bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Investigation Properties on Resistance of Slag Cement Concrete to Sulfate Attack
Authors: Wang Jun , Zhang Zi Jian
Published: February 2011

The water-cement ratio and cement content are key factors which reflect the anti-penetration of the concrete. To study the slag cement concrete against sulfate attack, make two types of the slag cement concrete test blocks of which one type has the same concrete content and different water-cement ratio, while the other type has the same water-cement ratio and different concrete contents; then test the concrete test blocks on compressive strength, folding strength and weight changing after dipping them into sulfate solution and drying them for thirty and sixty times .At the same time non-damage ultrasonic test was carried out. The results show the durability of the slag cement concrete is improved with the decrease of water-cement ratio; in concrete design, there is optimum cement content which theslagcement concrete has the best resistance sulfate erosion.
Preparation of Potato Starch Graft Copolymer and its Application in Functional Coatings
Authors: Jiang Meng Lan , Guo Jun Feng , Wang Rong Min , Zhu Yong Feng , Wang Xiao Wen , He Yu Feng
Published: February 2011

A new kind of self-cross-linked potato starch graft copolymer (PoSt-g-P) was prepared successfully by emulsifier-free emulsion polymerization, in which methyl methacrylate (MMA), acrylic acid (AA) and butyl acrylate (BA) were used as main monomers, and diacetone acrylamide (DAAM) as functionality monomers. The keto-carbonyl group in the potato starch graft copolymer /DAAM could react with adipic dihydrazide (ADH) at ambient temperature to form cross-linked thin film. The film properties of emulsion were measured, which showed excellent properties in hardness, gloss and water resistance. The humidity-sensitive coatings (PoSt-g-P-C) were prepared by the self-cross-linked PoSt-g-P, pigments and fillers. Adipic dihydrazide was used as a cross linking agent and assistant. Its humidity controlling properties were also measured and shown high activity in increasing humidity and dehumidify.
Research on Moisture Porosity Test of Explosive Lining Materials after Long-Term Water Immersion
Authors: Wang Hai Liang , Meng Li Zhen , Cui Zhuo , Li Shao Xian
Published: February 2011

This paper measures moisture porosity of explosive lining test pieces after long-term water immersion, so are the test pieces in standard curing condition and in equal curing condition. We have analyzed the measured moisture porosity data of three kinds of test pieces after long-term water immersion. The results indicate that the moisture porosity of explosive lining test pieces is higher than that in standard curing condition and in equal curing condition.
Effect of Gypsum on Strength Development of Steam-Cured Concrete
Authors: He Zhi Min , Shen Xiao Ju , Liu Jun Zhe
Published: February 2011

The use of fly ashes for cement-replacement purposes, especially in high volumes, decreases rate of early strength development of the steam curing concrete. To resolve it, this paper developed a new steam-cured concrete incorporating fly ash and a chemical activator (gypsum). Experiments were conducted to investigate the mechanical properties at early and later ages of steam and standard curing concretes. The corresponding mechanism was also discussed by testing the microstructure of concretes. Results indicate that the demoulding compressive strength of steam curing concrete with 4% gypsum dosage can meet production requirements, and compressive strength of this concrete at later ages increase well. Compared with that of ordinary pure cement steam-cured concrete, concrete with 4% gypsum has a higher compressive strength gain rate. At an early age, addition of the gypsum can distinctly accelerate the extent of hydration of the steam curing fly ash cement systems, and thus the microstructure of concrete becomes denser. However, in standard curing condtion, the effect of gypsum is not distinct.
Synthesis and Dielectric Properties of Ba(Ti,Y)O3 Solid Solutions to Ba3Ti2YO8.5-BaTiO3 Composites
Authors: Huang Min , Wang Yun Wu
Published: February 2011

Ceramic samples with the nominal composition (1-x) BaTiO3 + x Ba3Ti2YO8.5 (x = 0 - 0.4) were prepared by the solid-state reaction method. The X-ray diffraction (XRD) analysis and the lattice parameters determination indicate that the samples with x≤ 0.16 exhibit a single phase cubic perovskite structure. When x > 0.16, the system is of biphasic composites, which consist of Ba(Ti0.911Y0.089)O3 and Ba3Ti2YO8.5. The microstructure observation by Scanning Electron Microscopy (SEM) supports the XRD result. For the biphasic composites, the dielectric constant follows the Lichtenecker relation in a wide temperature range.
The Status and Development of New-Type Wall Material
Authors: Jiang Deng Ling , Zhao Jing , Ni Guo Wei
Published: February 2011

As is known to us, producing tradition wall materials will consume lots of energy and spoil the environment. Therefore, new-type wall has aroused great concern among people in construction, which is green, insulating and energy-saving and so on. External insulation, promoted as an energy-saving technology in building insulation, has three more mature technologies. This paper also introduces polyurethane insulation material, as the third generation of energy-saving wall materials, has a very good application prospect in scientific research. Finally, in the last of the paper, relative countermeasures and suggestions are made to improve the status and development of new-type wall materials, for instance: we should make the most of industrial waste, make deep research in new composite wall systems and wall materials; take some effective measures to accelerate the application of new wall materials and so on.
Calculation of Flexural Capacity of SRC Beams Strengthened with CFRP
Authors: Wang Xiao Chu , Liu Xiao Xing , Zhou Le , Liu Hong Tao , Yang Min
Published: February 2011

