bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructure Characterization and Abrasive Wear Performance of HVOF Sprayed WC-Co Coatings
Authors: Wang Hong Tao , Ji Gang Chang , Chen Qing Yu , Du Xue Fei , Fu Wei
Published: February 2011

In this paper the nanostructured and conventional WC-12Co feedstock powders were thermally sprayed via high velocity oxy-fuel (HVOF) on the mild steel substrate. The influence of the feedstock powder type on the microstructure of coatings and abrasive wear resistance properties was studied. The correlation between the coating microstructure and the wear performance was investigated by analyzing the microstructure and worn surface morphology of the coatings. The results indicated that the nanostructured coating shows higher porosity, but slightly higher microhardness and better abrasive wear resistance than the conventional counterpart. Also, the two coatings have excellent abrasive wear resistance with respect to the substrate.
Functional Evaluation Software Design of Surface Topography Based on MATLAB
Authors: Huang Mei Fa , Cheng Xiong , Liu Hui Fen , Huang Jiang Tai , Kuang Bing
Published: February 2011

In order to build the software evaluation and testing platform for surface topography measuring device and related enterprise, it is urgent to exploit the surface topography measurement and evaluation standard software application system. This paper proposes a novel method of surface topography design software base on exiting international standards. The method is introduced to obtain the reference line of surface profile. According to the reference line of surface roughness defined by the related standards, the functional evaluation parameters of surface characteristics were calculated. The procedure in designing the graphical user interface (GUI) is given based on the MATLAB software platform. This method realizes the software system that can evaluate the parameters of surface topography. The experimental analysis results show that the surface topography functional evaluation software using MATLAB has simple structure and reliable performance.
Study on the Incline Limit in Gas Metal Arc Welding Based Rapid Forming
Authors: Yin Feng Liang , Zhu Sheng , Liu Jian , Wang Qi Wei
Published: February 2011

The paper defined a concept of the utmost shapeable angle for the gas metal arc welding based rapid forming process, which is used to judge supporting material need to be employed or not when a inclined wall is deposited. If the angle formed by the outer normal of the inclined wall and building direction exceeds the sum of the utmost shapeable angle and π/2, then supporting material must be deposited to finish the inclined wall along the given building direction. The effects of metal transfer mode and welding speed on the utmost shapeable angle were studied. It is found that the ‘one droplet per pulse’ metal transfer mode in pulse-current welding based RP may obtain a bigger utmost shapeable angle than short circuit metal transfer mode does. The welding speed influences the utmost shapeable angle through heat input and bead profile. An abrupt bead is harmful to get a bigger utmost shapeable angle. Within a welding speed extension from 9 mm/s to 30 mm/s, the utmost shapeable angle gets the maximum value of 55° when the welding speed is 18 mm/s.
The High-Temperature Oxidation Behavior of the Fe-Ni Based Alloy Coating Produced by Plasma Cladding
Authors: Zhang Li Min , Liu Bang Wu
Published: February 2011

In the paper the efficient and low-cost plasma cladding technique has been used to prepare Fe-Ni based alloy coatings on the surface of low carbon steel. The high-temperature isothermal oxidation behavior of the specimens has been tested at 700 °C and 800 °C in air using an electrical furnace for 100 h. The elements distribution, phase composition, and morphology of the alloy coatings after the oxidation test have been characterized by SEM/EDS and XRD. Isothermal oxidation test show that the Fe-Ni based alloy coating has excellent high temperature oxidation resistance at 700 °C and 800 °C. The oxidation rate of Fe-Ni based coating at 800 °C is higher than that of at 700 °C. At 800 °C, the oxidation kinetics basically follows the parabolic rate law before 80 h. A protective Fe0.99Fe1.97Cr0.03Ni0.01O4 and Cr1.3Fe0.7O3 based oxide film has been formed on the surface of the coating after oxidation.
A Study on Dieless Incremental Sheet Metal Forming Using Water Jet Technology
Authors: Kai He , Li Jiu Hua , Luo Qun , Mao He , Du Ru Xu
Published: February 2011

A new method of sheet metal forming, water jet incremental sheet metal forming (WJISMF) is presented. We give the schematic illustration of WJISMF system, which includes high pressure system, NC machine, control system, water recycle system, and some attachments, and then the virtual prototype of the system is designed. To predict the whole deformation process, some simulations are carried out. Firstly, fluid structure interaction simulation for WJISMF is performed. The water jet is modeled and simulated with a computational fluid dynamics (CFD) approach, while for the material flow in the workpiece a finite element analysis (FEA) is used. Secondly, the relationship between the workpiece material deformation and nozzle diameter, and the relationship between deformation and water pressure are presented. Thirdly, the fluid structure interaction simulation model is simplified to the structure simulation model, by adopting shell 181 element and using a pressure acting on the workpiece directly instead of the CFD model. Finally, a simulation for forming a cone box is done using the simplified model. The simulation provides a powerful rationale for the practical application of WJISMF.
The Influence of Coating on the Elastic Modulus of Basalt Filament Diaphragm Fabric
Authors: Guo Zong Fu , Zhong Zhi Li
Published: February 2011

