-20Mn-3Cu-xC steels exhibit fully austenitic phase. The fractography of tensile samples reveals typical tough fracture microstructure with isometric dimples. The number of carbide in the as-cast structure, the yield strength and the tensile strength increase with the increasing of carbon addition, but the elongation rate increases at first and then decreases. TWIP steel has the optimum property when the carbon addition is 1.3 mass pct, of which the tensile strength is 1040.59 MPa, the elongation percentage is 98.08% and the strength-elongation product achieves 102061.07MPa•%. Fe-20Mn-3Cu-xC steels have high strain hardening capacity, and strain hardening rate (θ) and strain hardening index (n) both increase with the increasing of C addition.
High Temperature Deformation Behavior of 25Cr5MoA Nitriding Steel
Authors: Zang Yue , Li Shu Xia , Yang Yi Kun , Ren Xue Ping
Published: December 2011

The high temperature deformation law of nitriding steel 25Cr5MoA over the strain rate range 0.001S-1~20S-1and temperature range 850°C to 1150°C was studied in the thermal simulation testing machine Gleeble-1500. Under a certain strain rate and a certain deformation degree, the flow stress decreased with the increase of deformation temperature. Work hardening of nitriding steel 25Cr5MoA was strong when the true strain was less than 0.2, otherwise the flow stress increased slowly, even dropped. High temperature deformation flow stress of nitriding steel 25Cr5MoA was influenced by the deformation temperature and strain rate. When the strain rate was 0.1S-1, true stress-true strain curve exhibited a dynamic recrystallization model, and with the increase of deformation temperature, peak flow stress shift left. When deformation degree was 0.69, the strain rate was 1S-1, and when deformation temperature was in the region of 850°C~1050°C, true stress-true strain curve exhibited a dynamic recovery model. And when the deformation temperature was in the region of 1100°C~1150°C, it showed a dynamic recrystallization model. Dynamic recrystallization diagrams of nitriding steel 25Cr5MoA were also established.
Effects of Different Manganese Content on Microstructures and Properties of TWIP Steel
Authors: Wang Li Hui , Tang Di , Jiang Hai Tao , Liu Ji Bin , Chen Yu
Published: December 2011

By analysis of TWIP Steels with different manganese content, the results showed that the microstructures and properties had been changed with different Mn content. The elongation of the tested steel with 22.5% Mn was high for 55.5 % and n value of that reached to 0.360. When Mn content of the tested steel was 17.9%, the yield and tensile strength were higher and its elongation was lower for the tested steel than that of the tested steel with 22.5% Mn. The microstructures of the tested steel with high Mn content were austenite before and after being stretched at room temperature. Mn content was decreased and the microstructure of the tested steel after being stretched had a small amount of martensite transformation at room temperature. That is to say, double effect with TWIP and TRIP had occurred, but TWIP effect was dominant. TWIP effect increased plasticity and strain hardening capacity to improve formability. TRIP effect was mainly to improve strength so as to further attain the strength of the tested steel.
Effects of Ca on Microstructure and Properties of Spray Deposited RE Mg-Al-Zn Alloy
Authors: Wang Tong Le , Li Zhen Liang , Ren Hui Ping , Wang Yu Feng , Chen Wei
Published: December 2011

Magnesium alloy of 6% Ca and 9% Ca, produced by spray deposited method, was heat treated at different solid-solution and the same aging treatment. The microstructure and hardness were analyzed by SEM, XRD and HV tester. The experimental results showed that Ca can make the spray deposited magnesium matrix grains refine uniformly, the second phase particle Al2Ca and CaZn are formed and the hardness value increase. With the rise of solution temperature, the hardness of 6%Ca and 9%Ca magnesium alloy rise firstly and then fall, and the hardness value of 6%Ca increase to the highest 121Hv and 9%Ca increase to the highest 128Hv after 370°C/3h+205°C/24h.
Microstructure and Texture Comparison of an Acicular Ferrite Pipeline Steel with Different Hot Rolling Process
Authors: Wang Hai Yan , Ren Hui Ping , Han Le , Jin Zi Li , Sun Hao
Published: December 2011

Microstructure of X80 pipeline steel with different hot rolling process was compared using Optical microscopy (OM), Bulk X-ray texture and micro orientation analysis was carried out by Orientation distribution function (ODF) and Electron back-scattered diffraction (EBSD), to analyze the various texture components of the pipeline steels under two different rolling processes. The results show that the final microstructures under the two schedules both present typical acicular ferrite characteristic. On the other side, the corresponding textures were found mainly comprised of two fibers in the rolling and normal direction in hot rolled X80 steel plate, there were obvious {112} , {110} , and {111} fiber, which seemed to be related with the mechanical properties anisotropy. Therefore, the influences of the microstructure and texture on the anisotropy were also discussed in this paper.
Orthogonal Test on Heat Treatment Parameters of Modified Low Chromium White Cast Iron
Authors: Liu E , Wei Feng Lan , Qiu Li Chun
Published: December 2011

