bluuebunny/crossref_metadata_2025 huggingface dataset:
Dielectric Relaxation in (Ba0.7Ca 0.3)TiO3-Ba(Zr0.2Ti 0.8)O3 Ceramics
Authors: Ju Shao Gong , Tang Xin Gui , Wu Jun Bo , Jiang Yan Ping , Liu Qiu Xiang
Published: July 2011

In this work, effect of low sintering temperature and time on the new lead-free perovskite (Ba0.7Ca0.3)TiO3-Ba(Zr0.2Ti0.8)O3 (BCZT) solid solution ceramics have been investigated. X-ray diffraction (XRD) was used to understand the phase transition of the BCZT during heating. The Curie temperature decreased nonlinearly 43 K in BCZT ceramics. Diffuse phase transitions were observed in BCZT ceramics and the Curie-Weiss exponent (CWE) was nearly 2. The dielectric permittivity versus temperature characteristics and the γ in the modified Curie-Weiss law, as a function of the dc bias field was obtained for BCZT ceramics. The fitting of parameters (Tm vs. f ) have close agreement with the data of Vogel-Fulcher’s relationship.
Hydrogen Storage Property of Ti45Zr35Ni17Cu3 Quasicrystal Powder
Authors: Liu Bao Zhong , Fan Yan Ping , Zhang Bao Qing , Zhang Zhi
Published: July 2011

Icosahedral quasicrystalline phase (I-phase) formed in a number of Ti-based alloys, and that the I-phase was well ordered and thermodynamically stable in the Ti-based alloy. Further, studies on the physical/chemical properties have received much attention. It was important from scientific and technological point to study the preparation and hydrogen storage property of the alloys. Recently we have prepared single I-phase Ti45Zr35Ni17Cu3 powder and investigated their hydrogen storage property. Here, we reviewed the research results and proposed the research of Ti/Zr-based I-phase as hydrogen storage material.
Finite Element Analysis on Stability for Elastic-Jumping Membrane
Authors: Wu Zhen Ting , Li Shun Jiang
Published: July 2011

In order to increase the designing precision and study the main factors influencing the stability of metal elastic-jumping membrane, a set of experimental equipments have been designed to test the stability of metal elastic-jumping membrane. The laws of influencing the stability of elastic-jumping membrane were studies by changing the thickness, high, radius etc structure parameter. It shows that the increasing of high and thickness can enhance the distortion rigidity of metal elastic-jumping membrane, result in the increase of critical load at losing stability; the increasing of diameter can reduce the distortion rigidity of metal elastic-jumping membrane, result in the decrease of critical load at losing stability. At the same time, the correctness of finite element model was confirmed, and the basis was established for finite element method applying in optimizing design of metal elastic-jumping membrane.
Experimental Investigations on Flexural Behavior of Sandwich Composite Panels
Authors: Chen Lu , Hou He Tao , Li Guo Qiang
Published: July 2011

Sandwich composite panel is a new developed building material applied in steel residential houses, but the theory and experiment of this panel is still limited. In order to study the influence of the boundary conditions and shear connector patterns on flexural behavior of the panels, two groups of panels were cast and tested. Failure modes of the test panels under the uniformed transverse load, load-deformation response, strains in two concrete wythes, crack loads and ultimate load-bearing capacity were recorded and analysed. Test results showed that different angles and distances of plane truss shear connectors affected the ultimate flexural strengths significantly. The strain curves of two concrete wythes revealed that the plane truss shear connectors of panels worked well to make the two wythes act as a solid slab. It is concluded that the sandwich composite panel is available in steel residential houses because of its economical and high flexural strength.
The Ac Impedance Characteristics of Soil with Different Water Content
Authors: Dong Xiao Qiang , Yang Guo Hui , Bai Xiao Hong , Lv Yong Kang
Published: July 2011

As an important and mature technology of researching material properties, ac impedance spectroscopy has successfully applied in many discipline except for soil research. Based on the experiments using TH2828A wide frequency LCR meter (from 50 to 106 Hz), the ac impedance characteristics with different water content of soil had been discussed. The results fully illustrate that the ac impedance is one of the basic property of soil,and the value of ac impedance parameter can be reflected the water content quantitatively. when using the fixed frequency to measure ac impedance of soil, it is most suitable as the frequency equals 104 Hz.The measure method of ac impedance have no effect to physical properties and internal structure of soil.
Numerical Simulation of Gas Distribution in COREX Shaft Furnace
Authors: Ying Wei Feng , Sun Ye , Luo Zhi Guo , Zou Zong Shu
Published: July 2011

Pre-reduction shaft furnace is a typical gas solid countercurrent reactor, in which complex transport phenomenon exists between gas-solid phases. In the present paper, a mathematical model has been developed to simulate the actual pressure field of the shaft furnace, the gas flow field and the distribution of gas flow backwards. The simulation results of the pressure field indicate that the pressure is distributed uniformly at the same height in the furnace. The results of gas flow field indicate that the velocity of gas flow near the side wall is larger than that in the inner part, and a gas dead zone exists at the lower part of the shaft furnace. Comparing the volume of gas flow through the every DRI downcomers, it can be drawn that the gas flow from DRI downcomers near the gas export side is higher than the other side.
Water Model Study on Circulation Rate Influenced by Snorkel, Nozzle and Blowing Parameters in RH Refining
Authors: Li Sheng Li , Ai Xin Gang , Wang Ning , Lv Nan
Published: July 2011