A design idea has been brought forward about SRC beams strengthened with CFRP, in order to solve flexural capacity shortage and need strengthening engineering problems. By analyzing loading process, failure mode and loading mechanism, flexural capacity was calculated by superposition method. According to different failure modes and neutral axis’ location in the steel, the computed formula of flexural capacity about SRC beams strengthened with CFRP was proposed, and it provided references for design of SRC beams strengthened with CFRP.
Shear Lag in Thin-Walled Box Girder with Variable Section
Authors: Zhang Yu Hong , Yang Zi Jiang , Liu Shi Zhong
Published: February 2011

In this paper, a equivalent-section method of analyzing shear lag effects in box girders is presented. The effect of two major parameters on shear lag is investigated for cantilever and continuous box girders with variable section under two kinds of loads. It is shown that the span-width ratio, in addition to the flange stiffness to total stiffness ratio, has a significant influence on the shear lag. Finally, conclusions are drawn with regard to further study and research.
Recent Developments for Isochronal Transformation Kinetics Model and their Applications
Authors: Liu Yong Chang , Zhang Li Fang , Yang Xu , Wang Dong Jiang
Published: February 2011

Analytical model for isochronal phase transformation kinetics attracts much attention for its advantages and importance. Adopting an effective treatment for the so-called temperature integral, an analytical model for isochronal transformation kinetics has been developed by considering various nucleation and growth modes. After applying to the analysis of the austenite-ferrite phase transformation recorded by the high-resolution dilatometric measurements, it is recognized that the developed analytical phase transformation model could be adopted effectively to determine the nucleation and/or growth mechanism prevailing during the isochronal phase transformation processes.
The Kinetics of the Austenite-Ferrite Phase Transformation of Fe-4Cr Alloy during Continuous Cooling
Authors: Zhang Li Fang , Zhang Dan Tian , Yan Ze Sheng , Liu Yong Chang
Published: February 2011

The massive transformation, austenite (γ) → ferrite (α), in Fe-4Cr alloy subjected to cooling from the high-temperature austenite down to room temperature at cooling rates of 75, 150, 330 K min-1 were experimentally investigated by means of high-resolution differential dilatometry. It is found that the onset transformation temperature and the overall transformation time decrease with increasing the cooling rate applied. Furthermore, by fitting the calculated transformed fraction according to developed phase-transformation model to the experimental data obtained by differential dilatometry, the kinetic parameters are obtained which show the activation energy for growth and the activation energy for nucleation are considerably different, this may be due to considerably different interfacial structure with the matrix for minute embryos and for the much larger growing particles.
Simulation of Microstructure and Grain Size in Welding Heat Affected Zone Using Monte Carlo Method
Authors: Zhang Shi Xing , Cai Gang Yi
Published: February 2011

In this paper, modeling, procedure and algorithm using Monte Carlo (MC) technology were investigated respectively to simulate grain size and microstructure . First, two different kinetic model were defined by both experimental and statistics method. Then the procedure and algorithm were worked out based on MC technology. Thirdly, the grain growth process in HAZ was simulated, which has great influence on grain growth in HAZ. The result of the simulation demonstrates the grain growth process dynamically. Good agreement between MC simulation results and the experimental results was obtained which can provide a reliable evidence for evaluating the welding craft and the weldability.
Effects of Erbium Addition on the Corrosion Resistance and Microstructure of AZ91 Magnesium Alloy
Authors: Wang Zhong Jun , Xu Yang , Zhu Jing
Published: February 2011

The microstructures and corrosion resistance of AZ91 and AZ91+0.5 wt.% erbium (Er) magnesium alloys were studied, respectively. The results show that the Er addition in scrap AZ91 magnesium alloy can improve the corrosion resistance, markedly. The discontinuous precipitation phase (DPP) for Mg17Al12 was retarded and the amount of DPP was decreased by 41% due to the formation of Al8ErMn4 phase during solidification. The amount of continuous precipitation phase (CPP) in grains was decreased by 8% because of the formation of Al7ErMn5 phase during solidification.
Flow Stress Behaviour of TWIP Steel during the Hot Compression Deformation
Authors: Liu Qiang , Li De Jun , Shangguan Feng Shou , Feng Yao Rong , Tong Ke
Published: February 2011

The hot deformation behavior of Fe-25Mn-3Si-3Al TWIP steel were investigated by isothermal single-pass compression on Gleeble-3500 thermal simulator at the temperature range of 900°C to 1100°C and the strain rate range of 0.01s-1 to 1s-1. The results showed that the true stress-strain curves of Fe-25Mn-3Si-3Al steel had a typical feature which often appears during the hot deformation process of metals and alloys with high stacking fault energies. In true stress-strain curves, No obvious flow stress peak was observed. With the increase of strain, flow stress reaches the saturation value, indicating that the hot deformations of these conditions are dynamic recovery. The hot compression deformation of Fe-25Mn-3Si-3Al steel can be represented by Arrhenius model. The constitutive equation of Fe-25Mn-3Si-3Al steel under hot compression deformation is calculated by a linear regression analysis. The activation energy for hot deformation of the experimental steel is 422.51kJ/mol.
Discussion on Relationship between Viscosities of Molten Zr-Cu Based Alloys and their Glass Forming Ability
Authors: Wang Jing Song , Cao Li Jun , Wang Jing Hua , Sun Hao Yan , Huang Shu You , Xue Qing Guo
Published: February 2011