The effect of austenitizing temperature, heating time and tempering temperature on hardness and impact toughness of low chromium white cast iron was studied by orthogonal test. The optical microstructure was used to analyze the reasons of changes on mechanical properties. The results showed that the hardness increases at beginning and then decreases with the increase of each parameter, high impact toughness can be obtained at high tempering temperature and high austenitizing temperature, the descending order of influence on hardness and impact toughness is austenitizing temperature, heating time, tempering temperature.
Mechanical Properties and Microstructure of SS400 Friction Stir Welds Pursuant to Welding Distance
Authors: Lee Kwang Jin , Park Hyun Kuk , Kim Sang Hyuk , Park Hyun Kuk , Oh Ik Hyun
Published: December 2011

FSW have advantage as defect such as porosity, metallic compounds decrease than other welding process. So, FSW was researched about low melting point materials. However, welding of high melting point and high strength materials attract attention because of high mechanical properties was needed due to industrial development. In this study, FSW is enforced using the kind of high melting point materials as SS400(SPHC). However, the tool must have super heat-resisting and abrasion resistance. So, WC-X%Co tool was manufactured by SPS method. The result, welding is successfully practice using WC-X%Co tool to 50m without fracture of tool.
Isothermal Section of the Zr-Sn-Nb System at 450°C in Zirconium Rich Corner（Zr≥55 at.%）
Authors: Tang Yi Yuan , Ma Fu Hua , Jiang Hua
Published: December 2011

Zirconium rich corner’s isothermal section of the Zr-Sn-Nb system at 450°C was determined by using X-ray diffraction. Experiment results showed that this isothermal section consisted of 2 three-phase region: ((βNb) + Zr4Sn + (αZr)) and (Zr4Sn + (βNb) + Zr5Sn3), 3 two-phases region: ((βNb) + (αZr)), (Zr4Sn + Zr5Sn3) and (Zr4Sn + (αZr)), and 4 single-phase region: (βNb), (αZr), Zr4Sn, Zr5Sn3.
Anodic Surface Treatment on Carbon Fibers - The Effect on Microstructure of Pyrocarbon Matrix during Chemical Vapor Deposition
Authors: Chen Jie , Yu Shu , Xiong Xiang
Published: December 2011

Before chemical vapor deposition, PAN-based carbon fibers were modified by anodic surface treatment for different time, using 5% ammonium bicarbonate as electrolyte. Effects of the surface treatment on surface mophology, chemical functional groups of carbon fibers were investigated. The microstructure of pyrocarbon were analysed as well. The results show that the anodic surface treatment by 5% ammonium bicarbonate for proper time can improve the surface morphology and adjust the surface functinal groups of carbon fibers, which can promote the deposition of ordered pyrocarbon during chemical vapor deposition.
Mechanical Properties of Sandwich Structure Composites
Authors: Zhang Jian She , Li Di Hong , Liang Cheng Li , Jia Jiu Si , Zhang Dong Xing , Tian Ye , Xiao Hai Ying , Jia Jin
Published: December 2011

Flat crush performance test, edgewise compressive properties test and sheering properties test of both ripple structure and latticed structure sandwich composites were performed respectively. Test value of elastic modulus was obtained. Contrastive analyzing the test value and calculated value, the correctness and feasibility of equivalent mechanical model were testified.
Preparation and Properties of Bagasses Cellulose Microcrystal Reinforced Poly(Vinyl alcohol) Composite Film
Authors: Li Chun Guang , Zheng Bin Guo , Peng Wei Gong , Tian Wei , Zhang Rui
Published: December 2011

The biodegradable composite films were prepared from bagasse microcrystalline cellulose as filler and poly(vinyl alcohol)(PVA) as polymeric matrix. The crystallinity, the tensile properties and the thermal properties of the composites were tested. Bagasse microcrystalline cellulose was distributed in PVA films as the crystalline state. The results show that the tensile properties and thermal properties were improved with the addition of bagasse microcrystalline cellulose. When bagasse microcrystalline cellulose mass fraction was 5%, both temperature of initial decomposition and maximum weight loss rate of composite film were raised by 11.71°C and 36.86°C, and the tensile strength increased by 17.88%, and the elongation at break increased by 36.62% compared to those of pure PVA.
Microstructure Evolution and Mechanical Properties of Mg2B2O5 Whiskers Reinforced AZ31B Magnesium Composites Extruded at Elevated Temperatures
Authors: Zhu Yun Peng , Jin Pei Peng , Zhao Pei Tang , Fei Wei Dong , Wang Jin Hui , Han Li
Published: December 2011

The microstructure evolution and mechanical properties of Mg2B2O5 whiskers reinforced AZ31B magnesium composite during extruded were investigated using optical microscope and scanning electron microscope. Mg2B2O5w/AZ31B was fabricated by stir-casting and the as-cast ingot was machined into cylindrical billets. Then the hot extrusion was carried out at 350°C at a constant speed of 10 mm/s with extrusion ratio of 6.25:1. The mechanical properties (strength, ductility and hardness) were tested by tensile tests and hardness tests at room temperature. Typical microstructures of different positions of extruded stock showed the microstructure evolution law during extrusion processing. It was found that DRX took place and whiskers accelerated DRX during hot extrusion. The whisker distribution in the composites was improved by hot extrusion. Additionally, the vickers microhardness of the composites increased first, and then decreased with deformation degree increased.
Preparation and Characterization of a Novel Flame Retarded MCA-PA6 Resin by In Situ Polymerization
Authors: Mu Jun Qian , Yang Yi , Peng Zhi Han
Published: December 2011

