bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Cobalt Loading in Nitrogen-Doped Carbon on Oxygen Reduction Reaction for PEM Fuel Cells
Authors: Chen Sheng Zhou , Yang Wei , Li Liang Wei , Zou Han Bo , Lin Wei Ming
Published: July 2012

Nitrogen-doped carbon supported Co catalysts (CoNC) were synthesized via condensation reaction of pre-polymer of melamine formaldehyde resin with addition of cobalt nitrate salt, followed by carbonization in nitrogen. Rotating disk electrode technique (RDE) and scanning electron microscopy (SEM) with energy dispersive X-ray spectrometry (EDS) were used to identify the structure and oxygen reduction reaction (ORR) kinetics of the catalysts. The results show that the catalysts with 3.77 wt% Co loading yield the best ORR catalytic activity. Koutecky-Levich plots indicate ORR mechanism is governed by mixed mechanisms and the measured electron number varies between 2 and 4. SEM image shows an irregular lamellar structure of CoNC catalyst formed at high temperature, and different Co loadings in CoNC catalyst do not change its surface morphology.
Microstructure, Mechanical and Degradation Properties of Extruded Pure Mg for Biomedical Application
Authors: Li Zhi , Zhao Jiong
Published: July 2012

Magnesium is potential biodegradable implant materials due to its attractive biological property, degradability and possesses mechanical properties similar to bone. But cast magnesium has an unsatisfactory mechanical property. Microstructure, mechanical properties, and degradation properties of the extruded pure Mg have been investigated by use of optical microscope, tensile testing, and Hank's solution that simulates bodily fluids. Microstructure observation has shown that the extrusion significantly refined the grain size of the cast magnesium, which mainly contributes to the high tensile strength and good elongation. The degradation rate is shown to be significantly reduced by grain refinement produced by extrusion. The results of the present study showed that pure magnesium by extrusion treatment is a simple and promising way of enhancing the mechanical properties and corrosion resistance of pure Mg in Hanks' solution.
Design of Time-Lapse Core-Pulling Mechanism with Side Slide in Die-Casting Die
Authors: Jiang Meng , Yang Yang , Zhang Hong Feng
Published: July 2012

In the process of die-casting die design, the die castings should be usually left in the moving die in order to design ejecting mechanism conveniently when open mould. For the special structure of die castings, when lateral side core-pulling mechanism and larger wrapping force on the fixed-die core than on the moving-die core are required, the time-lapse core-pulling mechanism with side slide block can be adopted, which can make die castings left in the moving-die after open mould, and assure die castings production to do successfully. Time-lapse core-pulling mechanism with side slide block is ingenious and simple, and doesn’t increase the production cost of die casting die, and has certain reference value to the design of it.
Research on the Cutting Properties of SiC/Cu Composite
Authors: Wang Jin , Li Jian Gang , Xie Nian Suo
Published: July 2012

The cemented carbide tool and high speed steel tool are used as experimental cutting tools. The cutting properties of composite were studied by cutting lathe, tool microscope and light-section method microscope. The results show that carbide and high speed steel tool flank wear rate increase with the increasing of SiC particles size as well as the content of SiC particles. When the particles size of SiC is 40μm, composite cutting surface roughness increases with increasing of the content of SiC particles. While the particles size of SiC is 20μm, composite cutting surface roughness decreases with increasing of the content of SiC particles. In the same cutting conditions, the Carbide tolls have longer life than high-speed steel tools.
Determination of Multiple Heat Flux at the Metal-Mold Interface during Casting Solidification
Authors: Zhang Li Qiang , Wang Rong Ji
Published: July 2012

For successful modeling of the solidification process, a reliable heat flux boundary condition is required. Many research works has contributed to understand the mechanism of heat transfer and to quantify the heat flux at the metal-mold interface. However, for ease of calculation, the metal-mold heat transfer is often assumed to be uniform and no spatial variation in the air gap formation among these researches. In this paper, a two-dimensional inverse conduction model is introduced. The proposed model can be used to calculate the heat flux with spatial variation. The accuracy and stability of the model has been investigated by a typical profile of heat flux simulating practical conditions of casting solidification. Meanwhile, the effects of various calculation parameters in the inverse algorithm have been also analyzed. The analyzed results show that the proposed inverse model is a feasible and effective tool for determination of the metal-mold interface heat flux.
Mechanical Behavior of Overlap-Welded of Dissimilar Steels (Structural-Stainless) under Monotonic Load
Authors: Fuentes Andrés L. García , Bazán Pierre , Centeno Leiry , Ramos Magaly , Velázquez Del Rosario Alberto
Published: July 2012

The research shows the characterization of mechanical properties in dissimilar steel welded unions: a structural steel ASTM A537 (I) overlap welded with an austenitic stainless steel ASTM A240 (304L) through semiautomatic electrical arc welding process protected by inert gas (GMAW); Argon is used as a protecting gas and austenitic stainless steel ASTM A240 (308L) as a supplier material. Samples were tested in not welded conditions so as to characterize the materials involved in the research, and they were also tested in welded conditions, not being submitted to pre and post welding Thermal Treatment (TT). Welded-based material samples were characterized through Optical Microscopy (OM) and Scanning Electron Microscopy (SEM), an inspection of Not Destructive Test (NDT) with penetrating liquids and ultrasound was also conducted. The following mechanical tests were completed, not only on the Base Metals (BM), on the Welding Join (WJ) as well: Vickers micro hardness profile, tension, and face bending test. Results showed a proper mechanical steel behavior, welded by GMAW procedure, under monotonic, in spite of the relatively high values of microhardness in the Heat Affected Zone (HAZ), specifically near the fusion line between weld and stainless steel.
FEM Analysis of the Cracks Formation and Control in SV Plates
Authors: Liu Hui Min
Published: July 2012