A water model of 1/4 linear scale for 210t RH has been established. RH circulation flow rate is measured by a velocimeter. The influences of lifting gas flow rate, snorkel inner diameter, injection depth and nozzle inner diameter on circulation rate were discussed. The dimension correlation has been calculated for the prediction of circulation rate. The results showed that the formula of circulation rate is 5.434×10-6G0.356·D1.254·d -0.106·H 0.821. The best nozzles inner diameter in terms of circulation rate was 3mm.
Effect of Microstructural Evolution on Mechanical Properties of 55NiCrMoV7 Steel
Authors: Fan Meng Ting , Sun Ming Yue , Li Dian Zhong
Published: July 2011

55NiCrMoV7 steel is extensively used as mould steel. However, how to obtain a product combined with both high strength and good toughness is still a problem in the heat treatment process. In current study, a series of 55NiCrMoV7 steel specimens were quenched with different cooling rates to obtain martensite, lower bainite and upper bainite, then tempered at 600°C, 620°C and 650°C, respectively. The micrographs show the evolution of microstructure with the variation of cooling rates and tempering temperature. Mechanical properties test has revealed that, 1) at the same tempering temperature, the tempered martensite has the highest strength and hardness, while the tempered lower bainite has the best impact toughness; 2) at the same ratio of yield strength to tensile strength (YS/TS), the ductility and toughness of martensite are better than that of bainite. Furthermore, fractographs of impact specimens show the ductile and brittle fracture behavior for martensite and upper bainite respectively.
A Review of Strength Models in Association with Pore Structure of Cement-Based Materials
Authors: Zhu Qiao , Jiang Lin Hua , Xu Jin Xia
Published: July 2011

In this article, some empirical and theoretical models accounting the relationship between the strength and pore structure of cement-based materials is reviewed and analyzed. From the literature review and analysis, it can be found that the total porosity can be singly used to characterize the relationship between compressive strength and pore structure, but can not be applied into describe the relationship between pore structure and tensile strength. Another major parameter of pore structure - pore size distribution, will have a major impact on strength; the relationship between pore structure and tensile strength is for most models of cement paste, without the consideration of aggregate, and the application of the model must comply with the relevant assumptions. The research on the relationship between the tensile strength of concrete is still at a preliminary stage, requiring more theoretical and experimental study.
Study on the Influence of Oxygen Content on Fatigue Life of Bearing Steel Using Statistics of Extreme Values
Authors: Chung Ho Hua , Hsu Chin Chuan
Published: July 2011

In this study, scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) are used to measure the inclusion size and identify the inclusion type respectively. The evaluated maximum nonmetallic inclusion size of bearing steel has been obtained using statistics of extreme values (SEV), and the influence of oxygen content on the maximum nonmetallic inclusion size and the fatigue life of bearing steel have also been discussed. By adopting the criterion of return period (T) at 200, the serial analyses show that the predicted inclusion size formax is proportional to the oxygen content of steel, but the relation between fatigue life and oxygen content of steel is inverse proportion. This results from the defragment of hard inclusion during rolling process, and the decrease of concentration of stress around the inclusion.
Influence of Heat Treatment on Low-Cycle Fatigue Behavior of AZ61 Magnesium Alloy
Authors: Yin Shu Ying , Chen Li Jia , Wang Xin
Published: July 2011

In order to identify the influence of solid solution, aging and solid solution plus aging treatments on the low-cycle fatigue behavior of the extruded AZ61 magnesium alloy, the low-cycle fatigue tests were performed at room temperature for the extruded AZ61 magnesium alloy with different treating states. The results indicate that the cyclic stress response behavior of the extruded AZ61 magnesium alloy exhibits both cyclic strain hardening and stability. The solid solution, aging and solid solution plus aging treatments tend to decrease the cyclic deformation resistance of the extruded AZ61 alloy in most conditions. The solid solution treatment can enhance the fatigue lives of the extruded AZ61 alloy at medium total strain amplitudes. In addition, the aging treatment can prolong the low-cycle fatigue lives of the AZ61 alloy at most total strain amplitudes, while the case for the solid solution plus aging treatment is just contrary. For the extruded AZ61 alloy with different treating states, a linear relationship between cyclic stress amplitude and plastic strain amplitude is noted.
Research on Fireproofing and Insulation System of Polyurethane Foam and Moulding Board with Glazed-Hollow-Bead Mortar
Authors: Yue Jian Wei , Sun Xin Sheng , Li Lian Dong , Huang Xiao Liang
Published: July 2011

In this paper, a new insulation system of polyurethane foam and moulding board with glazed-hollow-bead mortar is designed. According to the principle of the temperature gradient and the spreading and releasing stress in different layers, the fire prevention and aging resistance performance of polystyrene board in external insulation system are improved. Performances of fireproofing and insulation motor of different ingredients, such as glazed hollow bead, fly ash, polymer emulsion powder, quicklime and fiber were tested in the lab, and the reasonable mix ratio of the mortar was obtained. Moulding board of glazed-hollow-bead mortar was deigned and manufactured. To quickly construct and improve quality of the new insulation system, fixed moulding board system was manufactured, board of glazed-hollow mortar and fixed board system were gained.
A Study on Tensile Mechanical Properties of Bamboo Plywood
Authors: Han Jian , Gao Xi Tao
Published: July 2011