In this paper, a novel flame retarded MCA-PA6 (PA6 incorporated with melamine cyanurate) resin was synthesized by in-situ polymerization. The synthetic product was characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM), Fourier transform infrared spectroscope (FTIR), thermogravimetry analysis (TG), differential scanning calorimetry (DSC) and elemental analysis. The result showed that good dispersability were obtained in MCA-based PA6 prepared successfully. Meanwhile, the maximum mass loss rate appeared at about 450 °C and the residual char increased from 1.2 wt% to 3.2 wt% at 500 °C due to the existence of MCA.This research revealed MCA-PA6 owned a good thermal stability, hence there was potential flame retardance.
Effect of Surface Treatment on the Mechanical Property and Micro-Structrue of Polypropylene/Attapulgite Composites
Authors: Xu Li Li , Long Tao , Liu Sheng Peng
Published: December 2011

Attapulgites (AT) were modified by coupling agent 3-(trimethoxysilyl) propyl methacrylate ( KH570 ). Then, the modified AT (MAT) and unmodified AT particles were compounded with Polypropylene (PP) to prepare PP/MAT and PP/AT composites respectively. Their structure and properties were characterized by mechanical testing, differntial scanning calorimetry (DSC) and Scanning electron microscopy (SEM). The results showed that the tensile strength of PP/MAT and PP/AT composites were both improved by filling of 1~7 wt% AT particles. The izod impact strength of PP/MAT composites were increased obviously than that of PP/AT composites with AT content of 1~7 wt% , and it attain the most at 1 wt% filler loading. The crystallization temperature of PP/MAT composites was increased than that of PP/AT composites and pure PP. The degree of supercooling was decreased indicates that the crystallization rate of polymer is improved. The crystallization rate of the PP phase is enhanced in the PP/MAT composites due to the introduction of homogeneous dispersed AT modified by KH570 and good interface adhesion between the AT and PP matrix.
Generic Geometric Model for 3D Woven Interlock Composites
Authors: Mahmood Ansar , Wang Xin Wei , Zhou Chu Wei
Published: December 2011

The mechanical properties of 3D woven interlock composites (3DWIC) can be tailored via design of their weave architecture. This paper presents a geometric model called Generic Geometric Model (GG-Model) which delineates the weave architecture of 3DWIC based on its realistic internal geometry i.e. geometry of the cross-section and path of tows. In GG-Model, the cross-section of tows has been described through a novel shape function called “Generic Shape Function (GSF)”. The GG-Model uses manufacturer and weaver specified data to calculate geometric parameters of the 3DWIC and the reinforcing fabric. The GG-Model is then validated by comparing modeled parameters with experimental data. Strong correlation is found between modeled parameters and experimental data.
The Influence of Clay-Like Sepiolite on the Structure and Properties of Polyurethaneurea/Sepiolite Nanocomposites
Authors: Lu Hui Zhen , Yi De Lian , Chen Hong Xiang , Zhou Yu , Zhang Jin Long
Published: December 2011

A series of polyurethaneurea (PUU) nanocomposites based on clay-like sepiolite (Sp) with the modification of γ-aminopropyltriethoxysilane (KH550) were prepared via in situ polymerization from poly(propylene glycol), tolylene-2,4-diisocyanate (TDI) and 3,3'-dichloro-4,4'- diamino-diphenylmethane(MOCA). Morphology and structure of nanocomposites were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The results indicated that KH550-Sp was dispersed homogeneously in the PUU matrix, which facilitated the formation of chemical bonds between KH550-Sp and the hard segment of PUU. The thermostability and mechanical properties were studied by the thermogravimetric (TG) analysis and tensile tests. The results showed that the onset decomposition temperature and tensile strength of nanocomposites was higher than those of pure PUU.
A Novel Nonionic, Multi-Surfactant System and Separation Method for the Synthesis of Active Carbonic Anhydrase Nanoparticles
Authors: Nie Guo Chao , Si Di , Kim Gwang Seong , Shi Zhong You , Ratani Tanvi Siraj , Lee Yong Eun Koo , Kopelman Raoul
Published: December 2011

This paper describes a new synthesis and separation method of nanoparticles (NPs) using a non-toxic, non-ionic surfactant systems. The purification steps did not use ethanol or acetone. Results indicate that the wild type bovine Carbonic Anhydrase (CA) activity was enhanced almost 4 times more than the CA encapsulated NPs fabricated by the traditional method. The NPs have are more hydrophilic and also have a higher zeta potential. The well dispersed CA PAA NPs with of 10-30 nm in diameter were obtained. This work also demonstrates a universal method for immobilizing fragile biomacromolecules in NP carriers for biomedical applications.
Influences of Tm and N Doping on Surface Properties and Photoactivities of Anatase-TiO2 Nanoparticles
Authors: Lu Zhi Yu , Jiang Hong Quan , Yan Pan Pan , Li Jing Shen , Wang Qing Yuan
Published: December 2011