To prevent the formation of the cracks in slide gate valve (SV) plate, theoretical analysis of the formation of the four types crack in it was carried out by finite element method, and its shape was improved on basis of its traditional structure. The results show that the analysis results match with the actual situations well. The new SV plate can prevent the formation of the cracks along its sliding direction effectively, and the pre-stress applying mode is simple.
Cold Bending Properties of Under-Matched Butt Joints for High Strength Steel
Authors: Wang Jia Jie , Dong Zhi Bo , Zhang Jing Qiang , Yang Jian Guo , Liu Xue Song , Fang Hong Yuan , Gang Tie
Published: July 2012

In this paper, cold bending properties of Q620-CF steel butt joints were analyzed based on the finite element method. Finite element analysis (FEA) results indicate that the flush under-matched butt joints have lower bending properties than the flush equal-matched butt joints, but under-matched butt joints with definite reinforcement shape can get greater bending force and better cold bending angles than the flush equal-matched butt joints. It shows that shape design of the reinforcement can improve the bending load-carrying capacity of under-matched joints. The reliability of the FEA has been verified by the experiment.
Design of Injection Mould with Thread Automatic Demoulding Mechanism for Focusing Handwheel
Authors: Yang Yang , Zhang Xin , Zhang Hong Feng
Published: July 2012

According to the characteristics of threaded plastics in the focusing handwheel of the light machine, a kind of new type injection mould is designed to take off thread. The mould core consists of six flaps and a guide posts, and the whorl is taken off automatically through the relative motion by guide posts and flap. The injection mould effectively avoids the interference effect in the course of taking off thread. The productivity is increased effectively, and the stable plastics quality is kept in practical application.
Analytical Model Study of Ellipse Crank Arm Final Upset Forging Force on Slab Method
Authors: Wang Dong Yan , Zhang Lian Hong
Published: July 2012

According to the structure of the crank arm, the conformal mapping method was adopted to transform the elliptical section map of it to the round. Then by the slab method an analytical model for final upsetting force of the crank arm was established, which is a derivation based on assumptions of axisymmetric plastic forming status. Finally, a simulation was implemented in case of the second crank of crankshaft 6G32. Accordance to it the accuracy of the analytical model was examined. Further more the causes of the data deviation from the model and the simulation were analyzed in this thesis.
Microstructure and Properties of High-Energy Pulsed Cold-Welded Surfacing Layers on 18Cr2Ni4WA Steel
Authors: Zhang Qing , Zhang Qing , Shen Wei , Tan Jun
Published: July 2012

The cold-welded surfacing layers have been prepared with SKD61 welding wire by high-energy pulsed cold-welding technology on 18Cr2Ni4WA steel. The microstructure of cold-welded surfacing layers was observed by Scanning Electron Microscope(SEM)and the bonding Strength and mircohardness were tested as well. The results showed that the microstructure of cold-welded surfacing layer is mainly composed of acicular martensite ; the matrix structure of composition is granular bainite;The mean cohesive strength of cold-welded surfacing layer is 826MPa;and its mean microhardness(393.5HV)is obviously higher than that of substrate, which can increase the anti-wear property of material.
Numerical Simulation of the Effect of Blowing Pressure on the Blow Molding of HDPE Oil Drum
Authors: Liu Sha Li , Peng Jiong
Published: July 2012

Abstract: The computational fluid dynamics software POLYFLOW was used to simulate the inflation stage in extrusion blow molding of an HDPE oil drum and calculate the velocity distribution of parsion, the thickness distribution and contact time after inflation. The results show that, the thickness decreases as the blowing pressure increases. The thickness at the bottom and corners of the blown drum is thinner than that at others. The velocity increases as the blowing pressure increases after pinch-off. The parison contacts with the mould earlier as the blowing pressure increases. In the region of the handle, the contact time is the shortest.
Rapid Growth of Tin Whiskers on the Surface of Sn3.8Ag0.7Cu1.0Y Alloy
Authors: Tian Jun , Hao Hu
Published: July 2012

It is known that rare-earth elements exhibit high chemical activity and adding trace amount of rare-earth Y in the solder can significantly improve the properties of solder alloy. However, adding excessive rare-earth Y in the solder will result in rapid growth of tin whiskers. The research results show that: if the YSn3 precipitates formed in the interior of Sn3.8Ag0.7Cu1.0Y were exposed to the air, YSn3 precipitates will oxidize and expand in volume, and the tremendous compressive stress produced by the surrounding solder matrix constraining the volume expansion will accelerate the growth of tin whiskers.
The Synthesis and Characterization of Ti-MCM-41 by Microwave Radiation
Authors: Zhang Juan , Zhao Di Shun , Liu Meng Shuai , Li Jun Pan
Published: July 2012

Mesoporous molecular sieve Ti-MCM-41 was synthesized by means of microwave radiation in domestic microwave oven using cetyltrimethyl ammonium bromide as template and ethyl orthosilicate, tetrabutyl titanate as raw materials, respectively. The sample is indeed Ti-MCM-41 after characterization by XRD, SEM, FT-IR and BET surface area. Compared with the reported synthesis methods, remarkable predominance of this method is that operation is simpler, crystallization time is shorter (only 40 min) and energy consumption is lower.
Effect of Microwave Treatment on the Properties of PET Fiber
Authors: Li Jing Ya , Ren Jian Xi , Cai Zhi Feng , Niu Mei , Hou Wen Sheng , Dai Jin Ming
Published: July 2012