This paper focuses on the influences of the technologies such as curing time, curing temperature and coating on the elastic modulus of basalt filament diaphragm fabric. This paper compares the elastic modulus of basalt filament diaphragm fabric with that of glass fiber diaphragm fabric under the same fabric density, texture and coating thickness, thus discusses the feasibility of using basalt filament as cone material. In the experiment, we use CSW-03 loom to weave basalt filament diaphragm fabric and glass fiber diaphragm fabric, then we use Werner Mathis AG LTF97885 coating machine to coat them and then use 3380Instron advanced testing machine to test the elastic modulus and the breaking strength. Conclusion: The coating curing effect, the elastic modulus and the breaking strength will reach their best when the temperature is 120°C, the time is 30 minutes. When the coating thickness is 0.05mm, the elastic modulus of basalt filament diaphragm fabric will be best. So considering the elastic modulus, basalt filament diaphragm fabric is more suitable than glass fiber diaphragm fabric. The result of this paper can be used as theoretical basis for the development of basalt filament diaphragm fabric. So we can develop more materials related to basalt filament diaphragm fabric to enhance market competitiveness.
Research on the Microstructure and Wear Resistance of Hardfacing Layer on Big Cold Trimming Die Insert
Authors: Shi Jian Ping , He Bo Lin , Yu Ying Xia , Liu Jing
Published: February 2011

It’s a simple technology to manufacture big trimming die by hardfacing on the die insert of cast iron. Here, the chemical composition, microstructure, micro-hardness, wear resistance and wear mechanism of the hardfacing layer with a newly developed electrode have been studied. The experimental results indicate that the hardfacing technology has much more advantages and cheaper than that of traditional process. The chemical composition, microstructure, micro-hardness of the hardfacing metal are all satisfied for manufacturing the big trimming die by welding on die insert of cast iron. The wear resistant test of hardfacing layers were carried out by using M2000 type tester with two different electrodes. The wear resistance of new electrode hardfacing layer is higher than that of normal hardfacing electrode D322. The wear mechanism of hardfacing layer belongs to abrasive wear model. The service life of hardfacing die insert is as long as tool steel insert which was fully heat-treated. More than 25000 workpieces can be carried out by using the hardfacing die insert. The life of repaired cold die with new kind of hardfacing electrode bar can be raised up to 30~50% than that with the electrode D322 under the same condition.
Study of the Ce-Mn Conversion Coating on 6061 Aluminium Alloy
Authors: Zhang Jun Jun , Han Dong , Li Wen Fang , Du Jun
Published: February 2011

In this work, the green chemistry conversion coating on 6063 aluminium alloy surface was made and studied by means of (NH4)2Ce(NO3)6-H2O2 as inhibitor, HF-FeCl3 as accelerator. The coating was evaluated in 3.5% NaCl at room temperature by using polarization curve and electrochemical impedance spectroscopy (EIS). The results show the corrosion current density and the conversion coating resistance, for the untreated or treated alloy, are 1.566 uA•cm-2 and 6.621kΩ cm2, 0.0545 uA•cm-2 and 208.56 kΩ cm2 respectively. It indicates the (NH4)2Ce(NO3)6-H2O2 treated surface presents better corrosion behaviour in chloride media than the original material surface. The morphologies, composition and valence state of the coating were examined by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray photoelectron spectroscopy (XPS), respectively. The result indicates that the Ce-Mn conversion coating was made on aluminium alloy surface.
Study on the Mechanical Properties of PP/EPDM/Mesoporous MCM-41 Composites
Authors: Wang Na , Wang Xiang Zhou , Fang Qing Hong , Chen Er Fan
Published: February 2011

Nano-sized as-synthesized MCM-41 (with template) particle, whose pore channels and outer surface are full of organic CTAB template, is used as compatibilizers for immiscible polypropylene (PP)/ethylene–propylene–diene terpolymer (EPDM) blends. The mechanical properties of PP/EPDM/mesoporous MCM-41 ternary composites are investigated. The nano-structured MCM-41 (without template) material constituted by an ordered network of hexagonal channels is selected to compare with as-synthesized MCM-41 (with template) in mechanical properties of PP/EPDM blend. The results shows that tensile strength of the blend is increased by 13.6% and the impact strength is increased by 71.6% by addition 2 wt% content of as-synthesized MCM-41 (with template) compared to pure PP/EPDM. The presence of MCM-41(without template) in the blend cannot improve the mechanical properties obviously. SEM reveals that the enhancement of the interface is obtained by adding MCM-41 (with template). SEM also indicates that incorporation of as-synthesized MCM-41 (with template) into PP/EPDM blend can act as compatibilizer, which results in a decreased particle size of dispersion phase together with morphological evidence of interfacial adhesion. However, with the presence of MCM-41 (without template), the interface do not show clearly change compared with the PP/EPDM blend. The PP/EPDM/MCM-41 (with template) composites show higher tensile strength and impact strength than the PP /EPDM / MCM-41 (without template).
Observation and Removal of Atmospheric Micro-Contaminants on SUS304 Steel
Authors: Wang Rong Guang , Kido Mitsuo , Nakanishi Suketsuku , Okabe Takuji
Published: February 2011

Micro-contaminants on SUS304 stainless steel were observed and confirmed by atomic force microscope, and the micro-contaminant removal was carried out by ultraviolet (UV) illumination. The amount of micro-contaminants on the specimen surface decreased with an increase in the UV illumination time, with extensive removal of the organic substance in the contaminants but leaving part of the contained water in the contaminants. The surface for macro-droplets after the UV illumination became hydrophilic, while no large change of the wettability for micro-droplets on the same surface can be observed.
Effects of Ultrasonic Deep Rolling on Fatigue Performance of Pre-Corroded 7A52 Aluminum Alloy
Authors: Ye Xiong Lin , Zhu You Li , Zhang Dong Hu
Published: February 2011