The tensile mechanical properties of bamboo mat and curtain plywood（for short bamboo plywood）were studied through “electrometric method”. It was proved that in the range of elastic deformation，the Poisson′s ratio and the elastic modulus of the bamboo plywood were not constant. The Poisson′s ratio of the bamboo plywood decreased nonlinearly with the load increase that Poisson′s ratio decreased markedly when the load was less than 1kN，and decreased gently when more than 1kN.The tensile elastic modulus of the bamboo plywood also increased nonlinearly with the load increase that the tensile modulus of elasticity increased drastically when the load was less than 800N，and increased less when exceeded 800N. In the process of loading，the tensile deformation、the tensile stress and strain all increased linearly with the load increase，and the tensile stress and strain both were linearly relevant to tensile deformation.
Research on Effect of Ion Nitriding Temperature on Wear Resistance of 40Cr Steel
Authors: Pang Guo Xing , Li Zhong Lei , Chen Zhi Yong , Wang Yan Jie
Published: July 2011

The main purpose of this paper is to research on the different ion nitriding temperatures of 40Cr effect on the surface hardness, wear resistance of the workpiece. With series of experiment and test of micro-hardness, ring-block wear, metallographic observation, to select the optimization temperature for the ion nitriding process of 40Cr steel.
Fatigue Analysis of the Pipeline Robot's Swing Rod
Authors: He Fan , Fu Jia Xing , Huang Zhi Long
Published: July 2011

Put forward and develop a pipeline cleaning robot. Relying on finite element analysis software ANSYS，establishing finite element model of pipeline robot swinging rod with the solid92 as the basic unit，it was found that the swing rod of the pipeline robot was the weak link by a large number of on-site experiments. After analysis the fatigue properties of pipeline robot's swing rod，compared with the results of its static analysis and evaluation of failure mode of pipe robot's swing rod，reasonable proposals are put forward for the follow-up study of the pipeline robot.
Determination of Fracture Toughness and K-R Curve for 2524-T3 Aluminum Alloy
Authors: Xie Wei , Tu Shao Wei , Huang Qi Qing , Li Ya Zhi
Published: July 2011

In the present work, the resistance to crack extension of 2524-T3 aluminum alloy under Mode I loading was studied by using the middle-cracked tension M (T) specimens. The curve, plane-stress fracture toughness and apparent plane-stress fracture toughness were calculated by test data. The average value of measured fracture toughness at room temperature was 161 MPam1/2. The results and conclusions can be referred in airplane skin design.
Study on Fatigue Crack Growth Model of Attachment Lug Subjected to Oblique Pin-Load
Authors: Wu Li Ming , He Yu Ting , Zhang Hai Wei , Cui Rong Hong , Du Jin Qiang , Ding Hua
Published: July 2011

The finite element model of a straight attachment lug subjected to an oblique loading less than 45 degrees is built by using the finite element software ANSYS, a cosine pin-bearing pressure distribution is applied on the hole of lug as a boundary condition. The stress intensity factor (SIF) expression for the straight attachment lug with a single through-the-thickness crack, which is subjected an oblique pin-load less than 45 degrees, is determined by studying on the influence law of dimensionless crack length (a/R1)，ratio of outer radius to inside radius (R2/R1), inside radius (R1) and pin-load angle (β) on the SIFs values. The expression is validated by contrasting with the ANSYS results and the data of residual strength test. The stress intensity factor’s amplitude (ΔK) are calculated by the SIF equation to get the values of the Paris constants. The fatigue crack growth model of attachment lug subjected to oblique pin-load is established, offering an analytical as well as experimental method for assessing and designing damage tolerant attachment lugs.
Low Cycle Fatigue Behaviour of GX12CrMoVNbN9 -1 Cast Steel at Room Temperature
Authors: Golański Grzegorz , Werner Krzysztof , Mroziński Stanisław
Published: July 2011

The report treats of the low cycle fatigue (LCF) behaviour of GX12CrMoVNbN9-1 (GP91) cast steel after heat treatment (1040°C/12h/oil + 760°C/12h/air + 750°C/8h/furnace). Fatigue tests were carried out at room temperature for five levels of the controlled total strain amplitude εac = 0.25, 0.30, 0.35, 0.50 and 0.60 %. The research performed within the scope of LCF has shown in general that the investigated cast steel was subject to strong cyclic weakening, revealing no stabilization period at the same time. At the final stage of fatigue there was quick weakening of the material which proceeded till its destruction. The growth of amplitude εac resulted in reducing the number of cycles till the destruction stage.
Experimental Studies on J-Integral of Welded Buried High-Density Polyethylene Pipes
Authors: Qi Fang Juan , Li Jian , Yang Zhi Juan , Fang Min
Published: July 2011

Investigation shows that one of the failure modes of HDPE pipe is the crack slowly grows across the thick direction and leads to failure at last. So that it is very important to study the resistance to crack initiation properties of HDPE pipe and its butt-fusion welded joint. The J-integral is applied to character the fracture initiation of a tough polymer for which the concept of linear elastic fracture mechanics (LEFM) are inapplicable for reasonably sized specimen due to extensive plasticity. In this paper, the multiple specimen resistance curve technique was employed for J-integral. The normal single side notched three-point bend (3PB) specimen was used to study the characteristic fracture parameter of high-density polyethylene pipe and its butt-fusion joints at different temperature. Testing results show that values of characteristic fracture parameter are affected by the welding process and experimental temperature respectively. The toughness value of HDPE butt-fusion joint is lowered than that of HDPE pipe. With the temperature decreasing, the toughness value of HDPE pipe and Butt-fusion welded joint decrease. And the same time testing results also show that J-integral can describe the fracture character of high-density polyethylene exactly. Testing results can be used for the engineering design and failure analysis of HDPE pipe.
Effect of Chlorine on Combustion Process of Pulverized Coal in Tuyere Zone
Authors: Hu Bin Sheng , Gui Yong Liang , Guo Hua Lou , Song Chun Yan
Published: July 2011