PET fiber was preprocessed by means of microwave radiation. Different reaction parameters such as the time, the power and the Ph value of solution were optioned to study the degree of the fiber hydrolysis. The changes of mechanical performance and hygroscopicity of the fiber were analyzed, which showed that the best power of microwave radiation was the 250W, the best reaction time was 5 min, and the Ph value of solution was 9. Compared with the untreated fiber, the fracture strength of treated fiber is 1.686cN/dtex and the moisture regain is 0.58%. The morphology structure were characterized by SEM and the fracture strength were tested by filament electronic strength tester. The results showed that the surface of PET fibers became rough and the quantities of the -OH and -COOH functional groups on the surface increased after etching. Meanwhile the hygroscopicity of the treated fibers had been enhanced obviously and the fiber strength had been reduced.
Influence of Grain Size on Corrosion Resistance of a HSLA Steel
Authors: Chen Yan Tang , Zhang Kai Guang
Published: July 2012

The mechanical performance, workability, weldability and corrosion resistance of structural high strength low alloy (HSLA) steels used in offshore engineering have been generally required. The effect of grain size on the corrosion resistant performance of a C-Mn structural steel has been investigated with stress on hunting a appropriate grain size to balance mechanical properties and corrosion resistant performance. The results showed that the C-Mn steel with grain size in 10～25μm scope provided expected mechanical properties and corrosion resistance.
Preparation of TiO2/Bamboo Charcoal Photocatalysts with Sol-Gel Method
Authors: Xia Chang Bin , Liu Chun Hua , Wu Dao Xin
Published: July 2012

TiO2/bamboo charcoal complex photocatalysts has been prepared for tetra-n-butyltitanate as titanium source, bamboo carbon (BC) as the carrier with Sol-Gel method.it Characterizations were analyzed using TGA, DSC, SEM, XRD, DRS (diffuse reflective spectrum) and FT-IR spectra.
Analysis of the Stones of Thousand Hand Buddhism by the Combination of On-Site and Laboratory Techniques
Authors: Tian Xing Ling , Li Nai Sheng , Zhang Zhi Guo , Hu Yuan , Zhan Chang Fa
Published: July 2012

As world cultural heritage, Thousand Hand Buddhism in Dazu County of Chongqing City has been eroded Seriously after exposure to Wet atmospheric environment for about 800 years. In order to protect it, the reason of erosion should be found first. So the stones of Thousand Hand Buddhism have been analyzed using both on-site techniques(3D video microscopy, portable IR and so on) and laboratory techniques(SEM,AES and Ion chromatography etc.), and the limitations of all the above techniques are discussed. The on site results show that the stones are sandstones which contain montmorillonite, and the surface morphology of stones has changed significantly. The laboratory results show that many acidic inorganic anions can be found. and the content of SO42-is highest among all the inorganic anions, which indicates that the SO2 in the wet air should attend the reaction of the erosion. All the results show that air pollution in the Wet atmospheric environment should be the main reason of the erosion, and that on site techniques have the characteristic of nondestructive, while laboratory techniques can do more Quantitative analysis, only when they are combined can the stone relics be analyzed scientificly.This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.
Preparation of Nanosized RuB with Lower Ru Content Supported on Al2O3 and its Catalytic Activity
Authors: Xu Sheng Xian , Li Feng Yi
Published: July 2012

The nanosized RuB amorphous alloys with three different ruthenium contents supported on Al2O3 were prepared by means of impregnation, following the chemical reduction with KBH4 solution. The gas-phase benzene hydrogenation was used as a probe reaction to evaluate the catalytic activity of the prepared catalysts. The catalysts were characterized by BET, inductively coupled plasma (ICP), X-ray diffraction (XRD), and transmission electron micrograph (TEM). The experiment results show that the catalytic activity of the three amorphous alloy catalysts goes up first with the increasing of temperature and has a maximum at 443K; when the Ru loading amount is 0.24 %(wt.%) of the catalyst, which is very few, the conversion of benzene on RuB/Al2O3 amorphous alloy catalyst can reach to 99.50% at 443K.
Mechanism of TWIP Steel Tensile Deformation
Authors: Su Yu , Li Lin , Fu Ren Yu , Li Qian , Chen Guang
Published: July 2012

The microstructure of the TWIP steel before and after tenslie test was investigated by metallographic microscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results showed that the plastic growth of TWIP steel was mainly due to the TWIP effect induced by twining crystal. Some austenite grains had two or more twining system in the TWIP steel. Both the boundaries of twins and original austenite grain hindered the growth of twins. Its main textures included Goss{110} , Brass{110}, Copper{112} and CuT{552} and evoluted under the effect of twins and dislocation mechanism.
The Photo-Catalytic Activity of Cu2+-Doped TiO2 and Applications in the Self-Cleaning Performance of Textile Wall Fabrics
Authors: Shen Yan Qin , Wu Hai Liang
Published: July 2012

TiO2 photocatalyst and copper-doped titania (Cu/TiO2) photocatalyst were prepared and both photocatalysts were used in the self-cleaning finishing of wall fabrics. XRD showed that the nanometer materials and textile wall fabrics were a good combination. By comparing the self-cleaning effects of two kinds of photocatalysts, the results demonstrate that textile wall fabrics finished with Cu2+-doped TiO2 photocatalyst have better self-cleaning effect under visible light.
Selection of Working Fluids for Low-Temperature Power Generation Organic Rankine Cycles System
Authors: Han Zhong He , Yu Yi Da
Published: July 2012