The dynamic viscosities of molten Zr55Ni5Al10Cu30 and Zr50Cu50 alloys were measured by using rotating cylinder method under non-vacuum condition. According to the lnη~1/T curves, discontinuous changes were found and the activation energy was calculated. The activation energy of molten Zr55Ni5Al10Cu30 alloy is obviously larger than that of molten Zr50Cu50 alloy. Amorphous sample of Zr55Ni5Al10Cu30 with 3mm diameter was prepared successfully under non-vacuum condition, but there are crystallization phases in Zr50Cu50 amorphous sample with 2mm diameter. The relationship between viscosities of molten Zr-Cu based alloys and their glass forming ability (GFA) was discussed, and viscosities of molten Zr-Cu based alloys play an important role on their GFA.
Effect of High Pressure Heat Treatment on Microstructure and Corrosion Resistance of Brass
Authors: Liu Yu Wen , Liu Lin , Zhang Wei , Liu Jian Hua , Peng Gui Rong , Zhang Rui Jun
Published: February 2011

Effects of high pressure heat treatment on the microstructure refinement and corrosion resistance of brass were studied by means of metallographic observation, SEM/EDX, profilometer and CH1660A electrochemical instrument. Brass were heated from 23°C to 700°C and kept at 700°C for 10 minutes under high pressure of 1GPa, 3GPa, 4GPa and 6GPa, respectively. The results show that high pressure heat treatment has great influence not only on the microstructure refinement of the alloy but also on its corrosion resistance in HCl solution. Under 3GPa, the refined microstructure can be found and the corrosion resistance of the alloy changes into much worse. However, under a higher pressure of 6GPa, the corrosion resistance increases and the microstructure refining effect is not obvious. All the findings of this work were elucidated in terms of the change in the formation and growing of the crystal under a high pressure heat treatment condition.
Microstructure and Properties of Cu-17Fe Alloy Aged Treatment in High Magnetic Field
Authors: Liu Ke Ming , Lu De Ping , Zhou Hai Tao , Wen Sheng Fa , Wei Shi Yong , Hu Qiang , Wan Zhen Zhen
Published: February 2011

Aging treatment of Cu-17Fe alloy was investigated by a vacuum heat treating furnace in high magnetic furnace. The microstructures were documented using scanning electron microscopy (SEM). The solid solubility of Fe in Cu matrix was analysed by energy spectrometer (EDS). The mechanical properties were measured with a Vickers hardness tester. The electrical conductivity was measured with a micro-ohmmeter. The results showed that high magnetic field can promote spheroidization of the Fe dendrites, the spheroidization intensifies and the solid solubility decreases with the increasing magnetic induction intensity of the high magnetic field exerted to the alloy, the solid solubility of Fe is minimum when the magnetic induction intensity is 10T at 500°C during precipitation. And Cu-17Fe alloy has a good strength/conductivity combination of 110Hv/63%IACS after aging treatment of 10T at 500°C for 1h.
Analysis of the Valence Electron Structures of the Strengthening Phases Al8Fe4Ce and Al4Ce in Al-Fe-Ce Alloy
Authors: Qu Hua , Liu Wei Dong , Liu Yu Ying
Published: February 2011

Based on the empirical electron theory of solids and molecules (EET), the valence electron structures (VESs) of the strengthening phases Al8Fe4Ce and Al4Ce in Al-Fe-Ce alloy were calculated, then the relationships between the VESs and strengthening, stability of the alloy and grain refining were analyzed. The results show that the distribution of the bond network of Al8Fe4Ce is uniform, the third and the fourth bonds in the bond network of Al4Ce is the weakest segment of the whole bond network structure, and the strongest bond in the bond network of Al8Fe4Ce and Al4Ce is stronger than that of the matrix of the alloy. The VES of Al8Fe4Ce is favourable to stability of the alloy. During solidifying of the alloy, because the bonds formed by Ce atom and its adjacent atoms are all strong, that hinders Al atoms adjacent to Ce atom to involve in the growth of other grains and at the same time hinders the growth of the Ce atom group, so the structure of the alloy can be refined.
The Influence of Thermomechanical Treatment on the Microstructure and Properties of a Wrought Al-Mg-Si Alloy
Authors: Man Jin , Yang Li Li , Xia Chao Feng , Shao Guang Jie , Jin Man
Published: February 2011

. To investigate the effects of thermomechanical treatments (TMT) on the microstructure and properties of Al-Mg-Si alloy, the cold deformation on the ageing precipitation of a solution-treated Al-Mg-Si alloy was studied. The results shows that the time of reaching the peak hardness is shortened with the increasing deformation and an obvious increasing in the peak hardness and tensile strength are occured with higher amount of deformations. The microstructures of peak hardness reveals that the average size of the precipitates becomes smaller in size and greater in number in the alloy with 50% deformations. The study is also carried out to investigate the changes in resistivity of alloys during the ageing time in the alloy with and without 50% deformation. It was found that there are rapidly increasing in resistivity followed by decreasing with the onset of ageing time in both cases. However, the extent of increasing and decreasing in resistivity is much stronger in the alloy with 50% deformation. These results were discussed according to the effects of cold deformation on the dislocations and precipitates in the Al-Mg-Si alloy.
Recrystallisation Behaviour of Cu-20Ni-5Sn Alloy
Authors: Liu Rui Qing , Peng Lijun , Yang Jian Sheng
Published: February 2011

Investigate effects of annealing temperature and holding time on the recrystallization temperature, hardness, microstructure and average grain size of Cu-20Ni-5Sn alloy by hardness tester, microscope and XRD. Research the kinetic mechanism of grain growth of recrystallization of Cu-20Ni-5Sn alloy. The research result shows that the recrystallization temperature declines with the increase of cold-deformation. The recrystallization temperature is at about 500°C ~650°C respectively for 50% and 60% total cold deformation, and is about 470°C ~620°C respectively for 70% and 85% total deformation. The grains grow up with the increase of annealing temperature and holding time.
Displacement Based Seismic Design Method of RC Frame with Friction Dampers
Authors: Fan Chang Lin , Ji Hui
Published: February 2011