The relation between chlorine and combustion process of pulverized coal in tuyere zone is affected by the existence form of chorine in coal. The combustion process of pulverized coal in tuyere zone is restrained by chorine of coal when the existence form of chorine is chloride created by Cl- and metal cation. The combustion process of pulverized coal in tuyere zone is improved by chorine of coal if chorine existents with the form of combination of HCl and nitrogen functional groups of coal macromolecules. Under the combustion conditions of tuyere zone in blast furnace, the distribution ratio of chlorine in unburned pulverized coal and blast furnace gas is approximately 60% and 40%, respectively.
Study on CH4 Adsorption onto the Surfaces of Perovskite ABO3 ( A=La, Ba; B=Zr, Co, Ce) by Density Functional Theory
Authors: Gao Zi Shu , An Hua , Lv Li , Hou Li Chun , Han Hui , Wang Xiao Jing
Published: July 2011

The adsorption of CH4onto the surfaces of perovskite-type catalysts ABO3( A=La, Ba; B=Zr, Co, Ce) was investigated by a density functional theory based on the first-principles in this paper. The absorption mechanism was derived by population and electronic states analysis on the basis of the electronic and surface structure calculations. For A=Ba and B=Zr, the frontier energy state was found to the key factor in controlling the adsorption behavior of CH4absorbed on (001) surfaces, which is mainly contributed by oxygen and B-site ions. The most favorite adsorption site for CH4was located at B-sites of perovskite catalysts ABO3, where the A-site ions adjust the charge of B-site ions and moreover affect the CH4adsorption.
Study on Injecting Forming Technology of Railway Locomotive Bearing Retainer
Authors: Liu Han Wu , Dong Rui Hua , Feng Fan
Published: July 2011

According to the superiority performance, the applications of engineering plastics tend to be widely used day by day in the field of railway transport. The research of locomotive-bearing retainer is an important technology that should be resolved proposed by the Ministry of Railways’ report on the outline of the Eleventh Five-Year Plan. In this paper, the characteristics of each process of the injection molding in the different stage, the main technology parameters, and the influence of the primary process parameters on the part manufacture quality were systematically analyzed. And the modern injecting forming software and new technology were applied to analyze the injecting forming technology, to design the mould structure, to forecast the possible defects and breakdown in the process of injecting forming with the thematically design and the CAE technology. The study results can be extended to the design of other similar parts, which has very strong engineering applications significance.
Dynamic Compressive Behavior of Granite under Active Confinement
Authors: Chen Gang , Kuang Yu Chun , Huang Xi Cheng , Xu Ai Min
Published: July 2011

The behaviour of geologic material such as granite under impact loading is involved in the study of safety requirements of structures in extreme simulations such as earthquakes, accidental impacts or explosions. Based on incident pulse shaping design of quasi-brittle material for dynamic tests, experiments on granite under uniaxial and active confinement conditions are conducted with the split Hopkinson pressure bar(SHPB). By adding the soft material mass as the pulse shaper, the stress uniformity in the specimens before fracture is ensured and the fluctuation of test data due to incident stress pulse is avoid. The experimental results show that the compressive strength is increasing with the strain rate and the confined pressure. The fragments size decreases with the strain rate. The research method and conclusion could be used to analyze the dynamic behavior of the other brittle materials.
Effects of Mg Addition on Thickness of Galvalume Coating: A First-Principles Study
Authors: Wu Guang Xin , Zhang Jie Yu , Li Qian
Published: July 2011

The presence of Mg addition in bath has been shown to improve the corrosion resistance of the hot-dip Al-Zn alloy coating while adhesion of coating degrades. And the underlying mechanism of the additive effects was not very clear. In this work, first-principles method has been used to investigate the effect of Mg addition on thickness of Galvalume coating. The optimized geometric configurations, total energy and electronic charge distributions for the Mg substitution in Fe2Al5 and FeAl3 phases were obtained. And results indicated that the most favorable sites for Mg substitution in both Fe2Al5 and FeAl3 phases are Al positions. Bonding energy and charge density results show that the addition Mg could not form Mg-Al bond and has little effect on the thickness of alloy layer.
Mechanical Test on Pipe Collapse under External Pressure
Authors: Yong Kang
Published: July 2011

Many factors result in pipe collapses under certain external pressure. The relations among them have been studied by the pipe collapse tests. This pepper focused on the test analyses of steel pipe collapse resistance. Those include a pipe collapse pressure test under external pressure and illustrate both test and preparing theoretical analysis, and results of the collapse pressure with the effects on the tendency of ovality. In addition to various pipe collapse data and mechanical test methods, this study will offer a summary of the findings for the further intention of theories researches.
Determination of Exciting Power and Saturation Characteristics for Dual Laminated Core Models
Authors: Zhao Zhi Gang , Liu Fu Gui , Wang You Hua
Published: July 2011