A Rankine cycle using organic fluids as working fluids, called organic Rankine cycle (ORC), is potentially feasible in recovering low enthalpy containing heat sources. The choices of fluids should meet the requirement of environment, safety, critical pressure and critical temperature etc. Under the proposed working conditions, R600a, R245fa, R236fa, R236ea, R227ea are chosen as the working fluids of the low-temperature Rankine cycle system, then those fluids are investigated and compared from cycle efficiency, work ratio, exergy efficiency, irreversible loss. The results show that R245fa is an available and effective working fluid for low-temperature Rankine cycle.
Research on the Controlling Technic of Conclution in If Steel
Authors: Wu Yan Hui , Zhao Ding Guo , Wang Shu Huan , Li Jian Sheng
Published: July 2012

Combining with the production experience in steel making and rolling plant, the oxide inclusions of IF steel were investigated. In the operation process, the inclusions of IF steel are main Al2O3-TiN. They are granular and dispersed in the steel, and most of sizes are 1~5μm. In the inclusion center, the Al2O3 plays the role of TiN heterogeneous nucleation center. So reducing the Al2O3 inclusion is essential to stabilize the Ti content and strengthen the fixtation to C and N in steel. The quantity of Al2O3 inclusion was closely relation to the operation process. The Al2O3 inclusions can be significantly reduced by taking some measure.
Preparation of Monolithic Transparent Mesoporous Silica and Mesoporous Onion-Like Carbon
Authors: Chen Ai Bing , Zang Wen Wei , Liu Chao , Wang Yan Yan , Jia Man Ling , Li Bo , Yu Yi Feng
Published: July 2012

Large-sized, crack-free silica monoliths have been fabricated by a fast and convenient way via EISA method using P123 as soft template and 1-hexadecyl-3-methylimidazolium bromide (［C16mim］Br) as additive. The hydrogen bonds formed between ILs and the silano groups of silica gel play crucial roles in the form of the bulk, transparent silica monolith. The mesoporous structure onion-like carbon monoliths were prepared with the transparent silica monolith as template via the nanocasting technique. The mesoporous silica and carbon monoliths have been characterized by the XRD, HRTEM, N2sorption and elemental analysis. The results reveal that pore diameter of the mesoporous carbon about 3.47nm, and the specific surface area of carbon with a nitrogen content of 4.2%, can be tuned from 408.2-629.0m2/g. HRTEM shows that this carbon material with nanoonions structure.
Rheological Properties of Plastisols Based on Low-Toxicity Plasticizers
Authors: Xu Guo Min , Ji Yu Bi , Liu Yong , Yang Zhao , Tan Hong
Published: July 2012

The rheological properties of plastisols based on low-toxicity plasticizers have been evaluated using a DV-79+ pro coaxial cylinder viscometer by steady shearing. The effect of plasticizer and temperature on the shearing rate dependence of apparent viscosity, non-Newtonian index ( n ) , as well as apparent activation energy ( Ea ) was investigated. The results indicate that all the plastisols prepared in this experiment show shear thinning pseudoplastic behavior before and after aging process. The plastisols prepared by DOTP shows an obvious shear thinning behavior than that of plastisols prepared by ATBC and DINCH. The dependence of viscosity properties on temperature of plastisols accord with Arrhenius formula except DOTP-based system, and the apparent activation energy of plastisols prepared by DINCH is bigger than that of plastisols prepared by ATBC.
Preparation and Application of Pd-Based Stainless Steel Wire Mesh Monolith Catalyst
Authors: Li Yong Feng , Li Yu , Yu Qian , Yu Lin , Wu Lun Fu
Published: July 2012

The Pd-based oxidation catalysts on stainless steel wire mesh(SSWM) monolith were prepared by electroless plating method. The effect of two different acid bath (including HNO3-HF and concentrated HCl) on the surface morphology of SSWM substrate and the adhesion of palladium particles with substrate were firstly studied. Then the etched SSWM monoliths were used as support to prepare Pd/SSWM monolith catalysts by electroless plating method and their application in toluene catalytic oxidation was also studied. The results indicated that the optimal palladium loading was 0.3wt% and the calcination temperature was 600°C. And the catalyst etched by HNO3-HF showed better activity in toluene catalytic oxidation and worse adhesion of palladium particles with substrate than that etched by concentrated HCl.
Rapid Microwave Synthesis and Fluorescence of LaF3 and LaF3:Re (Re=Ce3+, Eu3+, Tb3+) Nanocrystals
Authors: Xu Xu Yao , Ma Lin , Zhou Xiao Ping
Published: July 2012

LaF3 and LaF3: Re (Re= Ce3+, Eu3+ and Tb3+) nanocrystals have been successfully synthesized by a facile and rapid microwave heating method. The structure, morphology and fluorescent properties of the as-prepared products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and photoluminescence spectroscopy (PL). XRD patterns showed that the undoped and doped LaF3 nanocrystals had hexagonal structure with good crystallinity and high purity. TEM and HRTEM images showed that the LaF3 nanocrystals have uniform sizes with mean diameter about 20 nm and are characteristic of inner cavities. The luminescence spectra of the LaF3: Re (Re= Ce3+, Eu3+ and Tb3+) nanocrystals indicated that different rare-earth ions have been successfully doped in LaF3 matrix via the microwave heating method.
Preparation and Performance of Enviromentally Friendly Chemical Cleaner
Authors: Liu Zhen Fa , Zhang Li Hui , Yan Mei Fang , He Rui
Published: July 2012