Mesoporous anatase-TiO2nanoparticles mono-doped and co-doped with thulium and nitrogen were synthesized via a modified sol-hydrothermal method, and characterized by XRD, BET, XPS, FT-IR, DRS and PL techniques. The results showed that the Tm-doping inhibited both the transformation from anatase to rutile phase and the recombination of photogenerated electron-hole pairs, as well as increased the content of surface hydroxyl group, then improved the UV photoactivity of TiO2. The N-doping led to forming the N–Ti–O and N–O–Ti structures, which narrow the electronic band structure, then improved the photoactivity in the visible light region. However, the best visible light photoactivity for degradating methylene blue (MB) in aqueous solution was obtained in the N-doped sample instead of the co-doped sample, implying that no synergetic effect rises from Tm and N co-doping.
Morphology Evolution during Annealing and Electrical Conductivity of Titania Nanotube Films
Authors: Xiong Jian Yu , Wang Yu , An Yang , Wen Ming , Ding Yun Fei , Li Yun Cang , Hodgson Peter
Published: December 2011

Titania nanotube films were produced by anodization of titanium foil. The titania nanotube films were annealed at different temperatures. Morphology evolution, phase transformation and electrical conductivity of the titania nanotubes were studied. Results showed that the nanotube walls became rough, porous and even collapsed after annealed at 400, 500 and 600 °C respectively. Titania anatase phase formed after annealed at 400 °C; the amount of anatase phase increased as the annealing temperature increased. The conductivity of the nanotube film annealed at 400 °C was improved greatly compared with the conductivity of the as-anodized nanotube film. However, the conductivity of the nanotube films annealed at higher temperatures decreased. The effect of the morphology on the electronic conductivity of the titania nanotube films was discussed.
Effect of Ultrasonic Cavitation Acting on Solidified Structures of 7050 Aluminum Alloy
Authors: Zhang Li Hua , Hu Qian Qian
Published: December 2011

Imposing ultrasound on D.C.casting of the 7050 aluminum alloy could refine grains significantly. Among the physical effects accompanying the propagation of high power ultrasonic oscillations in melt, cavitation, or the formation of cavities filled mainly with gases dissolved in the molten melt. In this research, we have analyzed solidified structures which influenced by different power of ultrasound via using cavitation theory and experiment. The results indicated that after treating by ultrasound, the solidified structures of the aluminum alloy could be refined considerably and the degree of the structure refining rose along with the increase of the ultrasound power. Software MATLAB was chosen to simulate the relationship between acoustic pressure and relative radii of cavitation bubbles, ultrasonic frequency and relative radii and initial equilibrium radii and relative radii respectively. After that, the mechanism of grain refining have been discussed under the condition of stable cavitation and transient cavitation, providing some related references for ultrasound applying in the field of foundry industry.
Synthesis and Microwave-Absorbing Properties of Ni-Carbon Sphere Composites
Authors: Zhang Yuan Guang , Xia Hong Yu , Zhao Ying Guo
Published: December 2011

A simple solid-phase synthetic approach has been exploited for the preparation of Ni-carbon sphere composites using Ni(CH3COO)2•4H2O as nickel source, and vitamin C (L-ascorbic acid) as reductant and carbon source at 500oC for 6 h. The products were characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray energy dispersive spectrometer (EDS), raman spectroscopy and microwave-absorbing measurement. The results show that the products are composed of Ni-carbon sphere particles with average diameters of 1.2 µm. Each sphere particle contains embedded Ni particles with average diameters of 83 nm. The reflection loss (RL) values of the products are lower −10 dB at 2–18 GHz, displaying broad range of microwave absorption. Their minimum RL value is about −33 dB at 4.2 GHz, which exhibit good microwave absorbing properties.
Microwave Synthesis of Nano-Titanium Carbide
Authors: Liu Ping An , Yang Qing Song , Shui An Ze , Wang Hui , Cheng Xiao Su , Zeng Ling Ke , Liu Yang
Published: December 2011

A new synthesis technology of titanium carbide with microwave is introduced in this article. Microwave synthesis technology is a fast and relatively low temperature of synthesis method. Nano-titanium carbide powders were synthesized by carbothermal reduction of titanium dioxide and carbon black with the microwave synthesis method at 1100°C-1400°C in argon gas atmosphere. Nano-TiO2powder and carbon black were used as raw materials. The TiC powders were characterized with the XRD and TEM. The experimental results show that the synthesis rate is quick, even at relatively low synthesis temperature. The average particle size of the TiC powders synthesized by the microwave synthesis technology under low temperature (<1300°C) is less than 50nm, and the average particle size augments with increasing the microwave synthesis temperature and time.
Hydrothermal Synthesis and Property of Rare Earth of Fluoride NaYF4:Er3+ Materials
Authors: Chen Zao Ming , Chen Xi Rong , Hu De Yuan
Published: December 2011