Displacement based seismic design of RC frame with friction damper is proposed in this paper based on the displacement shape of RC frame. and multi-degree-of-freedom system is transformed into an effective single-degree-of-freedom system. Based on equivalent linearization equivalent period is determined by using the elasto-plastic displacement response spectra, and then the structural members are designed. At the same time, target deformability of the frame and friction damper device is obtained by decomposing the structural storey drift. And the expected deformability of the structure can be guaranteed by appropriate the friction energy dissipation brace. This method could effectively control the seismic performance of the structure in earthquakes.
Effect of Ca on Microstructure and Properties of Mg-Al-Si Alloys
Authors: Xu Chun Xiang , Ju Hui , Zhou Yang
Published: February 2011

Effect of Ca addition on the morphology modification in Mg-7Al-0.8Zn-0.2Mn-1Si (AS71) alloys has been investigated using X-ray diffraction (XRD), optical microscopy (OM), and scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and various testing machines. The results show that when adding 0.1 wt% Ca, a small fraction of Mg2Si change from Chinese script type to polygonal type; with the Ca addition up to 0.3 wt%, edges and angles of polygonal type Mg2Si phase are changed; further increase in Ca addition, the morphology of Mg2Si is changed to strip-like or spot-like one. Meanwhile, the addition of Ca results in the morphology of β- Mg17Al12 phase changing from discontinuous net-like to dispersive island-like. Ca exists as solid-soluting atomic in the matrix with small Ca addition while in the form of CaSi2 with large Ca addition. Optimal mechanical properties can be achieved when Ca addition is 0.3 wt%.
Meshless Method with Radial Basis Functions for Hamilton Canonical Equation
Authors: Li Ding He , Dou Chen , Xu Jian Xin
Published: February 2011

Meshless element of Hamilton canonical equation was established in this paper by combining the modified Hellinger-Reissner variational principle for elastic material and radial point interpolation functions. Using Multiquadric (MQ), Gaussian (EXP) and thin plane spine (TPS), the astringency of meshless methods and the effects of the dimensionless shape parameters on the maximum displacement were investigated by the numerical examples of the single or the cross-lay laminated plates. And all of the numerical results of displacement w were compared with that of MSC. Nastran This study introduced the advantages of meshless finite element method into semi-analytic solution of Hamilton canonical equation, and a new semi-analytic method was presented for Hamilton canonical equation.
Preparation and Characterisation of Konjac Glucomannan (KGM)/SiO2 Nanoparticles Blend Film
Authors: Wang Chao , Xie Bi Jun , Li Bin
Published: February 2011

A novel nanocomposite films was prepared by dispersing SiO2 nanoparticles in aqueous konjac glucomanan (KGM) solution. The structure and miscibility of the nanocomposite materials were determined finely by viscosimetry, Fourier transformed infrared spectra (FTIR), micropolariscope (POM), scanning electron microscopy (SEM) and ultraviolet-visible spectrophotometer (UV-Vis). The results indicated that there was a strong interaction between KGM and SiO2 in ethanolamine. The miscibility and ultraviolet-absorption properties of KGM/SiO2 nanoparticles blend film were improved by ball milling treatment. Moreover, the ultraviolet absorption and tensile strength of the nanocomposite films rapidly increase with the increase of SiO2, while breaking elongation of the nanocomposite films slightly decreased.
Thermodynamics on Formation of Condensed Phases during CVD Si3N4 Process with Sicl4-NH3-H2 Precursors
Authors: Deng Juan Li , Cheng Lai Fei , Hong Zhi Liang , Su Ke He
Published: February 2011

Formation conditions of the condensed phases (Si3N4and Si) in CVD process of SiCl4-NH3-H2precursors have been investigated in detail with thermodynamic analyses by using the FactSage code and its embedded database (44 species being involved). The productions have been examined at different SiCl4/(SiCl4+NH3) ratios, H2/(SiCl4+NH3) ratios, temperatures and pressures. The results showed that the condensed phase composition was quite sensitive to the ratios and temperature whereas it was insensitive to pressure. The ideal conditions for the deposition of Si3N4were listed as followed: the ratio of SiCl4/(SiCl4+NH3) and H2/(SiCl4+NH3) was 0.44 and in the scope of 100.6-105.2, respectively. Temperature ranged from 1200 to 1300 K with lower pressure. Si was formed in the H2/(SiCl4+NH3) ratio of 103~105and SiCl4/(SiCl4+NH3) ratio of 0.44-1.0. The formation of single-phase Si3N4or Si would be easily controlled by changing the ratios of SiCl4/(SiCl4+NH3) and H2/(ZrCl4+BCl3). SiHCl3, SiCl3and SiH2Cl2should be the crucial intermediates in the process of CVD Si3N4and could participate in the competition in deposition process. The results in this work were instructive for further investigation on the experiments under different conditions.
Preparation and Characterisation of Wool-Keratin Films Based on SMS Nonwovens
Authors: Li Jian Qiang , Zhang Ru Quan , Zhou Xiao Jie , Li Dai Qi
Published: February 2011