A enviromentally friendly solid chemical cleaner is made from citric acid,sulfamic acid,polyasparticacid,sulfourea and accessory ingredient.The performances of corrosion inhibition and biodegradability of cleaner are studied by the static hanging piece and shaking-bottle incubating test.The corrosion inhibition mechanism of cleaner is studied by potent iodynamic polarization and the corrosion testing piece is observed by means of SEM.The results show that the cleaner has good corrosion inhibition performance on carbon steel,stainless steel,copper and aluminum.The biodegradation rate is above 94% after 28 days.
Synthesis and Properties of a Thermo-/Light-Sensitive Hydrogel
Authors: Li Li Xia , Xing Xiao Dong , Liu Zu Liang , Fan Hai Tao , Hu Man
Published: July 2012

A newly developed water-soluble azobenzene-containing monomer, 4-(4-((4- ethoxyphenyl)diazenyl)phenoxy)-N-(2-(methacryloyloxy)ethyl)-N,N-dimethylbutan-1-aminium bromide (assigned to M), was synthesized, and then a thermo-/light-sensitive gel was prepared by copolymerization of M and N-isopropylacrylamide. The properties of the gel were subsequently investigated by DSC, UV-vis, and gravimetry. The results showed that the copolymer hydrogel had a very quickly tran-cis photoisomerization rate upon UV irradiation. The critical solution temperature (CST) of the copolymer hydrogel could be toned by the M content and U, did also of the swelling ability.
Thermal Degradation of Bending Properties of Structural Larch Wood
Authors: Zhou Hai Bin , Hu Chuan Shuang , Zhou Jian Hui
Published: July 2012

Wood is being used extensively in timber construction in China. It is important to understand its response when exposed to elevated temperatures. In fire-resistant design for timber construction, the main goal is to ensure that enough structural integrity is maintained during a fire to prevent structure collapse. To study the effect of temperature on bending strength (MOR) and stiffness (MOE) of solid clear wood from Chinese larch, a total of 108 samples with various target temperatures were tested in static bending under same temperatures to ensure the wood temperature to be sustained. The results indicated that exposure to sustained temperatures caused significant degradation of bending strength and stiffness. The degradation of chemical composition of larch wood happened after 170 °C and caused a serious drop in mechanical properties of larch wood after 225 °C. The bending strength and MOE of larch wood behaved negative linear relationship with temperatures before 100 °C.
Research on Removing of Pyrophyllite in Synthetic Diamond by the Physical Method Instead of Chemical Method
Authors: Luo Zhong Ping
Published: July 2012

As a harmful impurity, Pyrophyllite must be remove in synthetic diamond purification process. It commonly use chemical method. A trial research is made on the removing of pyrophyllite impurity in synthetic diamond by physical method. As a result, after synthetic diamond materials containing pyrophyllite are selectively interground in the ball grinding machine, the pyrophyllite is effectively broken and removed from the coarse – medium grade diamond only by physical method, but diamond quality is not affected.
Effects of Ti on Microstructure and Properties of Wear-Resistant and Heat-Resistant Steel
Authors: Deng Xiang , Gong Yong Jian
Published: July 2012

According to the working condition of the wear-resistant and heat-resistant parts, it designed the composition of the wear-resistant and heat-resistant steel. Different amount of Ti were added to wear-resistant and heat-resistant steel. The effects of Ti on microstructure, hardness and wear resistance of wear-resistant and heat-resistant steel were researched by microstructure observation, x-ray diffraction，hardness and wear resistance test. The results show that proper amount Ti combines with C to form a certain number particle TiC in the wear-resistant and heat-resistant steel. TiC is dispersively distributed in austenite matrix and improves the hardness and wear resistance of wear-resistant and heat-resistant steel greatly. It has a certain economic benefit.
Study on Optimization of Polymer Modification Repair Mortar with Metakaolin
Authors: Wang Gui Ming , Leng Zheng , Kong Yun , Su Biao , Zhang Bin
Published: July 2012

This paper deals with the compressive strength and shrinkage of polymer modification repair mortar (PMRM) with Metakaolin (MK) and Metakaolin-based composite material(MS),the microstructure of PMRM was studied by MID and SEM. The results show that the strength and shrinkage of PMRM are improved remarkably with the incorporation of 3% and 5% MK. Moreover, the PMRM with the incorporation of 5% MS exhibits a better mechanical and shrinkage performance, the tests of MID and SEM indicate that the pore structure is optimized by 5% MS.
Synthesis and Characterization of Aluminum Nitride Ceramic Coating on Aluminum Alloy by Plasma Electrolytic Oxidation in CO(NH2)2 Electrolyte
Authors: Wang Yun Long , Wang Miao , Jiang Zhao Hua
Published: July 2012

aluminum nitride ceramic coating were obtained on LY12 aluminum alloy by plasma electrolytic oxidation in CO(NH2)2 electrolyte. The microstructure of the ceramic coating including phase and elements composition, surface and cross section morphology were investigated. The properties of the ceramic coatings such as surface roughness, thickness and bonding strength were primarily studied. The results show that the ceramic coating on LY12 aluminum alloy surface was AlN coating with the thickness of 12 um. The AlN ceramic coating showed rough and porous. The average diameter of the pores was 6 um and the surface roughness was 1.5 um. The bonding strength of the coating was 18 ± 2 MPa.
Impact of Cerium on Corrosion Behavior of Zinc Coating in Cl- Environment
Authors: Zhang Jiang Hong , Zhang Ying Jie
Published: July 2012