Dual laminated core models for determining exciting power (or/and specific total iron loss) and over saturation characteristics occurred at joints and silicon steel sheet was proposed and prototyped. Calculation method of exciting power at joints of transformer was presented. The saturation characteristics of laminated silicon steel sheets was obtained and analyzed. The model also can be used to investigate the relevant electromagnetic behavior of laminated core in detail.
The Equipment on High Sensitive Test of Infrared Directional Emissivity of Materials
Authors: Zhang Li Yong , Liang Yu Kun
Published: July 2011

This paper introduces an approach of novel principle to measure the directional emissivity of material surfaces direct. The value of the infrared directional emissivity is obtained by comparing the surface spectral emissivity of testing samples to a blackbody reference. Weak signals are measured with pyroelectric detector by optical modulation and phase-locked amplified technologies. Our experiment is implemented with stainless steel in circumstance of 20 - 300°C, the testing sample is 8µm- 14μm. Compare to the reference and the calibration value without a cooling process, combined uncertainty is less than 0.04, and the result is satisfied.
Microwave Joining 95-Al2O3 Ceramics Used Al-Si Alloy as Interlayer
Authors: Zhao Ying Na , Liu Jia Chen , Xu Hai , Zhang Wen Li
Published: July 2011

Absorber-microwave material Al-Si alloy powder was used as interlayer to join the 95-Al2O3ceramics. The behaviors curves of time-temperature for Al-Si alloy interlayer and 95-Al2O3ceramics at different microwave power were researched. The interlayer morphology of the joints region was characterized by SEM and the element and phase components were analyzed by EDX and XRD. The results indicated that the loact heating around 95-Al2O3ceramics could be achieved by microwave sintering. The joint interfaces of Al-Si/95-Al2O3formed at microwave 2KW/20min→0KW and the joint mechanism of 95-Al2O3ceramics was transient liquid phase diffusion bond.
Microwave Assisted Solid State Reaction Synthesis of Complex Amino Acid Complexes of Mn (Ⅱ)
Authors: Liang Bo Lin , Zhang Na , Zhou Min Jie
Published: July 2011

Complex amino acid complexes of manganese ions were synthesized using the chelation technology under microwave irradiation. The influences of amount of water, reaction time, microwave power and the molar ration of complex amino acid and manganese on the yield of the synthesized compounds were investigated. Results suggest that optimal synthesis conditions are amount of water, 4 mL, irradiation time, 4 min, microwave power, 500 W, and the molar ration of reactant, 2:1, and the yield of the synthesized compounds was 67.42%.
Microstructure Research of Magnesium with Laser Surface Cladding by Al-Si Alloy
Authors: Yang Sheng , Wan Xian Qing
Published: July 2011

Using laser clads magnesium surface with Al-Si eutectic powder, analyzing the organization and composition of the cladding layer with scanning electron microscopy and EDS. The results show that the cladding layer mainly composed of β (Mg17Al12) phase, α (Mg) + β (Mg17Al12) eutectic, α(Mg) solid solution, Mg2Si phase composition, and cladding layer and the substrate combined well, pores and cracks weren,t found. Laser heat treatment of the cladding layer, then the bulky Mg2Si phase was blown, small blocks were distributed in the grain boundary and improve the performance of the cladding layer.
Patterning of ITO on Glass with Two-Step Using Excimer Laser and Wet Chemical Re-Etching
Authors: Shen Xue Fei , Chen Tao , Liu Ning
Published: July 2011

ITO electrode patterns were fabricated using excimer laser direct-writing technique. The influence of the process parameters (the excimer laser fluence and the stage velocity) on the micromachining quality (the etching depth and ridge height of the edge ) of ITO patterns were experimentally studied. In this paper, the effect of laser fluence and the speed of working platform on the fabrication quality were discussed. The lower laser fluence and suitable platform speed will be very helpful to improve the edge quality of patterning of ITO. However, the recast ridge at the edge also was shown. Use of 39% solution of hydrochloric acid made it possible to further minimize the recast ridge at the edges.
Toughing of ZrAlN Film through Superlattice Design
Authors: Du Jun , Zhu Xiao Ying , Cai Zhi Hai , Zhang Ping
Published: July 2011

Two kinds of magnetron sputtering ZrAlN films containing 23%atAl were deposited. The first was multicomponent ZrAlN film, the second was structure gradient and mulilayer film, named superlattice ZrAlN film. The microstructure was studied by FESEM, TEM , XRD, its mechanical properties were evaluated by nano-indentation method. The fracture toughness of films were determined from the length of ‘radial cracks’ on the applied diamond identer load 1.96N. the results show that, multicomponent ZrAlN film has hardness value of 35GPa, fracutre toughness value of 1.97MPa·m-0.5; while superlattice ZrAlN film has coresponding value of 40.1GPa and 3.17MPa·m-0.5. TEM image illustrates the superlattice ZrAlN film period is 2.5nm, nanoidentation test shows superlattice film has higher elastic recovery parameter and lower plastic work.
Characteristic of Laser Texturing Surface Aided with Abbott Curve
Authors: Dai Jin Yue , Zhang Yan Hu , Wang Zu Quan , Hua Xi Jun , Fu Yong Hong
Published: July 2011