High quality NaYF4and NaYF4:Er3+materials were prepared using EDTA-assisted hydrothermal method. The effects of doping of Er3+on the shape of samples were discussed. The samples were characterized by X-ray powder diffraction (XRD), and scanning electron microscopy (SEM). XRD patterns show that the samples are hexagonal phase of NaYF4and NaYF4:Er3+with good crystallization. SEM images present that the samples of NaYF4are homogeneous nanorods with a diameter of 342 nm and a length of 1043nm，the NaYF4:Er3+(5%) sample with a diameter of180.7nm and a length of 1220nm, and NaYF4:Er3+(10%) with a diameter of 139.4nm and a length of 939.9nm.The sizes of the NaYF4and NaYF4:Er3+nanoparticles are basically consistent with that calculated from XRD peak via the Scherrer equation.
Discussion on Micro-Structure and Transport Properties of Carbon Micro-Coil
Authors: Wu Fa Yu , Wang Yi Yong , Li Wei Juan , Zhou Yan Wen , Zhang Jun Wei
Published: December 2011

The micro-structure, the thermal and electrical transport properties, and their corresponding relationship of carbon micro-coils were discussed, based on the experimental results. The disordered micro-structure and the helical conformation of carbon micro-coils were responsible for the characteristic of their transport properties.
Preparation of Nanometer Ferric Oxide Powders from Ferrous Sulfate by Improved Hydrolysis Method
Authors: Chen Xi Rong , Chen Zao Ming , Hu De Yuan
Published: December 2011

Nanometer ferric oxide (α-Fe2O3) powders were prepared by improved hydrolysis method from industrial byproduct ferrous sulfate septihydrate (FeSO4•7H2O) and industrial grade ammonium bicarbonate (NH4HCO3). The structural properties were characterized by X-ray diffraction (XRD), scanning electron microscopy(SEM), transmission electron microscopy (TEM), difference of thermodynamic analysis (DTA). The results revealed that the phase of ferric oxide powders mainly consisted of spherical α-Fe2O3. The α-Fe2O3particles were relatively uniform in size and the average size of particles is 40nm. The effects of many technical factors on growing and properties of nanometer ferric oxide particles, such as the reaction time and temperature, pH value of system, calcined temperature etc were discussed in this paper.
Controlled Synthesis of Two-Dimensional Networked Gold Nanowires and Microkites by Sodium Carboxymethyl Cellulose-Surfactant Soft Template
Authors: Wang Chun Rong , Yan Xian Zai , Yu Li Li , Zhou Huang
Published: December 2011

A novel soft template method is reported to control gold nano or microstructrues. Gold nanowires with two-dimensional (2-D) network structure were prepared by anionic polymer (sodium carboxymethyl cellulose, CMC) reduction of HAuCl4. Big gold microkites were synthesized using CMC-cationic surfactant (dodecyl trimethyl ammonium chloride, DTAC) templates. Quasi-sphericSubscript textal gold nanopartilces were obtained through CMC-anionic surfactant (sodium dodecyl sulfate, SDS) templates. Electron diffraction suggested that the 2-D networked nanowires and microkite heads were single crystalline. Ultraviolet visible (UV-vis) absorption spectrum of gold structure obtained showed that there were anisotropic structure formed in reacted solutions. It is potential method to gain preferred noble metal structures by this soft template.
Stability of the Vanadium Oxide Films Forme by Reactive Sputtering and Ion Beam Enhanced Deposition Methods
Authors: Liu Chang , Jiang Mei Ping , Li Jin Hua , Wang Sa Ke
Published: December 2011

Vanadium oxide film is a common sensing film for infrared detector and uncooled infrared imaging devices, its stability directly affects the use of the thetse infrared devices.In this paper, high and low temperature cycles fatigue tests was used to check and compare the stability of the vanadium oxide films formed by different methods.The change of the temperature coefficient of resistance(TCR) and the room temperature resistance were measured and compared for the vanadium oxide film prepared by reactive sputtering and vanadium dioxide films by Ion Beam Enhanced Deposition(IBED) method. The result indicated tungsten doped Vanadium dioxide film by IBED is the most stable and has a higher TCR.
Preparation for Nano-NiO by Electrolysis of Nickel in HOCH2CH2OH Solution
Authors: Zhu Chuan Gao , Wang Feng Wu
Published: December 2011

A method to prepare nickel oxide material which has a high purity and nano-sized particle was developed. nano NiO was synthesized by sol-gel method using nickel alkoxide as precursors. The structural characterization of the obtained materials was performed by thermal analysis TG-DTA, X-ray diffraction (XRD), Laser Raman spectra and Transmission Electron Microscopy (TEM). The characterization results indicated that NiO nano-particles (size 25–35 nm) are obtained by hydrolyzing of metal alkoxide of Ni(OCH2CH2OH)2 and possess high purity.
Synthesis of Mesoporous Nickel Phosphate with Long Hollow Nanotubes
Authors: Tan Juan , Li Xu Ying , Yang Fei , Liu Jing
Published: December 2011

Mesostructured nickel phosphate was synthesized with urea as alkali by sol-gel method. The obtained material nominated as NiPO-3 was characterized by means of XRD, ICP, FT-IR, TEM, and N2 adsorption. In contrast to mesoporous nickel phosphate NiPO-1 and NiPO-2 we reported before, NiPO-3 exhibits relatively longer nanotubes reached up to 400~600 nm. N2 adsorption shows that NiPO-3 possesses high BET surface area (345.8 m2g-1) and pore volume (0.46 cm3g-1). The catalytic performance of NiPO-3 showed that the total selectivity of epoxycyclohexane and hexadienol was as high as 83.38%.
Effect of Characteristic Size on the Effective Thermal Conductivity of Anodic Aluminum Oxide (AAO) Porous Thin Films
Authors: Huang Cai Hua , Sun Xiao Hua , Sun Yi Hua
Published: December 2011