This paper aims to study the impact of cerium on the corrosion resistance of zinc coating in 5% NaCl solution. Based on the immersing experiment, electrochemistry was used to measure the electrochemical parameters when comparing the zinc coating’s corrosion resistance with that of zinc coating with an additional cerium conversion coating. SEM and XRD were adopted to analyze the appearance and phases of corrosion products of this cerium conversion coating, and to probe the impact of cerium on the corrosion behavior of zinc coating in Cl- environment. The results showed that cerium conversion coating formed on the zinc coating effectively increased the zinc’s corrosion resistance. By contrast, models of conversion coating with lower cerium content poorly protected the substrate, resulting in easy erosion of the zinc coating in Cl- environment.
Preparation of CaTiO3 Thin Film by Sol-Gel Dipping Coating
Authors: Bao Qi Fu , Dong Wei Xia , Zhou Jian Er
Published: July 2012

Smooth and dense films of CaTiO3 were prepared on the glass substrate by a sol-gel dip coating method. Characterization of the product was carried out by different techniques such as powder X-ray diffraction (XRD), scanning electron microscope (SEM) and UV–vis optical spectroscopy. The results showed that pH and water contents had a great influence on morphology of CaTiO3 film. When water content is 0.128 mol at PH=1.56, CaTiO3 film presents an absorption in the UV region and the band gap is estimated to 3.35 ev. The results show the large potential of this material in electronic structure.
Comparison of Microstructure and Properties of Ni-Based Overlay Deposit under Longitudinal Magnetic Field and Transverse Magnetic Field
Authors: Liu Zheng Jun , Liu Duo , Liu Chang Jun
Published: July 2012

plasma arc sufacing； magnetic field style ；Ni-based alloy；microstructure and properties Abstract. The Ni60 alloy was overlaid on low carbon steel by plasma arc surfacing with Longitudinal magnetic field or transverse magnetic field. The magnetic field current and surfacing current could been changed during surfacing. After plasma arc surfacing with magnetic field, the XRD, wear loss tes, micro-hardness test were used to analyze the effect of magnetic field style on properties of overlay deposit. The acting mechanism of magnetic field style and parameters on properties and microstructure of overlay deposit was researched. The results indicate that longitudinal magnetic field and transverse magnetic field all can improve the properties of overlay deposit, but give little effectives intervention to the process parameters. The active effect of transverse magnetic field is better than longitudinal magnetic field because of transverse magnetic field can make the microstructure finer, component more uniform.
Comparison of Microstructure and Properties of Co-Based Overlay Deposit under Longitudinal Magnetic Field and Transverse Magnetic Field
Authors: Liu Zheng Jun , Liu Duo , Wu Xiao Juan
Published: July 2012

The StelliteNo6 alloy was surfaced on low carbon steel by plasma arc surfacing with LMF or TMF. The magnetic field current could been changed during surfacing. After plasma arc surfacing with magnetic field, the OM, XRD, wear loss test, micro-hardness test were used to analyze the effect of magnetic field style on microstructure and properties of overlay deposit. The acting mechanisms of magnetic field style and parameters on properties and microstructure of overlay deposit were researched. The results indicate that LMF and TMF all can improve the properties of overlay deposit. The active effect of TMF is better than LMF because of TMF can make the matrix metal γ-Co finer, second phase (CoCx、Cr7C3、Cr23C and FeNi) dispersion.
Influence of Substrate Condictions on Thermal-Shocking Property of Sm2Zr2O7/NiCoCrAlY Graded Thermal Barrier Coatings
Authors: Ji Jian Ping , Hu Ren Xi , Li Shu Hua
Published: July 2012

The effect of substrate conditions, including material type, thickness and radius on thermal shocking properties of plasma sprayed Sm2Zr2O7/NiCoCrAlY functional graded thermal barrier coatings were analyzed by ANSYS—a finite element method software. Results show that thermal stresse in coatings increase with increasing of thermal expansion coefficients of substrates. The effect of substrate thickness can be ignored when it is greater than 20mm. Thermal stresses increase with radius increasing, however, they are almost not effected when substrate radius is over 18mm.
A Study of Surface Hardness Affecting in Electrical Discharge Machining on AISI P20 Plastic Mould Steel
Authors: Janmanee Pichai , Jamkamon Kamonpong , Kanchanasangtong Teerayut , Muttamara Apiwat
Published: July 2012

This article aims to show the effects of the EDM process that influences the surface hardness by comparing the hardness values before and after the spark on the plastic mould steel AISI P20. Divided by the heat treatment, there were three different hardness levels: 1) the plastic mould steel AISI P20 through the process of quenching with the hardness value in the range of 690-710 HV; 2) the steel through the process of quenching and then annealing with the hardness value in the range of 470-490 HV; and 3) the non-heat treatment steel (raw material) with the hardness value in the range of 300-320 HV. The condition of EDM spark on the surface workpiece was 3 mm of depth and 10 mm of diameter copper electrode. The experiment was carried out under the cover of hydrocarbon, using dielectric cooling, and removing debris by the side flushing through the 6 mm of diameter pipe with the flow rate of 15 liters per minute. The experiment parameters included on-time duty factor variable, off-time duty factor variable, and current. Based on the experiment, it was found that when the duty factor increased, the hardened workpiece showed the less surface hardness value. At the same time, the annealed, and the non-heat treatment workpieces showed that the hardness values were proportional to the duty factor and the current of the EDM process.
Preparation and Characterization of Nickel Oxide-Based Superhydrophobic Surface
Authors: Yuan Zhi Qing , Hao Xi Hai , Bin Ji Ping , Wang Xian , Chen Hong
Published: July 2012