Laser surface texturing improved tribological property is regarded as an optimistic method. However, many technological parameters have crisscross effects on surface topographies, the complexity of relations between variables devoted to a tough way to express functions accurately. Meanwhile, enough basic tents of theory can be borrowed to interruption for obtained the expectation in the process of micro-texturing on critical surfaces. And thus pumping current and number of laser pulse were chosen and studied for improving the surface topographies realized by Nd3+: YAG laser, assisting a better expectation of reduction of abrasive grains. The single-factor method was exerted in the process of analysis, one international 3D-morphology meter and its accessory codes were adopted before the analysis of constitutive influence from pumping current and pulse times in given duration on characteristic parameters of texturing surface, the results are shown in figures by Abbott curve and characteristic parameters which were compared in the literate.
Transverse Superplastic Deformation of Laser Welded Ti-6Al-4V Sheet
Authors: Cheng Dong Hai , Zhou Ye Ping , Wei Qiang , Chen Yi Ping , Hu De An
Published: July 2011

Uni-axial hot tensile tests were used to investigate the transverse superplastic deformation of laser welded Ti-6Al-4V sheet. Microstructures of the weld bead before and after superplastic deformation were observed by optical microscope. The maximal deformation of 46% was obtained on weld joint at strain rate of 10−2s−1 and temperature of 1173K. A coefficient K was introduced to evaluate the non-uniform deformation of weld joint. After superplastic deformation the microstructure of weld bead transformed into lamellas from original acicular structure.
Investigation of Grease Lubrication Effects on the Fretting Wear Behavior of Ball Bearings
Authors: Wang Si Ming , Gao Hong Li , Xu Ming Heng
Published: July 2011

In order to investigate the effects of grease lubrication on fretting wear of ball bearings, a series of fretting wear tests were performed under the dry condition and grease lubrication by a self-made fretting wear rig. And tests were completed at different angles, load and number of cycles. The results showed that the grease lubrication can effectively reduce fretting wear; reduction effects increase as the oscillation amplitude increases and load decreases; oxidation in fretting wear decreases as number of cycles increases under grease lubrication; and wear mechanism is diffrent at under different lubrication conditions.
A Two-Disk Test Rig for Researching the Damage Behavior of Rolling/Sliding Contact Surfaces under Extreme Conditions
Authors: Peng Bo , Wang Li Qin , Fan Shou Xiao , Zheng De Zhi , Gu Le
Published: July 2011

A two-disk test rig researching surface damage and ultimate performance of rolling-sliding tribo-parts in extreme conditions is designed. Variable speed (rolling speed up to 83.6m/s, sliding speed up to 16.4m/s) of the rolling/sliding contact are input by motor spindle and regulated with gear. Variable load (Hertzian contact up to 4GPa) is applied with hydraulic cylinder. High temperature (~+300°C) and cryogenic environment(liquid nitrogen) is implemented by changing the lubricant condition. Thermal-stress analysis with ANSYS shows that the temperature and stress of the tester body is reasonable. As the signals judging failure, such parameters as temperature and vibration of the supporting bearing, power consumption of the main spindle, temperature of the tribo-parts surface are monitored in real time. Kingview, PLC, VB and MATLAB software are employed in the online monitoring system to collect data automatically. Types of tribo-parts were tested in the test rig, getting their ultimate performance and the effect of each parameter on surface damage.
A Shakedown Limit under Hertz Contact Pressure
Authors: Shiau Jim S.
Published: July 2011

In his "Contact Mechanics" book, Professor K. L. Johnson described an analytical lower bound shakedown approach to predict the shakedown load limit under repeated Hertz moving surface loads. Based on Bleich-Melan shakedown theorem, this problem will be revisited in this paper using finite element techniques and mathematical programming.
Key Problems in Study on Fretting Fatigue of Aluminum Alloy
Authors: Xu Li , Chen Yue Liang , Yi Lin , Luo Hao
Published: July 2011

Fretting fatigue usually occurs in the structure of aeronautics and astronautics, and accelerates expansion of cracks about the surface of structures. Because of the complexity of the surrounding of aircrafts, the corrosion of aluminum alloy structures is great serious, so the research about the influence of corrosion to fretting fatigue is very important, also the study of multi-site fretting is very significant.
Analytical Model of a Simple Supported Beam with Variable Section Subjected by a Moving Load
Authors: Zhang Jun , Zhou Zi Wen , Xv Jin , Ni Xiao Lu
Published: July 2011

The variable section influence on the vibration of a simple supported beam under the action of a moving constant concentrated force is investigated in this work. The technique is based on analytical approach with the assumed model method and the numerical approach of Newmark method. Comparisons with the results between vary-section beam and constant-section one indicate that it is a wise approach to economizing materials and lightening the load of gravity by applying vary-section beam on the condition that the maximum stress cannot change dramatically.
Decentralized Semi-Global Stabilization of Large-Scale Nonlinear Systems with Mixed-Order Nonlinearities
Authors: Ye Hui , Zhai Jun Yong
Published: July 2011

This paper considers the problem of semi-global decentralized output feedback control of large-scale systems with subsystems interconnected by nonlinearities which are functions of the measurable and immeasurable. The distinguishing factor of this paper is that the nonlinearities are allowed to have both higher-order and lower-order terms, to which the existing design schemes are inapplicable. Simulation results are given to demonstrate the validity of the proposed method.
Analysis on High-Speed Sampling Device with Big Interior Force
Authors: Feng Jing , Zhang Jian Li , Ma Yong Tao
Published: July 2011