Based on the surface morphology, a model is presented to investigate the heat transfer in anodic aluminum oxide (AAO) porous thin films. The extra thermal resistance from the micropores will inevitably cause a change in thermal properties, which can be analyzed by the Fourier law. The effect of the characteristic size on the thermal conductivity is discussed in details by means of the theory of phenomenological model of phonon scattering. Considering the effects of porosity and the distribution of micropores reflected by parameter D, the function of the effective thermal conductivity of AAO porous thin films expressed by two independent variables, εp and D. The temperature field is simulated with the effective thermal conductivity and the result demonstrates a bigger temperature rise in AAO porous thin films.
Synthesis with Microwave-Assisted Sol-Gel Method and Photocatalytic Activity of Quantum-Sized TiO2 under Solar and Ultraviolet Irradiation
Authors: Lu Shi Xiang , Dai Lian , Xu Wen Guo , Ma Cheng Xiang
Published: December 2011

Quantum-sized TiO2 had been prepared by using Ti(n-OC4H9)4 as the raw material via a microwave-assisted sol-gel method. The influence of different processing temperature and time on the size of TiO2 was researched. The TiO2 was characterized by transmission electron microscopy (TEM) and X-ray diffraction analysis (XRD). The prepared TiO2 presents anatase phase structure by TEM and XRD. The photocatalytic activity of TiO2 was evaluated by the degradation rate of methyl orange in aqueous solution. The particle size of TiO2 was about 9.10 nm when the processing temperature was 160°C and the processing time was 90 min (160°C-90min), and the photocatalytic performance was the best under this size. When the initial concentration of methyl orange was 10 mg/L and the amount of quantum-sized TiO2 was 0.6 g/L, the degradation rate of methyl orange under ultraviolet and solar irradiation at room temperature in 60 min were 40% and 86%, respectively.
Preparation of High-Purity α-Alumina by Oil-in-Water Microemulsion
Authors: Ma Jing Jing , Wu Bo Lin
Published: December 2011

The main objective of this work was to prepare high purity α-alumina powder (α-Al2O3) by mixed oil-in-water microemulsion route. In this study α-alumina was prepared by quaternary microemulsion system (water/surfactant/co-surfactant/oil-phase). OP-10, alcohol and the mixed solution of cyclohexane and aluminium isopropoxide were used as surfactant, co-surfactant and oil-phase, respectively. After drying the amorphous precursor powder, α-alumina powder is obtained by sintering at 1200°C for 3-5h. The X-ray diffraction pattern shows the presence of alumina phase with crystal structure and the slow scan with step size 0.0170°/sec of selected diffraction peaks such as (113) has been recorded and calculated by Scherer’s formula. The average crystallite size is about 40nm.
Fabrication and Performances of Titanium-Grafted Microencapsulated Phase Change Materials
Authors: Xu Meng Yi , Lin Shu Le , Gong Sheng Zhao , Yang Zhuo Ru
Published: December 2011

Nanocomposite microspheres were successfully prepared by grafting TiO2particles to microPCMs by chemical reaction method. The effects of modification of nano TiO2particles, adding time of TiO2dispersion and the amount of TiO2on the surface morphology were investigated. The results indicated that the optional method is adding the TiO2dispersion as soon as all the prepolymer was added to the reaction system, and the optional mass ratio of TiO2to microPCMS is 10wt%.
Hydrothermal Synthesis of Calcium Borate Whiskers
Authors: Song Shuang Jie , Nai Xue Ying , Li Wu , Zhu Cheng Cai , Meng Qing Fen
Published: December 2011

A type of calcium borate whiskers with highly thermal stability was synthesized by hydrothermal method at 180 °C for 2 h, using borax, calcium chloride and sodium hydroxide as raw reactants. The X-ray powder diffraction (XRD) indicated that as-prepared products were composed of monoclinic Ca2B2O5·H2O phase. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images showed calcium borate whiskers with a length of 50~100 μm and diameter 1.0 ~3.0 μm. Selected-area electron diffraction (SAED) pattern showed that the calcium borate whiskers were single crystalline structure. The adjustment of temperature of hydrothermal reaction, can lead to obvious morphology changes of products, and the possible chemical reaction and growth mechanism were proposed. Furthermore, the analysis of thermogravimetry (TG) showed the calcium borate whiskers released crystal water at 370~425 °C.
A Novel Gold Nanoparticle/Poly(AMPS-co-HEMA) Composite Hydrogel for Selective Catalysis
Authors: Wang Ke Ping , Lin Song Bai , Wang Na Na , Ke Ai Ru
Published: December 2011