A superhydrophobic nickel oxide (NiO) surface with hierarchical micro- and nanostructures was obtained by a novel and facile method. The water contact angle and sliding angle of the superhydrophobic NiO surface were 156±1.9º and 3º, respectively. The superhydrophobic NiO surface made the substrate float on the water surface and showed high buoyancy. Execept for pure water, the superhydrophobicity of the superhydrophobic NiO surface remained unchanged when contacting with salt aqueous solutions. After being stored in ambient environment for 8 months, the superhydrophobic property remained constant, and no contamination was observed on the superhydrophobic NiO surface.
The Interface Properties of La2O3/GaAs System by Surface Passivation
Authors: Jia Ting Ting , Cheng Xing Hong , Cao Duo , Xu Da Wei , Zhang You Wei , Wang Zhong Jian , Xia Chao , Yu Yue Hui
Published: July 2012

In this work, La2O3 gate dielectric film was deposited by plasma enhanced atomic layer deposition. we investigate the effect of surface preparation of GaAs substrate, for example, native oxide, S-passivation, and NH3 plasma in situ treatment. The interfacial reaction mechanisms of La2O3 on GaAs is studied by means of X-ray photoelectron spectroscopy(XPS), high-resolution transmission electron microscopy(HRTEM) and atomic force microscope (AFM). As-O bonding is found to get effectively suppressed in the sample GaAs structures with both S-passivation and NH3 plasma surface treatments.
Research on High-Temperature Volatilization Characteristics of V2O5 during Direct Alloying of Smelting Vanadium Steel
Authors: Wang Wei Xiang , Xue Zheng Liang , Song Sheng Qiang , Li Ping , Chen Zhi Chao , Liu Rui Ning , Wang Gong Liang
Published: July 2012

This paper mainly researches the volatile phenomenon of V2O5 at high-temperature and the appropriate additions to depress volatilization of V2O5 effectively during direct alloying with V2O5 to smelting vanadium steel. It shows that the volatilization loss of V2O5 is 4.34% when V2O5 is heated to 1600°C for 10 minutes. The reductant ferrosilicon and additives CaO can depress the volatilization of V2O5 effectively. The volatilization loss of V2O5 decreases to 1.55% at 1600°C when the mass ratio of ferrosilicon to V2O5 is 1:1. CaO can react with V2O5 to form calcium vanadate to decrease the activity of V2O5. The volatilization loss of V2O5 decreases to 1.82% with adding 48.0% CaO in the V2O5–CaO system at 1600°C. The volatilization loss of V2O5 with adding more than 30% CaO can decrease to 0.48% when keeping the mass ratio of ferrosilicon to V2O5 is 1:1.
Fabrication and Characterization of a Superhydrophobic Low-Density Polyethylene Film
Authors: Wu Jun Liang , Zhang Hui Ping , Wang Xu Nan
Published: July 2012

A superhydrophobic LDPE film was obtained by a simple method in atmosphere without addition of low-surface-energy materials. The water contact angle of the superhydrophobic LDPE film are 155±1.9º. SEM shows that compared with common smooth LDPE film, a porous structure was obviously observed on the superhydrophobic LDPE film. Such a special surface microstructure may result in the superhydrophobic property. The effect of drying temperature and concentration on water contact angle were studied.
Effects of Relative High Density Preparation of Interfacial Coated Pb(Zr0.52Ti0.48)O3 on CaCu3Ti4O12 with Short Sintering Time on its Dielectric Properties
Authors: Ali Rajabtabar Darvishi , Li Wei Li , Ommeaymen Sheikhnejad Bishe , Wang Li Dong , Liu Zhe , Fei Wei Dong
Published: July 2012

Pb(Zr0.52Ti0.48)O3was coated on the surface of CaCu3Ti4O12particles that prepared using sol-gel method. Then the composite particles were sintered into composite ceramics using cold press with the two different pressures and pressing time to achieve sufficient higher relative density after sintering. Afterward, the composite particles were sintered into composite ceramics with various sintering time at the same temperature to reach smaller grain size and higher relative density. The results show that the ceramics are composed of Pb(Zr0.52Ti0.48)O3and CaCu3Ti4O12phases, and Pb(Zr0.52Ti0.48)O3phase is mainly exist at the grain boundary even the composite particles sintered for 2h before pellet making. The results exhibit when density of CaCu3Ti4O12/Pb(Zr0.52Ti0.48)O3composite ceramic is kept in higher level using this simple technology, not only The dissipation loss in these giant-dielectric constant materials was reduced to a considerable level of practical applications but also dielectric constant enhance to very high level in the large frequency range. The results show that the improvement of the dielectric loss and dielectric constant enhancing mainly comes from the increase in the density of the CaCu3Ti4O12/Pb(Zr0.52Ti0.48)O3composite ceramics using suitable pressure in cold press, suitable short sintering time that lead to smaller grain size and sufficient grain boundary.
Development of Dielectric Elastomer Actuators - Part I: Performance of Polyurethane Film Actuators with Dangling Chains and Network Structures
Authors: Fukuda Takeshi , Luo Zhi Wei , Ito Aya
Published: July 2012