For the biggest top steel ring, the sampling device characteristic seriously influences on precision sampling. The simulation model was built in AMESim and certificated by experiments. Through simulation, the external load and the car interior are important factors in speed stability. It derived the calculation formula on external load and compared with experimental results. Under the load limit, the velocity will stable with load change. Above the load limit, the velocity will fluctuate violently. An overweight car prolongs the starting time and aggravates the braking vibration. Under a reasonable design specification, 300kg is optimum. These conclusions had been applied in this newly designed device effectively.
Research on Topology Optimization Method for Continuum Structure under Geometric Constraints
Authors: Ren Li , Yang Rui , Zhang Wen Xiao
Published: July 2011

A new topology optimization model with holes’ geometric constraints for continuum structure is presented. It is solved by an evolutionary optimization method based on interval relaxation, in which the problem is divided into two subproblems of topology optimization process and size/shape optimization process. The optimal topology of structure can be found gradually by introducing interval relaxation factor to adjust holes’ size constraints, delete noneffective holes and by generating new holes based on the sensitivity analysis of objective function. Interior penalty-function method is employed as an optimization technique for the size/shape optimization of the structure corresponding to the topology. When the holes’ size bounds are the actual values, the optimal solution is the smallest objective function structure in the various topologies. Thus realizes the holes’ geometric size and location design, topology design and layout design together. The optimization results of example shows the method proposed is of good effectiveness and engineering applicability.
The Analysis of Radial Magnetic Bearing’s Magnetic Field in Active Magnetic Bearing Electric Spindle Unit
Authors: Liao Ping , Ma Su Yang , Wu Guo Qing , Mao Jing Feng , Jiang An Dong
Published: July 2011

Introduced the working principle of active magnetic bearing unit and took the electric spindle with 5.5kW for example, finite element analysis of the magnetic fields of radical magnetic bearing was analyzed through finite element analysis by ANSYS software to find out the variation of magnetic field distribution and affecting factors. Analysis results showed that radical magnetic bearing had small leakage magnetic field, the principal axis’ maximum offset from the ideal center line was 0.0025mm and the principal axis had superior radical running accuracy when the circularity of supporting journal on principal axis was 0.003mm, the unilateral air-gap value was 0.3mm while the principal axis suspended normally and the inside track’ circularity of magnetic pole was 0.007mm. It can meet the working requirements of precision machine tool. The research results provided theoretical basis for structural optimization of the active magnetic bearing unit.
Research on the Local Upwind DQ-Lagrange Method for Solving the Flow Field in Labyrinth Seal
Authors: Sun Dan , Yang Jian Gang , Guo Rui , Cao Hao , Zhang Wan Fu
Published: July 2011

The paper sets up an upwind local differential quadrature-Lagrange interpolation (DQ-Lagrange) method for solving the flow field in the interlocking labyrinth seal. The implementation of the Dirichlet boundary condition and the Neumann boundary condition is improved. The paper analyzes the influence of support domain size, the implementation of boundary condition and the upwind scheme on the accuracy of the calculation. Numerical simulation result shows that the high order Lagrange interpolation may cause numerical oscillation and the local differential quadrature method is recommended. The upwind support domain can improve the accuracy of the calculation. Solution accuracy may be better in case of that the velocity support domain is larger than the pressure support domain.
TiC Particle Reinforced Reactive Plasma Cladding Composite Coating by the Precursor Carbonization-Composition Process
Authors: Liu Jun Bo , Wang Li Mei , Jiang Jun Sheng , Cao Guang Ming
Published: July 2011

Fe-Cr-Ti-C composite powder was prepared by precursor carbonization-composition process using the mixture of ferrotitanium, chromium, iron powders and precursor sucrose as raw materials. In situ synthesized TiC particle reinforced composite coating was fabricated on substrate of Q235 steel by reactive plasma cladding process using Fe-Cr-Ti-C composite powder. Microstructure of the coating was observed by scanning electron microscope (SEM), the phases in the coating were determined by X-ray diffraction (XRD), and the wear resistance of the composite coating was evaluated under dry sliding wear test conditions at room temperature. Results indicate that the composite coating consists of in-situ the reinforcing TiC carbide, (Cr,Fe)7C3 eutectics and austenitic, and is metallurgically bonded to the Q235 steel substrate. TiC carbide in the composite coating showed the gradient distribution. TiC particles present granular in the fusion zone and central zone, and present dendritic in the surface of the composite coating. Hardness of the coating from surface to fusion zone is little difference, the average hardness of the coating is about HV0.2750, is as 3.2 times as the base. The wear mass loss of Q235 base material is 12 times as that of the composite coating.
Numerical Simulation of Body Heat Transfer Coefficient Test of a Railway Vehicle
Authors: Zang Jian Bin , Cai Ming Wei , Gao Nai Ping
Published: July 2011

The body heat transfer coefficient of a railway vehicle is an essential parameter for designing vehicle. The proposed method in this paper could be used to simulate the test conditions of body heat transfer coefficient of a railway vehicle. The simulated object was a middle of high speed train and the numerical simulation was two-dimensional due to the limitation of RAM capacity of PC computers. Simulation results with five different meshing showed body heat transfer coefficient was affected greatly by the amount of grids. Existence of thermal bridge would increase body heat transfer coefficient significantly, which was concluded by the simulation of two models. Three typical cross sections of a middle were used for simulation of the body heat transfer coefficient and the weighted mean value was 1.30 W/m2•K. The difference was only 7% compared with the actual test value of 1.215 W/m2•K, which indicated the advantage of this method.
A Method of Double-Side Displacment-Rotation Flat-Lapping with Solid Abrasives
Authors: Yan Wen , Huang Yu Mei , Gao Feng , Liu Yao
Published: July 2011