Keratins from wool were reduced by the optimize method(PH 7.0, NaHSO3 50wt%, Urea 200wt% and SDS 15wt%), wool 5g, distilled water100mL, shaken at 80°C inconstant temperature water-bath for 24h, filtered through different nylon screens with 50-300 aperture using decompression filtering, dialyzed against distilled water afford a colorless and clear solution. The keratins main molecular weight was 35,000-45,000 Daltons; a clear film is readily prepared from a keratin solution containing glycerol or PEG on the basic of SMS nonwovens; the films moisture content was changed while glycerol concentration changed from 5% to 25%; the film was insoluble in water and organic solvents. The films were tested by SEM, Ultraviolet and FTIR.
Preparation and Characterisation of Sulfonic Acid-Functionalized Carbon/Loess Composite
Authors: Zhang De Yi , Ma Ying , Wang Yi , Feng Hui Xia , Chen Jiao , Zhu Jia Can , Hao Yuan
Published: February 2011

In this paper, a novel sulfonic acid-functionalized carbon/loess composite was prepared using sucrose as carbon source and loess as raw material. The characterization results shown that plenty of carbon particles distribute on the surface of the composite, and an abundant of SO3H groups were successfully introduced onto the surface of the prepared composite through incomplete carbonization of sucrose and sulfonation of carbon particles. The adsorption capacity of the prepared composite for typical heavy metal ions also was investigated and compared with activated carbon, the results show that the composite shows excellent adsorprion performance, and the adsorption capacity for Fe3+, Pb2+, Cu2+, Cd2+, Ni2+ can reach about 412%, 249%, 153%, 134% and 120% of the capacity of activated carbon, respectively. The prepared composite with excellent adsorption performance could be used as a low-cost alternative to activated carbon for the removal of heavy metal ions from wastewater.
Melting Temperature of a Selected Area in CaO-MgO-Al2O3-SiO2 Slag System
Authors: Xu Ji Fang , Zhang Jie Yu , Jie Chang , Tang Lei , Chou Kuo Chih
Published: February 2011

The characteristic temperatures of the selected quaternary CaO-MgO-Al2O3-SiO2 slags have been measured by the hemisphere method. The effects of the basicity value and Al2O3 content studied. The results indicated that basicity and the Al2O3 content had obvious influence on the characteristic temperatures of the selected slags. All of the softening temperature, the hemisphere temperature and the flow temperature decrease with the increasing of the basicity value. Under the same content of CaO, the characteristic temperature decreased sharply by adding Al2O3. The solidus and liquidus temperatures computed from the FactSage database were compared with the present experimental observations as well as the melting temperature information of the DSC measurements. The results also indicated that it is possible to get a reasonable idea of the solidus temperature from the hemisphere temperature while the flow temperature would indicate the liquidus temperature.
Preparation and Properties of Tapioca Starch-Banana Fiber Composites Modified with Magnesium Hydroxide
Authors: Mo Xian Zhong , Qi Xiang , Zhong Yu Xiang , Li Ren Huan , Mo Chen
Published: February 2011

Banana fiber/tapioca starch (BFRTPS) composites modified by magnesium hydroxide (Mg(OH)2) were prepared with glycerin as the plasticizer, banana fiber as reinforcement and thermoplastic tapioca starch as matrix. Rheological properties testing showed that Mg(OH)2 take a strong effect to the preparation processing and made it hard to mix while the content increasing. Mechanical properties testing revealed that at the range of the Mg(OH)2 content from 5 to 20phr, the tensile strength of the composites increased from 12.8MPa to 24.8MPa at 15phr Mg(OH)2 content, but its elastic modulus was increased with the increasing of Mg(OH)2, reached the maximum of 3100MPa at 20phr Mg(OH)2 content. Obviously, Mg(OH)2 has an enforced effect to the composites. Combustion performances of the composites was improved by Mg(OH)2, the limited oxygen index(LOI) of the composites reached to 31% while the content of Mg(OH)2 was 20phr, and then the result of flammability testing achieved UL94HF-1 and UL94 V-0 level.
Microstructure and Mechanical Property of an ECAP Processed Al-Mg2Si In Situ Composite by Using a Combined Route
Authors: Bian Li Ping , Liang Wei , Zhang Wen Li
Published: February 2011

Microstructure and mechanical property of a hypoeutectic Al-Mg2Si composite processed by equal channel angular pressing up to eight passes in a combined route 2A+4BA+2A were investigated. The results show that the initial developed eutectic Mg2Si was significantly refined into submicrometer-scale particles and distributed homogeneously in the Al matrix, which together with the refinement of Al matrix leads to a much higher ductility with the elongation to failure up to 24% and a significantly enhanced ultimate tensile strength of 284MPa in the processed composite, increased by 2300% and 70%, respectively, compared to those in its as-cast counterpart.
Preparation and Characterisation of Polyborazine as Novel Precursor to Boron Nitride Ceramic
Authors: Deng Cheng , Song Yong Cai , Zhu Meng Fu , Su Hong Bo , You Xiu Dong , Chen Ping
Published: February 2011

A processable polyborazine precursor was synthesized via substitution reaction and deamine condensation reaction by using methylamine, propylamine and B-trichloroborazine (TCB) as the starting materials. The chemical composition, structure and properties of the obtained polymer were investigated using element analysis, FT-IR, NMR, XPS and TG. The results indicated that the backbone of the polymer was approximate linear arrangement of boron-nitride ring molecules with B-N(CH3)-B structure as bridge bond, meanwhile minor amount of methylamino and propylamino remained in polyborazine as the pendant or end group. The melting point, number average molecular weight and polydispersity index of polyborazine was 90°С , 1002 and 1.355, respectively. The polyborazine showed good processability and polyborazine precursor fibers with diameter of 10~15 µm could be obtained by melt-spinning in N2 atmosphere. The ceramic yield of the polyborazine at 1000°С in nitrogen atmosphere was 53.2 wt%, which suggested that the as-achieved polymer can be used as a precursor to boron nitride ceramic fibers and membranes.
Effects of Temperature and Strain Rate on Thermal Deformation-Behaviour of Cu-P Weathering Steel
Authors: Zhang Xin , Xiong Yi
Published: February 2011