Dielectric elastomer actuators with enhanced flexibility were prepared by thermosetting polyurethane (TSU) consisting of polypropylene glycol (PPG) as an active hydrogen component and toluene diisocyanate (TDI) as an isocyanate component. The improvement was achieved by less hard segment content, i.e. less isocyanate index, the synthesized film actuators were compared with the actuator softened using a plasticizer. It was found that the film actuators prepared by this method had significant advantages in actuation under a lower electric field as well as the increase of electrical breakdown strength and of strain. Furthermore, the mechanically-stretched effect of the films was also evaluated. It turned out that prestrain up to 200% was effective in the increase of electrical breakdown strength while maintaining the actuation under a lower electric field. However, prestrain over 200% caused a decrease in actuation under a lower electric field.
Study on Corrosion Resistant Properties of Nano-SiO2 Modified Epoxy Coating
Authors: Wang Xiao Hong , Gao Wei , Huang Beng Sheng , Yang Mei , Shi Yi Jun
Published: July 2012

Nano-SiO2 which surface was modified by silane coupling agent was used to modify the epoxy coatings which was prepared by the method of chemical modification and physical dispersion using the modified nano-SiO2 and epoxy. The molecular structure and dispersity of the modified nano-SiO2 were studied by Fourier transform spectra(FT-IR) and scanning electron microcopy(SEM). The effect of nano-SiO2 on corrosion resistance of epoxy coating was studied by electrochemical impedance spectroscopy(EIS). The results show that the modified nano-SiO2 contained the Si-OH characteristic functional group which can promoted the nano-SiO2 grafted with epoxy and had a good dispersion; Compared to epoxy coatings, wear rate of the modified epoxy coating reduced about 20% and the impedance value of the modified epoxy coating using the method of soak in 3.5% solution of NaCl for 240h, improved by 5 orders of magnitude.
Failure Analysis of T91 Finishing Superheater Tube Bursting for Improper Initial Microstructure and their Life Evaluation
Authors: Ouyang Jie , Xu Xue Xia , Feng Yan Ting , Niu Xiao Guang , Yan Guang Zong , Zheng Xiang Feng , Ke Hao , Sun Tao
Published: July 2012

The failure analysis was performed for T91 finishing superheater bursting tube. It is concluded that improper initial microstructure resulted from non-standard heat treatment contributes to poor creep properties at high temperature and subsequent tube bursting. In addition, life evaluation was carried out on the basis of creep-rupture test result of experimental steel with similar improper microstructure. It is in accordance with the practical condition and provides significant guidance for safety and operation supervision.
Influence of Al Concentration on Performance of Cu (In,Al)Se2 (CIAS) Films
Authors: Zhou Li Mei , Wu Su Mei , Yu Jin Ping
Published: July 2012

Cu(In,Al)Se2 (CIAS) thin films with different Al contents were prepared by dc magnetron sputtering method and selenization process. At first, CuInAl (CIA) precursor films were deposited by sputtering from copper target and indium-aluminum composite targets, then followed by selenization process. The morphology, microstructure, optical and electrical properties were investigated by scanning electron microscopy, energy dispersive analysis, X-ray diffraction, four probes method and optical transmission, respectively. Variation of structural, optical and electrical properties of CIAS films with different Al contents was studied. The results show that Al content has an effect on the morphology and grain distribution. All the CIAS films maintain chalcopyrite structure with preferred orientation along (112) direction. The electrical studies show that resistivity of the films increases when the Al content increases. The optical studies reveal that the films have high absorbance and the energy band gap calculated from transmission spectra are at the rang of 1.60-1.95 eV.
The Effect of Additives (NH4Cl) to Elimination of the Iron Dissolved in Flux Solution of Hot Dip Galvanizing Process
Authors: Moon Kyung Man , Oh Min Seok , Park Dong Hyun , Lee Myung Hoon
Published: July 2012

Hot dip galvanizing is being widely used to the numerous constructional steels such as a guard rail of high way, various types of structural steel for manufacturing ship and for some other fields etc.. Recently, the cost of zinc is getting higher and higher, thus, a proper manufacturing process should be developed possibly to reduce the cost of production. one of hot dip galvanizing process, that is, flux solution immersion process is very important to control more effective coating. However, flux solution is deteriorated with increasing its using time because dissolved iron from structural steel due to continuous flux treatment was increasingly increased, which is resulted in coating badness and increment of dross. In this study, the effect of additives to elimination of iron dissolved in flux solution was investigated with four types of inner solution, that is, solution of inner barrel was filled with seawater, NaOH, thiourea, including parameters of amounts of NH4Cl(5,10,15 and 20g) and electrolysis experiment was carried out with applied current density at 20mA/cm2. For the best elimination effect of iron from flux solution, it is considered that inner barrel with separator should be filled with inner solution different from original flux solution which is involved in iron ion, and the inner solution should be composed with seawater added with additives such as NH4Cl(10g), NaOH(0.2 g) and thiourea(0.5g) when the applied current density by electrolysis method is 20mA/cm2.
Effect of Rolling Process on Microstructure and Texture of Cold Rolled Ti-6Al-4V Seamless Tubes
Authors: Jin Yun Xue , Li Kai Yue , Chen Hong Mei , Xiang Hong Fu
Published: July 2012

In this paper, initial Ti-6Al-4V seamless tube was prepared and cold rolled to a final size of 32*2, and the microstructure and mechanical properties development was investigated, and the (0002) and (10 -10) texture was measured on XRD, pole figure calculated by Microsoft of Labotex. Pass between annealing was taken for stress-relieving, heat-treatment parameter was 800°C-1hr, furnace cooling to 500°C and then air cooling to room temperature. The results show that rolling process result in effective grain refinement and mechanical properties improvement after several rolling passes. The increase number of rolling pass improves strength but reduce the elongation, annealing improve elongation, reduce strength. A trend of texture reorientation was found in this paper also, textures of materials rolled by deformation rate were compared, different deformation rate effect texture evolution has been proved.