The effects of ultrasonic deep rolling (UDR) on the fatigue behavior of pre-corroded 7A52 aluminum alloys were investigated. By means of X-Ray diffraction stress measurements and scanning electron microscopy (SEM), residual stress and fractograph of 7A52 aluminum alloys with and without UDR treatment were analyzed. The results indicated that the UDR produced compressive residual stresses with depth approaching 1mm. UDR treatment can extend the fatigue life of the pre-corroded 7A52 specimens to a large extent, depending on the level of corrosion and UDR parameter. For the slightly corrode specimens, the UDR treatment changed the fatigue crack nucleation site from surface to the transition zone between the compressive residual stresses and tensile stresses, resulted in a much longer fatigue life. For the severely corrode specimens, the crack still nucleated by intergranular cracking, however, due to the compressive residual stresses introduced and the closure of the corrosion pits and corrosion micro-crocks, UDR treatment still improved fatigue performance of the pre-corroded 7A52 aluminum alloy substantially.
The Evaluation of NHW-1 Type Coated Tubing Abrasion Resistance Performance
Authors: Wang Ke Liang , Liu Yang , Sun Li Jing , Sun Chun Bao
Published: February 2011

The eccentric wear of the sucker rods and tubes has already become the greatest bottleneck restricting the development of oil recovery technology of pumping wells. There is lots of inadaptability of the current control measures. The laboratory study and field tests showed that the NHW-1type coated tubing had a good protection of the rods and tubes of the well pumps. Compared with ordinary tubing, coating can prolong the life cycle of the tubes for more than 2.6 times. At present, the eccentric wear control technology is advanced both at home and abroad.
Application of Monte Carlo Method in the Measurement Process Design According to next Generation of GPS
Authors: Zhang Ya , Fu Jian Zhong , Chen Zi Chen
Published: February 2011

Measurement process has an important impact on the reliability of measurement. The reliability of measurement is weighed by measurement uncertainty. It is very difficult to estimate the uncertainty in the indirect measurements according to the transfer formula given by GUM (Guide to the Expression of Uncertainty in Measurement). Monte Carlo method was proposed to solve the problem of uncertainty estimation and seek suitable measurement process in the indirect measurements. The mathematical relation between the measurand and the direct measures is established firstly. Then Monte Carlo method was adopted to conduct the sampling and synthesis of measurement uncertainty contributors. At last, the measurement method was evaluated and improved according to Procedure for Uncertainty Management, which is given by next generation of GPS (Geometrical Product Specification). Experimental result shows that Monte Carlo Simulation method has a good application foreground in the uncertainty estimation and measurement process design.
Research on Anti-Cracking Performance of Polypropylene Fiber Reinforced Cement Mortar
Authors: Xu Hong Shen , Cao Yong Min , Sun Hong Ming
Published: February 2011

Adding suitable quantity of polypropylene fiber is very effective for controlling plastic crack of cement mortar. During the experience stage, adding quantity of polypropylene fiber is 1.5 kg/m3, and crack rate of mortar is only 7.7%. Theoretical analysis is made for plastic crack mechanism of cement mortar, the results indicate that adding polypropylene fiber improves critical stress of crack expansion in mortar and notably reduces crack of cement mortar.
Microscopic Mechanism Study on Carbonation Resistance of Recycled Aggregate Concrete
Authors: Yang Hai Feng , Deng Zhi Heng , Li Xue Liang
Published: February 2011

24 100mm × 100mm × 300mm recycled concrete prisms and 96 150mm × 150mm × 150mm cubes are completed in this paper.The relationships of the carbonation depth in each carbonation age with replacement rate of recycled coarse aggregate and fly ash is studied; The SEM is used to observe the interface structure of recycled coarse aggregate concrete and compared with ordinary concrete, and finally,a recycled concrete carbonation model is proposed. The results showed that: the substitution of recycled coarse aggregate and fly ash cut down the recycled concrete carbonation resistance significantly, which are related with the replacement rate; the content of Ca(OH)2 in the recycled aggregate concrete decreased ,also there are obvious interface transition zone between the recycled coarse aggregate and the new cement;obvious cracks and large voids are exist before the recycled aggregate concrete is loaded, which lead directly to lower carbonation resistance of the recycled concrete.
A Study for Substituting Part of Raw Materials by Bottom Ash in Portland Cement
Authors: Hsu Hui Mi , Chen Hao Hsien , Chao Sao Jeng , Cheng An , Wu Cheng Yang , Ma Chuan Tsung
Published: February 2011

The disposal and reuse of waste combustion residues has become a critical topic recently in view of the method of treating household wastes in a city, which has gradually changed to be incineration (major) and landfill (minor) in densely populated Taiwan, plus the difficulty of various wastes disposed by the Refuse Incineration Plant at Yilan County. To propose concrete recommendations as references for the local competent authorities’ policy for reuse of bottom ash, we researched and analyzed compositions of wastes and ingredients as well as leaching toxicity of bottom ash (accounting for 70% of waste combustion residues) which had been collected from the Li-Ze Incineration plant at Yilan, and transported bottom ash to a cement plant also at Yilan as an alternative material for Portland cement. The results in this study indicated quite a few products, with ingredients of bottom ash from an incineration plant, can be taken as principal compositions used in production of cement, and the capacity of bottom ash treated by the cement plant can be further expanded according to the quality of produced cement and bottom ash properly processed.
Research on Mechanical Property of Single Panel Fire-Resistant Glass with Cs+ Ion and Rb+ Ion Exchange
Authors: Wang Qing , Ding Zhao Yang , Da Jing , Zhang Jing , Sui Zhi Tong
Published: February 2011