The effects of temperature and strain rate on the thermal deformation-behavior of Cu-P weathering steel were studied by using thermal simulator. And the true stress-true strain curves at different thermal deformation conditions were got. Then the features of the microstructure of the steel under different temperatures and strain rates were analyzed. The results show that with the same deformation dimensions and strain rates, when the deformation temperatures were higher, the recrystallization would proceed much easier, and the size of the recrystal grains could be also larger. And with the same deformation dimensions and temperatures, when the strain rates were lower, the recrystallization could also occur easier, and the proportion and size of the recrystal grains were larger.
Microstructure and Mechanical Properties of High-Strength Graphite Particles Coated TiO2 Film Embedded in SiC Composite
Authors: Yu Liang , Jiang Yan Li , Kan Dong , Ru Hong Qiang
Published: February 2011

In order to improve the fracture strength of Gp/SiC composites, the mean size (d50) 50 μm high-strength graphite particles, TiCl4 used as starting materials, and the graphite particles coated TiO2 film were obtained using co-precipitation method. Then the Gp/SiC composites were prepared with the “roll the snowball method” and hot-pressing sintering technology. The microstructure and phase constitution is measured by scanning electron microscopy (SEM) and electron energy spectrum (EDS). It is found that the coated graphite cores are embedded in the SiC matrix as the islands. The apparent porosity increases, density decreases, with graphite content increasing. The fracture strength and hardness decrease, fracture toughness increases with the graphite content increasing. The apparent porosity, density, fracture strength, fracture toughness, hardness of the composite are 3.8%, 2.61 g•cm-3,135 MPa, 2.82 MPa•m1/2,22.1 GPa, respectively, while the volume percent of ceramic and graphite is 6︰4 and sintered at 2000°C. The TiO2 film can effectively lower the sintering temperature and impart composite better mechanical properties. The toughening mechanisms are crack deflection and branching as well as stress relaxation near the crack tip.
Microstructure of In Situ Tic-Mo-Ni And Tic-WC-Mo-Ni Cermets Synthesized by Reactive Hot-Pressing Sintering
Authors: Liu Zong De , Zhao Li Ping , Bao Yan Rong , Li Bin
Published: February 2011

TiC-Mo-Ni and TiC-WC-Mo-Ni cermet blocks have been obtained in situ by reactive hot pressing sintering. The phase structure and microstructure of the two cermets were compared to investigate the effect of the addition of WC. The results show that the chemical reactions between Ti, Mo and C in TiC-Mo-Ni system are relatively complete. However, there is a small amount of unreacted C powder in TiC-WC-Mo-Ni system, which is associated with the reaction between Ti and WC. The in-situ carbide grains are very fine with the size range of 0.5-2µm. The boundary morphology between the carbide grains and the binder phase changes from an angular shape to an almost rounded shape with the addition of WC.
Microstructure Characterisation and Mechanical Behaviour of 2D C/SiC-C Composite with SiC/PyC Multilayer Matrix
Authors: Meng Zhi Xin , Cheng Lai Fei , Liu Qiao Mu , Han Xiu Feng , Zhang Li Tong
Published: February 2011

Two composites of 2D C/SiC-C and 2D C/SiC were fabricated by isothermal-isobaric chemical vapor infiltration (ICVI). The microstructures and mechanical behaviors at room temperature were characterized and investigated, respectively. In the 2D C/SiC-C composite, the PyC matrix layers are homogeneous and continuous. Moreover, the matrix layers of SiC and PyC bond well and almost no microcracks are found in the multilayered matrix. Compared with the 2D C/SiC composite, the 2D C/SiC-C composite exihibits improved mechanical properties.The successive extraction of matrix layers and multiple deflections of cracks in the SiC/PyC multilayered matrix contribute to the improvement of mechanical properties.
Experiment Research on Argon Shroud for the Protection of Steel Casting
Authors: Gong Zhi Jun , Song Wei , Ma Yong Lin
Published: February 2011

Physical modeling of argon shroud was carried out using a 2D 1:1 scaled model in order to gain the protection effect in steel casting. The speed field of protective gas around the steel steam was measured by PIV technique. The oxygen distribution was measured by an oxygen sensor. The main findings are following: (1)The distance between the ladle and the collar should be minimized to reduce the oxygen entrainment.(2)For single inlet, the oxygen contents were lower in the case of horizontal gas inlet than vertical gas inlet.(3)A dual gas inlet configuration would be more effective than a single inlet in ordinary operation conditions.
Chemical Modification of Poplar Wood on the Mechanical Properties
Authors: Wu Guo Feng , Lang Qian , Wang Bin , Jiang Yi Fei , Pu Jun Wen
Published: February 2011

In this research, the chemical and multilayer hot-press drying was used to modify poplar wood. The timbers were compressed and dried in the multilayer hot-press drying kiln. The combination of chemical modification and hot-press drying can improve the mechanical properties. The influence of chemical and hot-press drying on the compressive strength parallel to grain, the bending strength, the density, the water absorbent and the crystallinity of poplar wood have been investigated in this study. The chemical treated conditions close to real technological regimes selected. The samples were impregnated with three conditions. The samples were dried in a hot-press drying kiln for 130hrs. It was showed that the urea carbamate and hot-press drying treatment increase the properties. The density and mechanical properties increased with increasing urea carbamate, while the water absorption decreased. The crystallinity is 37.03%, 37.11%, 37.78%, separately, compared with the natural wood of 35.09%. The TAG showed the thermal stability increased.
Three-Dimensional Effective Elastic Moduli for Multidirectional Filament-Wound Tube with Lining
Authors: Xu Guang Lei , Ruan Wen Jun , Wang Hao , Yang Qing Ping , Liu Jia Wen
Published: February 2011