A modified seed-mediated growth method was developed for in situ controllable preparation of gold nanoparticles (GNPs) within P(AMPS-co-HEMA) hydrogel networks. When the time of cycles absorbing procedure increased in mother solutions under given temperature during the processing stage, the number of GNPs was significantly increased and networks were utilized for in situ nanoparticles synthesis by reduction of glod ion absorbed. TEM images confirmed that GNPs were between 100 and 200 nm in size and distributed uniformly in gel. The network embedded GNPs also endows the composite gel with selective catalytic activity for selective catalysis in the reduction of nitro compound (2-NP, 3-NP and 4-NP). The kinetics of the reduction reaction were investigated under the same condition, the result showed the GNPs gel system was found to have an excellent catalytic activity and high conversion for 4-NP reduction among nitrophenol homologue, the nitrophenol hydrogenation rate got to 6.63 mol/g min for reducing of 4-NP compared to 3.69 mol/g min, the rate of 2-NP. It was almost zero for 3-NP implying no catalytic activity, even though they were isomeride.
Effect of Stacking Fault Energy on the Mechanical Properties of Cold-Rolling Cu and Cu-Al-Zn Alloys
Authors: Cheng Lian Ping , Liang Xiao Guang , San Xing Yuan , Gong Yu Lan , Zhu Xin Kun
Published: December 2011

Sacking fault energy (SFE) plays a significant role for metals or alloys to getting high strength and expected ductility simultaneously. Here the effect of SFE variation on mechanical properties has been studied in cold-rolling Cu and Cu-Al-Zn alloys. Tensile testing results show that the strength and ductility of the materials increase simultaneously with decreasing SFE. X-ray diffraction measurements indicate the peak broadening for the crystallite size decreasing and the lattice strain increasing with the stacking fault energy lowering . The relationship between the microstructure and mechanical properties of the materials is briefly discussed in this paper.
Long-Time Thermal Structural Stability Study on NiCr20TiAl Alloy
Authors: Yu Qiu Ying , Shen Zhi , Zhang Mai Cang , Jia Guo Qing , Xie Xi Shan
Published: December 2011

The coarsening kinetics of main strengthening phase γ′ and the growth behavior of grain boundary carbides have been investigated on NiCr20TiAl alloy aged at 550~750°C for 200~10,000h. The precipitates of NiCr20TiAl alloy at standard heat treatment condition are γ′, M7C3, M23C6 and MC. The coarsening of γ′ precipitates proceeds by Ostwald ripening controlled by volume diffusion in the alloy. Grain boundary carbides M23C6 and M7C3 increase with ageing times and temperatures. The morphologies of precipitates after long-time ageing almost remain the same as that at standard heat treatment condition except 750°C.
Uiformly-Sized, Molecularly Imprinted Polymers for Naproxen by Precipitation Polymerization
Authors: Jiang Xu Hong , Liu Zhan Mei
Published: December 2011

Uniformly-sized, molecularly imprinted polymers (MIPs) for (D)-naproxen have been prepared by a precipitation polymerization method using methacrylic acid (MAA) as a functional monomer and divinylbenzene (DVB) as a cross-linker in acetonitrile or a mixture of toluene and acetonitrile(1:3). The (D)-naproxen-imprinted MAA-co-DVB polymers were monodispersed microspheres with size in the range of 1.5 to 3.6µm. Enantioseparation of naproxen was attained using the (D)-naproxen-imprinted MAA-co-DVB polymer microspheres. When Ethylene glycol dimethacrylate(EGDMA) was used as a cross-linker, the MAA-co -EGDMA polymers were sub-microspheres with the average size of 350nm and showed very low affinity for the template (D)-naproxen . The (D)-naproxen-imprinted MAA-co-DVB polymer microspheres prepared in the mixture of toluene showed the highest molecular recognition ability and with the biggest size of 3.6µm.
Preparation and Thermal Stability of Micro/Nano Silicone Rubber Particles
Authors: Wang Fei , Wang Xin Long
Published: December 2011

The micro/nano particles of silicone rubber were prepared with α, ω-dihydroxy polyorganosiloxane, as basic polymer and crosslinking agent via emulsion polymerization method at room temperature. The structure and performance of the particles were characterized by transmission electron microscopy (TEM), FT-IR, thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The results indicated that the particles had certain ordered structure and thermal stability.
Molecular Dynamics Simulation of Nanoindentation on Diamond Crystal [100] Surface
Authors: Liu Jian , Kong Jin Xing , Lei Da Jiang , Zhang Ya Lin , Li Hai Feng , Zhao Xiao Ping
Published: December 2011

The nanoindentation of diamond crystal [100] surface is studied in this paper, by using molecular dynamics simulation method and Tersoff potential. The total number of atoms in the model is exceed to 2,000,000. The crystal structure changes and the bond formations of C atoms under pressure load are analyzed. A light load causes lattice distortion but cannot cause bond breaking or hybridization transition from sp3 to sp2. When the load is enough heavy, the energy be imposed on the workpiece will beyond the range of lattice distortion, which can cause bond break and hybridization transition from sp3 to sp2.
Dealloying Behavior of Al-Cu-Sn Ternary Alloy in an Alkaline Solution
Authors: Feng Ye Fei , Zhang Shi Chao , Xing Ya Lan , Liu Wen Bo
Published: December 2011