The effect of Cs+ion and Rb+ion in the molten salt of different proportion on the single panel fire-resistant glass is discussed in this paper. The single panel fire-resistant glass was prepared by the method of ion-exchange, with proper amount of additives and adding KNO3and CsNO3, KNO3and RbNO3as the main part of molten salt. The proportion of the molten salt was changed separately, a contrast test was performed to measure the flexure strength. The results indicated that the flexure strength of the single panel fire-resistant glass increased firstly and then stabilized as the ratios of w(CsNO3)/w(KNO3) and w(CsNO3)/w(RbNO3) increased respectively. With the ratio of w(CsNO3)/w(KNO3) =1.5%, the mechanical property of the single panel fire-resistant glass was proper and the maximum flexure strength was 274 MPa. In the case of RbNO3, the flexure strength of single panel fire-resistant was 244 MPa with the ratio of w(CsNO3)/w(KNO3) = 0.3%. According to the research, it is found that the method of ion-exchange of Cs+ and Rb+ into plain glass to prepare single panel fire-resistant glass is feasible, the sample melted under the condition of 1 hour and 780 without any trace of thermal explosion.
Effects of Adhered Mortar Content on Quality of Recycled Coarse Aggregate of Concrete
Authors: Quan Hong Zhu
Published: February 2011

Although the adhered mortar content affects the properties of recycled aggregate concrete, there are few papers describing those effects. This paper presents the results of a series of experimental study on the effects of adhered mortar content on the quality of recycled coarse aggregate of concrete. 5 kinds recycled coarse aggregates made with heating and rubbing method, mechanical crashing method and separating lightweight particle with water stream method were tested for specific gravity, absorption and adhered mortar content. Specific gravity in oven-dried condition ranged from 2.35g/cm3 to 2.59 g/cm3, absorption ranged from 1.58% to 5.83% and adhered mortar content ranged from 8.0% to 68.4%, depending on manufacturing method of recycled aggregate. Absorption decreased linearly with the increase of specific gravity. Specific gravity decreased and absorption increased with the increase of adhered mortar content. Recycled aggregate made by heating and rubbing method showed lower adhered mortar content corresponding to lower absorption and higher specific gravity, while those made by mechanical crushing method showed higher adhered mortar content corresponding to higher absorption and lower specific gravity. In conclusion, the upper limit of adhered mortar content of recycled coarse aggregate is considered to be 15%, in order to keep up the quality of coarse aggregate and properties equal to natural coarse aggregate.
Preparation and Properties of New Polycarboxylate-Type Superplasticizer
Authors: Lv Sheng Hua , Gao Rui Jun , Duan Jian Ping , Yan Xiao Liang , Hou Ming Ming
Published: February 2011

A modified polycarboxylate superplasticizer was synthesized by copolymerization of polyethylene glycol monomethyl ether methacrylate (MPEG-MA), β–Cyclodextrins grafted maleic anhydride (MAH-β-CD), methacrylic acid (MAA) and methallyl sulfonic acid (MAS). The excellent superplasticizer was obtained at the molar ratio of n(MAH-β-CD) : n(MAS) : n(MAA) : n(MPEG-MA) was 0.05:0.1:3:1 using ammonium persulfate (APS) as initiator at 90°C for 5 h. The applied results show that the product had many advantages, such as lower dosage, longer setting time, better flow-keeping ability and better compatibility with different cement. Meanwhile, the structure and relative molecular weight were characterized by FTIR and GPC respectively.
Hypereutectic Al-Si-Mg In Situ Composite Prepared by Melt Superheating
Authors: Liu Zheng , Xie Min
Published: February 2011

Mg2Si particle reinforced hypereutectic Al-Si-Mg alloy composite is prepared by melt superheating, and the effects of the main processing parameters, such as superheating temperature and holding time, on the microstructure of the composite are studied. The results indicate that it is feasible to prepare Mg2Si particle reinforced Al-18%Si-Mg alloy composite by melt superheating. The suitable preparing parameters of melt superheating on the alloy are obtained. When the superheating temperature is 860°C and holding time is 25 min, the average size of Mg2Si particle in the alloy will be reduced to about 11μm compared with 34μm without melt superheating.
Impact Strength Test and Numerical Fitting of Plybamboo Form
Authors: Yu Yun Shui , Li Ben Gui , Zhou Wei Hong
Published: February 2011

longitudinal and transverse impact strength tests of plybamboo form with different moisture content were performed. Regression Equations of longitudinal and transverse impact strength of plybamboo form were constructed through numerical fitting. The results show that both longitudinal impact strength and transverse impact strength increase with the increasing of the moisture content of the plybamboo form. The average value of longitudinal impact strength increases or decreases 0.20kJ/m2 when the value of moisture content increases or decreases 1%. The average value of transverse impact strength increases or decreases 0.12kJ/m2 when the value of moisture content increases or decreases 1%. The results of variance analysis and significance test of the two linear regression equations show that both the regression equations achieve very significant level.
Reliability Research of RPC Low-Height T-Beam in Railway Bridge
Authors: Zhong Tie Yi , Zhang Ming Bo , Wang Wen Qiu
Published: February 2011