A method based on laminate theory is presented for estimating three-dimensional effective elastic moduli of multidirectional filament-wound fibre-reinforced composite thin-wall tube with lining. The effective elastic moduli of glass fibre wound tube with lining are calculated. In contrast with finite element analysis, effective elastic moduli estimated by this method are accurate.
Effects of Fe on Friction and Wear Properties of Cu-Based Friction Aterial
Authors: Fu Rong , Gao Fei , Song Bao Yun
Published: February 2011

Cu-Fe sintered material is prepared by PM technique, and the effect of Fe content on friction property of material and the relation between Fe content and the shape of the third body are investivaged by a constant speed friction test machine. The result indicates that as Fe content in the material increased, material density and porosity haven’t changed much, while material hardness obviously increased. When Fe content is about 20%, friction and wear properties are better because the optimum amount of Fe has the function of strengthening matrix. As friction speed increased, friction coefficient reduced; the cause lies in the fact that surface temperature rise reduces the density of Cu matrix and reduces mechanical meshing drag between micro-convex bodies due to poor thermal conductance of Fe. Simultaneously, due to friction alternating stress, rigid and fragile third body with advanced oxidization generates micro cracks, and the micro cracks continuously expand, and finally drop off; thus, the wear rate is increased.
Study on Porous Structure and Surface Characteristics of Al-Pillared Montmorillonite
Authors: Wang Gui Fang , Ma Shao Jian , Zhang Shuai , Lu Xian Jun , Mo Wei , Yang Jin Lin
Published: February 2011

Al-pillared montmorillonite (Al-PILM) prepared with Keggin ions was studied by means of XRD, SEM-EDS and N2 adsorption-desorption isotherms.The rusults show that, compared to unpillared Na-montmorillonite (Na-M), the interlayer spacing d(001) value, BET specific surface area, surface fractal dimension and the proportion of microporous specific surface area of Al-PILM are larger and the surface is relatively rough. The BJH porous volume distribution of Al-PILM is the most probable distribution, and the most probable pore size is about 2 nm, belonging to mesopore. The porous structure of Al-PILM is characterized as parallel plate slit or “house-of-cards” wedge-shaped pore which is formed by novel meso-microporous delaminated structure and fragments. Besides, the results of elemental distribution show that the ions exchange action between Na+ and hydroxy-Al cations in pillaring solution occurs in the formation of Al-PILM.
Experimental Study on Applying Bentonite for Mango Storage
Authors: Mo Wei , Feng Jin Peng , Ma Shao Jian , Gao Ying , Liu Kun , Su Xiu Juan
Published: February 2011

In this paper, bentonite was applied in mango preservation, and the effects of various treatments methods on fresh-cut mango were studied.The results indicated that mangoes without any treatment easily rotted. The quality indexes of mango such as the weight loss rate, the disease rate and the turning yellow rate tend to increase while the titratable acidity and vitamin C content of mango lose largely. However, the weight loss rate, the disease rate and the turning yellow rate of mango may be reduced when mango were packed in seal bags together with bentonite. Purified bentonite is better than raw bentonite when applied in keeping mango fresh. Burying mango in mass purified bentonite was advisable for mango preservation.
Study on Preparation Technique of SiC/Cu-Al Composite by Pressureless Infiltration
Authors: Du Shuang Ming , Hu Chen , Wang Ming Jing , Zhao Wei Tao
Published: February 2011

In order to improve the compatibility between SiC particles and aluminum, the SiC/Cu composite powders were prepared by using chemical plating method to coat a Cu layer on the SiC particles surface. The obtained powders were made into preform and then put it into molten aluminium. SiC/Cu-Al composite were produced by using pressureless infiltration method under argon gas. By scanning electron microscopy (SEM), optical microscopy (OM), X-ray diffraction (XRD),the phase structure and microstructure of SiC/Cu composite powders and SiC/Cu-Al composite were analysed. Moreover, the temperature and soaking time on the effect of SiC/Cu-Al composite infiltration depth and effect were studied. The results show that: Cu coating on the SiC particles surface distributed uniformly; SiC/Cu-Al composite prepared at the condition of 800°C and 2 hours soaking time has a densification microstructure, SiC particles uniformly distributed in the aluminum matrix and there is no Al4C3 brittle phase formation; at 700°C～900°C infiltration, as the temperature growing, infiltration depth increases at first and then decreases; the microstructure of SiC/Cu-Al composite which infiltrated 2 hours is more compact than that 1 hour; Cu coating effectively improved the wettability between SiC particles and molten aluminum, and inhibited the formation of harmful interfacial reaction.
TRIZ and its Application in Industrial Design
Authors: Zhang Jian Yi , Cao Jun Qiang
Published: February 2011

Industrial design is a design practical activity based on innovation. TRIZ is a method and tool about systematic innovation. The invention principles of TRIZ are suitable for finding a new path of industrial design. This paper analyses the basic principle of TRIZ theory, and discusses the application of the principle of TRIZ in industrial design field. On the basis of the theory of TRIZ, two new products are designed. The corresponding result shows the combination of industrial design and innovation methods will promote industrial design.
Seismic Performance of CFRP Strengthened Unreinforced Masonry Structures
Authors: Yuan Sheng Li
Published: February 2011