In this article, a new ternary Al-Cu-Sn alloy system has been exploited through chemical dealloying in a 20wt% NaOH solution for 8 hours at different temperatures. The experimental results show the dealloying temperature plays a significant role in the formation of Cu6Sn5 and the length scales of the small-sized ligament/channels in fixed delloying duration. With the increase of dealloying temperature, more new phase Cu6Sn5 emerges and the length scales of the small-sized ligament/channels increase. Additionally, the as-dealloyed samples have three-dimensional (3D) structure composed of large-sized channels (hundreds of nanometers) and small-sized channels (tens of nanometers). Both large and small-sized pores are 3D, open and bicontinuous.
Behaviors of the Zr–1.0Sn–0.39Nb–0.31Fe–0.05Cr Alloy at High Temperature
Authors: Tang Yi Yuan , Meng Jie Li , Huang Kai Lian , Liang Jian Lie
Published: December 2011

Phase transformation of the Zr-1.0Sn-0.39Nb-0.31Fe-0.05Cr alloy was investigated by high temperature X-ray diffraction (XRD). The XRD results revealed that the alloy contained two precipitates at room temperature, namely β-Nb and hexagonal Zr(Nb,Fe,Cr,)2. β-Nb was suggested to dissolve into the α-Zr matrix at the 580oC. Thin oxide film formed at the alloy’s surface was identified as mixture of the monoclinic Zr0.93O2and tetragonal ZrO2, when the temperature reached to 750oC and 850 oC. The thermal expansion coefficients of αZr in this alloy was of αa = 8.39×10-6/°C, αc = 2.48×10-6/°C.
Effect of Ferric Oxide Addition on the Performance of MgO-Al2O3 System Materials
Authors: Wang Jian Sheng , Wang Zhi Fa , Bu Jing Long , Chen Jun Xing
Published: December 2011

The MgO-Al2O3 system materials were prepared at 1600°C for 3h with magnesia powder and alumina powder as raw materials and with ferric oxide powder as additive. The effect of the ferric oxide additive on the sintering and thermal shock resistance of the composite materials was studied. The results showed that increasing the ferric oxide dosage could improve the densification of the MgO-Al2O3 system materials. In sample MAF-0, crystal phases all are spinel phase. With the ferric oxide dosage increased from 2% to 6% in MAF-2, MAF-4 and MAF-6, the MgAl2O4 (spinel) became the primary crystal phases, and less amount of sosoloid 20MgO•19Al2O3•Fe2O3. In comparison with samples MAF-0, MAF-2, MAF-6, sample MAF-4 has better structure compactness and thermal shock resistance, the optimum ferric oxide dosage was added in MgO-Al2O3 system material is equal to 4%. The MgO-Al2O3 system material is acceptable for application in cement rotary kiln linings and high temperature gas filter support.
Influence of Heat Treatment Process on Properties of Polycrystalline Alumina Fiber
Authors: Xu Jian Feng , Fu Shun De , Zhang Ke
Published: December 2011

Polycrystalline alumina fibers were prepared by sol-gel method. The influence of heating rate on average tensile strength of fibers as well as the influence of calcining temperature on average tensile strength of fibers, crystal phases form, specific surface area of fibers were studied. The results show that when the heating rate (below 600°C) is 4°C/min,the average tensile strength of fibers over 1000Mpa The fibers pulverize obviously when the heating rate＞7°C/min. The average tensile strength and the specific surface area of fibers decreased with calcining temperature rising. When the calcining temperature reaches over 1300°C, the average tensile strength of fibers decreased quickly and the specific surface area of fibers decreases slowly for the crystalline growth.
Research on the Sinterability of MgAl2O3/SiC Composites in Air Atmosphere
Authors: Cao Chun Hui , Wei Jun Cong , Huang Jian Kun , Tu Jun Bo
Published: December 2011

MgAl2O4-SiC composites were prepared by using MgAl2O4 and SiC powder as main starting materials, being pressed to cylindrical specimens of Φ30mm×30mm at 200 MPa and heated respectively at 1400°C and 1500°C for 3 hours in air atmosphere. The room temperature physical properties of sintered samples were tested according to related national standards. The phase compositions were analyzed by XRD. The microstructure of the fracture of the samples was observed by SEM. The results showed that MgAl2O4-SiC materials could sintered well in air atmosphere. The mechanism is that SiC was oxidized to form active SiO2, which reacted with MgAl2O4 to produce liquid cordierite promoting the sintering of the materials. The sinterability of MgAl2O4-SiC materials was overall improved with increasing the sintering temperature. When the content of SiC of MgAl2O4-SiC materials was 10%, the cold crushing strength and bulk density of the samples reached maximums and apparent porosity reached a minimum; the content of SiC was more than 10%, the sinterability of samples deteriorated.
Synthesis of MgAl2O4-SiC-C Refractory Powders by Using Forsterite, Alumina and Carbon Black
Authors: Duan Hong Juan , Zhu Hong Xi , Liang Ping , Yuan Wen Jie , Deng Cheng Ji
Published: December 2011

In this paper, the synthesis of MgAl2O4-SiC-C refractory composite powders by forsterite, alumina and carbon black was studied. The samples were calcined under reducing atmosphere and argon atmosphere at 1650 °C for 4 hrs respectively. The phase compositions and microstructure of the synthesized powders were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The result shows that adding excess carbon can enhance the formation of SiC. The argon atmosphere can promote the carbothermal reaction of forsterite and the growth of spinel crystal.