Reactive powder concrete (RPC) is one of new composite material, which is applied in the pilot project of the railways construction. According to the literature survey and test data report, the major factors which influence the reliability of 32m prestressed RPC girder in railway bridges are given in this paper. Furthermore, combining numerical simulation with finite-element method, the reliability of the prestressed RPC girder is calculated. The results show that the failure probability and reliability parameter can be obtained through direct sampling method and the latin hypercubic sampling method. The reliability parameter of fracture is 3.9 with two methods, while the reliability parameter of deflection control is 4.1 and 4.2 respectively with the two methods, and the reliability parameters meet the demands of norm of railway bridges. Consequently, the RPC is safety to be used in the railway bridges.
Properties of Recycled-Cement Produced from Waste Concrete
Authors: Ai Hong Mei , Wei Jing , Bai Jun ying , Lu Pu Guang
Published: February 2011

This research aims to find a new way of “turning trash into treasure” for the waste concrete. In the research, waste concrete was first ground, then, after analyzing its mineral composition, combined with some other ingredients according to the modulus of the cement clinker to become raw materials of cement. Mixed raw materials were made to be a thin cake, and then sent into high temperature furnace (HTF) to sinter for a certain period of time. Properties of cement, such as the compressive strength, required water of standard consistence and setting time were tested. The composition and microstructure of clinker were analyzed with X-ray diffraction (XRD) analysis and scanning electron microscope (SEM) analysis. The experimental results showed that the main mineral components of clinker are C3S, β-C2S, CA2, CA, C3A, C4AF, the compressive strength of the recycled-cement is approximately equal to P.O32.5, there exists an optimum sintering temperature for the recycled-cement clinker with a given mix ratio of raw materials and content of seed crystal added,, and this temperature is usually much lower than the temperature adopted wildly in the cement plants.
Microstructures and Hardness of Silver Alloys after Internal Oxidation Process
Authors: Wathanyu Kessaraporn , Rojananan Siriporn
Published: February 2011

The aim of this paper is to study the microstructures and hardness of silver alloys after internal oxidation process. The Ag-5Sn and Ag-5Cu alloys were prepared by melting and cast into ingots and then they were internal oxidized at the temperature range from 550 to 750°C, for 24 hours under oxidizing atmosphere by feeding oxygen gas with the pressure of 1 kg/cm2, gas flow rate 5 l/min and cooled in the furnace. The microstructures, Vickers microhardness and phase compositions were investigated. The results showed that the microstructures of the based metal revealed dendritic structure and they were transformed to equiaxed grains after internal oxidation. The internally oxidized layer of Ag-5Sn alloy is SnO2 with the hardness about 106-133 HV. The internally oxidized layer of Ag-5Cu alloy is CuO with the hardness about 65-73 HV.
Study on Interaction between Cerium and Arsenic
Authors: Zhang Jin Zhu , Dou Sheng Tao
Published: February 2011

The interaction among Cerium, Arsenic and Iron at high temperature were studied by means of electron probe microanalysis, optical microscopy and X-ray diffraction. The result shows that the binary compound CeAs is the main interaction product when the atomic ratio of Ce to As is 1:2. The eutectic compound Fe2As can be precipitated from ferrite with the temperature decreasing, and the gray phase in bright field might be a ternary compound Ce12Fe57.5As41.
Microstructure and Mechanical Properties of Hot-Rolled Low-Carbon Medium-Manganese TRIP Steels
Authors: Li Zhen , Zhao Ai Min , Tang Di , Li Ben Hai
Published: February 2011

Transformation Induced Plasicity (TRIP) steels have attracted a growing interest in recent years due to their high strength and ductility combination.An alternative alloy and processing concept has been studied to evaluate the feasibility of producing low-carbon medium-manganese TRIP Steels. Conventional hot-rolling, and batch annealing processes were simulated with three laboratory heats of varying manganese content. The steels were found to be fully hardenable with conventional hot-strip mill processing and subsequent batch annealing simulations produced significant retained austenite levels. The combination of the prior martensitic microstructure in the as-hot-rolled condition, and austenite created during annealing,resulted in remarkable combinations of strength and ductility. Optimum properties were found when samples were annealed at approximately 630°C. While this treatment maded the tensile strength to 800-1020 MPa, the total elongation increased to between 27 percent and 35 percent. UTS*TE products exceeding 30,000 MPa*% were observed, making these materials attractive for high strength, high ductility applications.
Characterization of Precipitates in Bend-Age-Formed 2124 Aluminium Alloy
Authors: Quan Li Wei , Zhao Gang , Liu Yue , Tian Ni , Peng Tao
Published: February 2011

The precipitates of bending-age-formed ternary Al-4.31Cu-1.51Mg alloy were studied with load of 6.05 kg aged at 190°C. Transmission electron microscopy and electron diffraction has been used to observe the microstructures of the bend-age-formed alloy. The results show that there is no preferential alignment of S phase or GPB zones in the alloys with load compared with that without load. It is interesting to find that the length of S phase is shorter in age-formed sample than that without load. Dislocations generated after loaded can provide enough nucleation sites for the nucleation and growth of S phase.
Pressureless Sintering and Properties Investigation of Silicon Nitride
Authors: Li Bin , Feng Yi , Liu Hui Qiang , Zhu Yan Fang , Yu Dong Bo , Zhang Xue Bin , Pan Xiao Bing , Tu Jing , Ouyang Xiao Ping , Cao Liang Zhi , Wu Hong Chun
Published: February 2011