This paper studies the earthquake performance of strengthening unreinforced masonry structures with CFRP. Using CFRP reinforced masonry structures can substantially increase the ultimate flexural strength and resisted deformations of the walls and columns ,at the same time can also effectively dispersed the distribution of crack width of cracks and constraints.
Experimental Research on Seismic Behaviour of Low-Carbon Construction Materials RAC Frame Columns
Authors: Liu Chao , Bai Guo Liang , Zhao Hong Jin
Published: February 2011

A comparative study is conducted on the seismic behaviors of three recycled aggregate concrete (RAC) frame columns under low cyclic load. The recycled aggregate replacement rate is 0%, 50%, 100% respectively. The mechanical characteristics, failure mode, hysteresis loops, ductility and consumption characteristics of frame columns with different recycled aggregate replacement rate and same axial compression ratio are analyzed in this paper comparatively. The rule characteristics between ordinary concrete and recycled aggregate concrete frame columns are found. The result indicates that failure process of recycled aggregate concrete frame columns is similar to that of ordinary concrete. The seismic behaviors of recycled aggregate concrete frame columns, including the ductility etc., still meet the related requirements of earthquake-resistance designing. So it is concluded in this paper that the recycled aggregate concrete can be applied in concrete structures. Because of its properties are certain deficiencies, some tectonic measures must be enhanced.
The Evaluation of Organic Coating with Artificial Defect Degradation with EIS Measurement: Phase Angle at High Frequencies
Authors: Liu Jie , Li Xiang Bo , Wang Jia , Li Shou Biao
Published: February 2011

Electrochemical impedance spectra (EIS) of two kinds of damage rate samples in natural seawater were measured and the relations between coating resistances and phase angles at high frequencies were analyzed. The results indicated that for the coating systems studied, the variation of phase angles at 14 kHz with immersion time was very close to the variation of coating resistance, hence may qualitatively reﬂect the coating with artificial defect degradation. This approach contains no error in calculation and the special phase angle parameters could be extracted easily from the EIS measured data. These phase angle parameters may be used as quick measurements to evaluate coating with artificial defect performance.
Surface Characterisation of the Corundum-Route Lead Magnesium Niobate Ferroelectric Ceramics
Authors: Srisombat Laongnuan , Wongmaneerung Rewadee , Yimnirun Rattikorn , Ananta Supon
Published: February 2011

Perovskite relaxor ferroelectric PMN ceramics, Pb (Mg1/3Nb2/3O3), have been fabricated using a two-stage process employing a corundum-type Mg4Nb2O9 as a key precursor. The 100% perovskite PMN ceramics was revealed by X-ray diffraction analysis. The SEM image of the PMN ceramic shows irregular shape PMN grains on the porous surface. The surface chemical composition of the PMN ceramics could be characterized by X-ray photoelectron microscopy technique. The XPS results indicate most of the elements consist of more than one chemical species. The important of XPS studies here can reveal small amount of species which could not detected by XRD.
Hydration Characteristics and Cementious Properties of Pyrolytic Steel Slag
Authors: Ouyang Dong , Yi Cheng Bo , Xu Wei Ting , Lu Liu Lei
Published: February 2011

This study was to investigate the hydration characteristics and cementious properties of pyrolytic steel slag（PSS）. Initially, PSS pastes were made to determine the hydration characteristics of PSS and the results indicated that the hydration activity of PSS with 6.4% gypsum content was stronger than that of paste with pure PSS. Afterwards, compressive strength of mortars were tested and the results showed that cement mortars with 0% to 30% replacement of PSS satisfied the requirements of activity index class of 80% at 28 days. As an activator, gypsum was supiror to calcium hydroxide in performance.
Effect of Brown Corundum Dust Powder on the Sintering Performance of Corundum-Silicon Nitride Castable
Authors: Xue Wen Dong , Li Yong , Tong Jing , Huang Xiao Xiao , Sun Jia Lin
Published: February 2011

The sintering performance of corundum-silicon nitride castable with brown corundum dust powder added was studied in this paper to provide a theoretical basis for the reuse of this waste powder. Waste powder, corundum, silicon nitride and silicon carbide were used as raw materials in this experiment. The sintered samples were measured routine physical property, and analyzed the microstructure of samples by SEM. Results shows that the addition of dusting powder could promote the sintering performance of non-oxides and the formation of Sialon, and improve the physical properties of samples. But when dusting powder added over 6% of the total, there are too much liquid phases, which will reduce the fire resistance performance at high temperature, so the appropriate added amount of dusting powder should be less than 6%.
Effect of Microwave-Treatment Power on the Properties of Activated Carbons as Electrode Materials for Supercapacitors
Authors: He Xiao Jun , Li Ru Chun , Zheng Ming Dong , Wang Ting , Zhang Xiao Yong
Published: February 2011

Activated carbons (ACs) from petroleum coke by microwave heating KOH activation are treated by microwave to investigate the effect of microwave−treatment power on AC properties. The electrochemical properties of AC electrodes for supercapacitors were investigated by cyclic voltammetry, constant current charge−discharge and electrochemical impedance spectroscopy. The results showed that specific surface area (SBET) and total pore volume of microwave−treated ACs, specific capacitance and energy density of microwave−treated AC electrodes decreased. The electrical conductivity and stability of AC electrodes for supercapacitors were improved. Fast microwave−treatment is an efficient method to obtain suitable ACs for supercapacitors.