A method of double-side displacement-rotation flat-lapping with solid abrasives is proposed and a CNC machine tool is developed in this document. By analyzing the lapping principle and the structural characteristic of common solid abrasives flat-lapping method, the deficiencies of this method are indicated. The new method changes the motion pattern of workpiece in principle, the relative position between the workpiece and abrasive disks (lapping tools) are changed while the workpiece rotates. Therefore those deficiencies are made up radically, the lapping trace and velocity distribution of the relative motion between the workpiece and abrasive disks are more reasonable, the stress and wear states of isolating plate are improved as well. Finally, the driving moment and the speed of workpiece rotary are analyzed, and the relative velocity between the abrasive disks and workpiece is researched.
Physico-Chemical Characters of Pyrolysis Oil Obtained from Sewage Sludge
Authors: Ji Ai Min , Li Hai Ying , Li Zi Qiang , Liu Hong Ya , Gao Ying
Published: July 2011

Pyrolysis oil derived from sewage sludge is considered as one of the substitute of crude in the world confronting energy shortage. Before the utilization of pyrolysis oil in industry, comprehensive investigation of its physico-chemical characters is needed. Through detailed analyze of its fuel properties and other characters including metal content, solid content and stability, the pyrolysis could not used as No. 4 fuel before improving its fuel characters, decreasing its metal and solid content, and increasing its stability. The detailed analyze of the pyrolysis oil could provide basic data for the process and use of it in future.
Production of Si-Al-Fe Alloy with Carbothermal Reduction of Coal Fly Ash
Authors: Ma Guo Jun , Jin Yi Biao , Yang Da Bin
Published: July 2011

In this study, production of Si-Al-Fe alloy with coal fly ash and bauxite as the major raw materials in the induction furnace at high temperatures were studied. The results show that carbothermal reduction of mixture of coal fly ash, bauxite, hematite, silica and CaF2 in the induction furnace can produce Si-Al-Fe alloy, and it can therefore improve the utilization value of fly ash and reduce its pollution to the environment. The reduced alloy phase mainly contains ~23% Si, ~19% Al and ~52% Fe, and small amounts of P and S. The main phases of alloy are Al0.5Fe3Si0.5, FeSi, SiC, Si5C3, FeC, and TiC.
Research of the Excellent Engineers’ Quality Training
Authors: Liu Chang Ming
Published: July 2011

This article utilizes the synthetic analysis method to propose the proposition of excellent engineers’ quality training. Excellent engineers are those who are outstanding and better than general engineers. The paper discusses the background and the practical demand of excellent engineers’ developing, it also expounds the basic qualities that excellent engineers should possess and clarifies the trainning of excellent engineers is the higher project education’s sacred mission. The conclusion is: it should take the way of co-production and learning, and the government departments should provide support in politics, economy, law and so on, then it will help to improve the enterprises’ initiative to participate in engineering talents’s training.
Uncertainty Analysis of Thermal Protection by Microencapsulated Phase Change Micro/Nanoparticles during Hyperthermia
Authors: Lv Yong Gang , Zou Yang , Yang Li
Published: July 2011

Uncertainties for thermal protection efficacy caused by deviations of the values of phase change materials (PCMs) properties (including conductivity, heat capacity, thermal conductivity, latent heat and phase transition temperature) were studied based on our previous study. Our results suggested that the radius of the micro/nano PCM particle, and the upper and lower phase transition temperatures of the PCM should be carefully measured before performing thermal protection by PCMs during hyperthermia. The results will further help us to enlarge the application of clinical hyperthermia in cancer treatment and optimize the treatment protocol of thermal protection by PCMs.
Study on the Control Technology of Piezoelectric Transducer Assembly
Authors: Zhang Yun Dian , Hong Wei Wei
Published: July 2011

The author analyzes the problems existing in the traditional assembly system and puts forward a new method based on the motor control. This paper introduces the design and development of the automatic assembly system of ultrasonic cleaning transducer. In the system we use photoelectric isolation technology to solve the problems that driving circuit interference control chip while using a chip control many motors and this simplify the assembly system structure, reduce the cost of the assembly system and improve the assembly system automation and precision.
Exploration on Methods of Making PAFC Using Coal Gangue
Authors: Wang Xian Li , Shi Peng Hui , Wu Jun Feng , Zhu Pan Min
Published: July 2011

The paper expounded the impact of coal gangues on environment. Also it deals with the feasibility of making polymeric aluminum and ferric chloride (PAFC) using coal gangue. Through orthogonal test, the paper explores such factors as roasting temperature, roasting time, hydrochloric acid concentration, reaction temperature and grain size influence on the making process, and give the best operation conditions: roasting temperature is 700°C, roasting time is 1.5～3.5h, hydrochloric acid concentration is 25%～30%, reaction temperature is 120°C and grain size is 60 mesh. At last, the qualities of products are analyzed and the conclusion is given: it is feasible to make PAFC from coal gangue and it should be popularized.