Different grain size of starting powder was choosed and different sintering additives were used to fabricate Si3N4 ceramics by pressureless sintering. Samples’ relative density and mechanical properties including Vickers hardness, bending strength and fracture toughness were tested. Then XRD, SEM and EDS were carried out to identify phase and observe microstructure and fracture morphology. The result shows that high purity α phase Si3N4 powder of 5 μm is suitable for sintering and combination of 5 wt.% MgO +5 wt.% Y2O3 is most effective within six kinds of sintering aids.
Study on the Characterisation and Photocatalysis Reactivity of TiO2/Cu Composite Particles
Authors: Wang Bin , Yan Jun , Du Shi Guo , Cui Hai Ping
Published: February 2011

Nano-TiO2/Micron size Cu composite particles were prepared in ambient conditions by bio-inspired method. Observation by field emission scanning electronic microscope shows TiO2 particles of 3-5 nm covers on copper powder surfaces to form nanometer/micron composite particles. XPS analysis shows that the element C, O, Ti, Sn and Cu existed on the surfaces of the composite particles. UV-vis spectra show a red shift of the absorption edge and a significant increase of absorption intensity in the visible region. The degradation experiment taking methyl orange demonstrates the photocatalysis activation of powder with good body made. At the same time, the apparent kinetics model for degradation reaction was established.
Manufacture and Testing of a Moderate Size Integrated Marine Composite Propeller
Authors: He Xiao Dong , Zhang Hong Ming , Wang Rong Guo , Hong Yi
Published: February 2011

The composite material has high strength-to-weight, stiffness-to-weight ratios and it has the layer designing property to satisfy special mechanical requirement. Nowadays, the marine produce industry makes efforts to use composites for marine propeller to improve the hydrodynamic and structural performance. In this paper, the authors use FEA coupled CFD to design the layer sequence of composite propeller and develop ANSYS subroutine to simulate resin flow in the mould. The composite propeller is produced by RTM (resin transfer molding) and tested to measure the performance of composite propeller. Compared to the same size aluminum propeller, the composite propeller saves 39% weight and has less noise.
The Study of Existential State of Protein in Protein/Montmorillonite Complexes
Authors: Lv Ying Hai , Li Gui Jiang , Cui Li Qiang , Yan Hua Xiao , Zhou Shi Xue
Published: February 2011

The existential state of protein in complexes directly affects the performance and applications of the composite materials. The interlayer space changes of montmorillonite in the protein / montmorillonite (MMT) composite were identified by X-ray diffraction (XRD). And the interaction between protein and MMT were analyzed by Fourier transform infrared spectrometry (FT-IR) and UV/vis spectrophotometry. The loading amount of bovine serum albumin (BSA) onto MMT was calculated from the TG data. The types of adsorption isotherm of BSA onto montmorillonite were analyzed. From the above analysis, it can be concluded that the structure of proteins in the montmorillonite interlayers has been changed, and the hydrogen bond and Van der Waals force between the BSA molecules and montmorillonite crystal layers are intensified. The α-helix content of BSA molecules reduces while random coil increases. The protein shows a state of being squashed.
One-Step Synthesis of ZnS Nanocrystals with Graphite Sheaths from a Single-Source Precursor
Authors: Zhang Ke Jie , Zhou Hong Yan , Liu Xiao Heng , Wang Xin
Published: February 2011

Zinc sulfide (ZnS) nanocrystals with graphite sheaths were obtained from pyrolysis of bis(2-mercaptobenzothiazolato)-zinc (II) in nitrogen atmosphere at 400°C for 2 h without any additional sources. X-ray diffraction patterns showed that the ZnS crystals belonged to the hexagonal system. Transmission electron microscope studies revealed that ZnS/C nanocrystals were well-dispersed and had a diameter of 20~30 nm. The possible mechanism for the formation of the interesting well-dispersed microstructures was also proposed.The special structures of ZnS nanocrystals with graphite sheaths may have potential applications in nanoelectronics and photonics. This simple approach may be applied to the synthesis of other semi-conductor nanocrystals.
The Addition of Acid Treated Carbon Nanotube on the Tribological Properties of Carbon Fiber Reinforced UHMWPE Composite
Authors: Li Jian
Published: February 2011

Carbon fiber reinforced Ultra High Molecular Weight Polyethylene (CF/UHMWPE) composites have been filled with acid treated carbon nanotube to enhance the tribological properties. According to the modification, the friction and wear properties of composites have been greatly improved. XPS and SEM are used to examine the microscopic properties of resultant composites. The enhanced tribological properties are attributed to the acid treated CNT interlock, which improves the wetting between carbon fibers and resins.
Investigation of Microstructure and Property of the Fe3Al/Al2O3 Composites Fabricated by Mechanical Alloying Process and Plasma Active Sintering Process
Authors: Jiang Tao
Published: February 2011

The Fe3Al/Al2O3 composites were fabricated by plasma active sintering process. The Fe3Al intermetallics compounds powders were fabricated by mechanical alloying and heat treatment, then the Fe3Al powders and Al2O3 powders were mixed and the Fe3Al/Al2O3 composite powders were prepared, so the Fe3Al/Al2O3 composites were fabricated by plasma active sintering process at 1200°C for 5min under the pressure of 30MPa. The phase composition and microstructure of the Fe3Al intermetallics compounds powders produced by mechanical alloying and heat treatment were investigated. The phase composition, microstructure and mechanical property of the Fe3Al/Al2O3 composites sintered bulks were investigated. The XRD patterns results showed that there existed Fe3Al phase and Al2O3 phase in the sintered composites. The Fe3Al/Al2O3 composites sintered bulks exhibited the homogenous and compact microstructure, the Fe3Al particles were homogenously distributed in the Al2O3 matrix. The mean particles size of Fe3Al intermetallics was about 2-3μm and mean particles sizes of Al2O3 was about 2-3μm. The density and relative density of the Fe3Al/Al2O3 composites increased gradually with the increase of Fe3Al content. The fracture strength and fracture toughness of the Fe3Al/Al2O3 composites increased gradually with the increase of Fe3Al content. The elastic modulus and hardness(HRA) of Fe3Al/Al2O3 composites decreased gradually with the increase of Fe3Al content.
Mechanical and Tribological Properties of Phenol Formaldehyde Resin Reinforced with Nano-Silica
Authors: Yu Chuan Bai , Wei Chun
Published: February 2011

Reinforced phenol formaldehyde resin (PF) matrix nanocomposites with different nano-SiO2 were fabricated with two-roll compounding and compression molding technology. The mechanical and tribological behaviors of the reinforced composites were studied. The friction and wear experiments were tested on a constant speed machine (D-SM). The impact and flexural strength of nanocomposites were increased by the addition of various types of SiO2, but the flexural modulus was decreased. The effects of the addition of various types of SiO2 on tribological properties of the composites were explored in this study. The results showed that the coefficient of friction of the composites increased, while the wear rate values decreased at various temperatures. Microstructure of worn surface of the tested composites was observed by scanning electronic microscope (SEM) and the wear mechanism of the reinforced composites was studied.
Research on the Flexural Behaviour of Reinforced Concrete Beams Strengthened with CFRP
Authors: Wei Hua , Zhang Ji Ye , Zhu Da Wei , Peng Zhi Yuan , Wang Hai Jun
Published: February 2011

In order to clear the influence of carbon fiber reinforced polymer (CFRP) on the bearing capacity of reinforced concrete beams, tests of three reinforced concrete beams strengthened with CFRP are carried out. Experimental result shows that CFRP can effectively increase bearing capacity of flexural member, and can restrain the development of crack. Cracking load, yield load and ultimate load are significantly increased. At the same time numerical simulation is done; it is good agreement with experimental results.
Experimental Study on the Axial Behaviour of Cold-Formed Thin-Walled Steel Framing Wall Studs
Authors: Shi Yu , Zhou Xu Hong , Yuan Xiao Li , Nie Shao Feng
Published: February 2011

A full-scale experimental study on the axial behavior of cold-formed thin-walled steel framing wall studs is presented. The influence of parameters, including whether the studs are sheathed or not, sheathing materials, the screws spacing and the studs spacing, on the bearing capacity of studs under vertical compression is analyzed by the test. The test results of the six wall specimens show that: the load carrying capacity of a stud increases significantly when it is covered with sheathings; the ultimate load of the stud sheathed with fiber reinforced calcium silicate board(CSB) is about 18.8 percent higher than that sheathed with oriented strand board(OSB); when the wall frames are sheathed with OSB or plasterboard, the change of screws spacing has little effect on the bearing capacity, however, the bearing capacity of CSB-sheathed wall stud will fall when the screws spacing decreases from 300mm to 150mm; when the studs spacing increases, the bearing capacity of stud decreases slightly.
A Study of Test for Polyethylene / Modified Montmorillonite Nanocomposites
Authors: Chang Ming Kuen , Lin Jia Ying , Peng Yan Huei , You Jian Jhih , Wang Yu Ming
Published: February 2011

This study have used three different montmorillonite by anionic, nonionic and ammonium chloride modifier to prepare polyethylene / montmorillonite (MMT) nanocomposites. The kneading process doped modified MMT to polyethylene, according with ASTM D638 to proceed hot-press works, and ASTM D256 to determine the izod pendulum impact resistance of plastics specimen. Prepared nanocomposites continue proceed in tensile and impact testing, finally, we observed low-density polyethylene layered silicate nanocomposites properties were improved, also found that anion modified montmorillonite had significant reinforcement effect in tensile and impact testing.
Nonlinear Finite Element Analysis of Shearwalls with Various Types of Openings
Authors: Bae Baek Il , Choi Hyun Ki , Choi Chang Sik
Published: February 2011

The installation of new opening is necessary for remodeling project, house merging type. Current structural design code cannot provide the deterministic way for designing the shear walls with openings. So many engineers prefer to retrofit the perforated wall area for the structural safety. For the safe design of retroftitting, for the perforated structural walls, we carried out nonlinear finite element analysis to find the coupling effect of remaing walls. Specifically, many types of shapes were considered and various area of rectangular openings were analyzed. For the effective retrofitting, door shape and such area about 20% of wall is appropriate for retrofitting of reinforced concrete shearwalls.
The Effect on Scattering of SH-Wave in a Layered Half-Space with the Subsurface Circular Cavities
Authors: Chen Dong Ni , Qi Hui , Shi Yong
Published: February 2011

The scattering of SH-wave caused by the subsurface circular cavities in an elastic half-space covered with an elastic layer was discussed, which was based on the complex function method and wave functions expansion method. The solution of scattering of SH-wave was given by using circular boundary of large radius to approximate straight boundary of surface elastic layer. According to boundary conditions, we needed to solve the infinite linear algebraic equations with unknown coefficients in wave functions. Finally, the dynamic stress concentration factors around circular cavities were discussed in numerical examples.
The Dependence of the Corrosion Resistance of Ni-Cr-Mo-Cu Alloy to HCL Solution on the 4Cr/ (2Mo+Cu)
Authors: Li Hua Pan , Yang Rui Cheng
Published: February 2011

The kinetics of corrosion process on five Ni—Cr—Mo—Cu alloys designed by the empirical formula APF=4Cr/ (2Mo+Cu) in HCl solution have been investigated at the concentration range from 0.002mol/cm3 to 0.012 mol/cm3 and 20°C. It is developed that the kinetic parameters and the dependence of the corrosion resistance on the APF have discussed.
Experimental Study of the Steel Type Buckling Restrained Braces
Authors: Li Xiao Dong , Wang Xiu Li
Published: February 2011

In the domestic and international, experimental study for the Buckling Restrained Braces(BRBs) focuses on concrete type BRBs at present, but the type of BRB has a larger weight, and can change structure vibration characteristics, thus puts forward a new type BRB which is no longer filling in with concrete between kernel and outer components, meanwhile under monotonic loading and cycle repeated loading tests for the new BRBs, the experimental results show that the steel type BRB has good energy dissipation capacity, and can be applied to structure as passive control device.
Analysis and Countermeasures on Seismic Damages of Gas Pipeline Network in Wenchuan Earthquake
Authors: Wang Xiang Jian , Guo En Dong , Zhang Mei Jing
Published: February 2011

Based on seismic damage data of gas pipeline network, obtained through scientific investigation in 18 cities/counties, seismic damage appearances of gas pipeline which are made of different materials are summarized and compared, and their impacts on gas supply function are studied. Then the use status of pipeline of different materials and the reasons of causing damages are analyzed. And some earthquake resistant countermeasures are proposed to reduce the seismic damages.
Research on the Application of Periodic Truss-Core Structures to Structural Design of Machine Tool
Authors: Gao Dong Qiang , Mao Zhi Yun , Li Zhong Yan , Zhang Fei
Published: February 2011

The modal analysis and harmonic response analysis of the machine tool table with periodic truss-core structures are analyzed and calculated by finite element analysis software-ANSYS Workbench, then we get the finite element analysis results. After comparing the results with finite element analysis results of the original machine tool table, we come to the conclusion that the dynamic properties of the machine tool table with periodic truss-core structures are better than the original machine tool table’s. It makes a base for optimized design and remanufacturing.
The Microstructure and Properties of Restored WCP/Fe-C Composites
Authors: Song Yan Pei , Wang Hui Gai
Published: February 2011

A restored WCP/Fe-C composites is manufactured by centrifugal casting method. The microstructure and properties of the restored composites have been investigated by SEM, X-ray diffraction and properties tester. The results show that the distribution of WCP in the restored composites is even, Size of WCP is obviously reduced, and their volume fraction attained to about 70 vol.%. The mechanical properties and wear behavior of the restored composites are almost the same as those of the primary composites.
Research on Kitchen Waste Disposal Equipment and Technology
Authors: He Feng Qin , Wang Hua Lin , Qian Peng , Xu Su Ming
Published: February 2011

In this paper, we concluded that, in order to make good experiment effect, kitchen waste temperature rising rate should be at least 20°С / min. Taking in account experiment effect and experiment energy consumption, a pyrolysising technology is designed to change the kitchen waste's temperature rising rate in phases. At last, a set of mechanical equipment is designed to solve kitchen waste problem efficiently as well as produce bio-oil and other chemical raw materials. The result of prototype experiment shows the feasibility of the kitchen waste disposal equipment and technology.
Effect of Nitrogen on Mechanical Properties of 20MnSi at High Temperature
Authors: Yang Ji Chun , Liu Nan
Published: February 2011

The effect of nitrogen on the mechanical properties of 20MnSi steel at high temperature was investigated. Mechanical tensile test was conducted using a Gleeble-1500D. Microstructure and fractograms were analyzed using SEM and TEM. The results indicate that nitrogen in concentration of 0.4 ~ 0.6% improves the grain boundaries and grain refinement, and thus the strength and section shrinkage and plasticity of the steel. Further increase in concentration of nitrogen has little effect on section shrinkage.
Preparation and Characterisation of Amorphous Silica from Alkali Wastewater Produced in Manufacturing Process of ZrOCl2
Authors: Wang Bai Kun , Ding Hao , Zheng Yun Xing , Liang Ning
Published: February 2011

The amorphous silica was prepared from the alkali wastewater rich in Na2O•nSiO2 produced in manufacturing process of zirconium oxychloride (ZrOCl2). The composition and microstructure of amorphous silica were studied by X-ray diffraction, X-ray fluorescence and scanning electron microscope, respectively. The results showed that the amorphous silica was mainly composed of uncrystallized substance, and the silica content was 96.4%. Its whiteness was 97.5% and the particle size was between 100nm and 200nm without agglomeration. The specific surface area of the amorphous silica was 531.9 m2/g, and its pore volume and diameter were 0.945 cm3/g and 4.94 nm, respectively.