bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Hot Extrusion and Heat Treatment on Mechanical Properties and Microstructures of AZ91 Magnesium Alloy
Authors: Tan Ming , Liu Zhao Ming , Quan Gao Feng
Published: September 2012

The effects of heat treatment on the microstructure, tensile property and fracture behavior of as-extruded AZ91 magnesium alloy were studied by OM and SEM. The results show that the grain of as-cast AZ91 alloy is refined by extruding and dynamic recrystallization, and the mechanical properties increase obviously. The ductility is significantly enhanced after solution treatment of the as-extruded AZ91 alloy, tensile strength is almost the same before and hardness is significantly reduced after solution treatment and artificial aging treatment. The tensile strength reduced and the ductility is significantly enhanced of as-extruded AZ91 magnesium alloy after annealing processes. The fracture surface of as-extruded AZ91 magnesium alloy has the mixture of ductile and brittle characteristic. But after T6 or annealing treatment, its dimple number increases evidently.
Ni-TiN Composite Coatings Prepared by Ultrasonic-Magnetic-Electrodeposition
Authors: Ma Chun Yang , Ma Chun Hua , Yang Zhan Fa
Published: September 2012

Ni-TiN; Composite coating; Ultrasonic-magnetic-electrodeposition Abstract: In this paper, Ni-TiN composite coatings were prepared by ultrasonic-magnetic- electrodeposition. The optimum parameters were achieved by experiments and analysis. The structure of Ni-TiN coatings was observed using HRTEM. And the wear resistance was tested by the grinding machine. The results illuminated that the optimum technical parameters prepared Ni-TiN coatings are TiN particle concentration 4g/L, ultrasonic power 200W, magnetic intensity 0.6T, current density 5A/dm2, temperature of the electrolyte 50°C, pH 4.5. The HRTEM showed that the diameter of Ni grains and TiN particle in Ni-TiN coatings were about 60nm and less than 40nm, respectively.
Study of the Synthesis and Photocatalytic Properties of Iron-Doped Titania Nanocrystallines at Room Temperature
Authors: Wei Zhi Hao , Zhong Min , Deng Yin
Published: September 2012

Iron-doped titania (TiO2) nanocrystalline were prepared by sol-gel method at room temperature. The samples were characterized by using transmission electron microscope, X-ray diffractometer and ultaviolet-visible spectrophotometer. X-ray diffraction shows that iron-doped titania have the titania anatase and brookite structure, and the more iron doped in, the less titania brookite structure. When the doping content of 10at% iron, the titania brookite structure disappear absolutely. Transmission electron microscopy shows that with the increase of iron-doping from 0.00 to 0.25, the average size of the grains decrease from 5.7nm to 4.3nm. And samples have higher crystallinity. Using UV-visible spectrophotometer to measure its photocatalytic properties the results show that it has the highest rate of 60% photocatalytic degradation when it is absorbed in methylorange in two hours. With the increase of iron-doping from 0.00 to 0.25, the more iron doped in, the higher photocatalytic properties.
CO2 Erosion of the Ni-TiN Nanocoatings Prepared by Electrodeposition
Authors: Ma Chun Yang , Ma Chun Hua , Yin Yi Fang
Published: September 2012

CO2 erosion; Ni-TiN nanocoating; electrodeposition Abstract. Ni-TiN nanocoatings were successfully fabricated by pluse electrodeposition (PED) on the surface of 20 steel. Microstructures of the coatings were investigated by XRD, SEM, and HRTEM. In the CO2 erosion test, both 20 steel and Ni-TiN nanocoatings were evaluated using the autoclave. The XRD and HRTEM results demonstrated that the Ni-TiN nanocoatings were consisted of Ni phase and TiN phase. And the average diameter of Ni grains and TiN particles were approximately 52 nm and 30 nm, respectively. The CO2 erosion experimental results indicated that the Ni-TiN nanocoatings showed better corrosion resistance than 20 steel. And CO2 pressure had great effect on the erosion characteristic of Ni-TiN nanocoatings.
The Effect of SiC Content on Pressureless Sintered Si2ON2-SiC Ceramic
Authors: Tang Zhu Xing , Tan Hui Hui , Zhang He , Xu Ke Zhou , Zhang Ying
Published: September 2012

The Si¬2ON2-SiC ceramic was fabricated by pressureless sintering method. In this paper we researched the effect of SiC content (50%, 70% and 90%) on the performance of silicon oxynitride bonded silicon carbide ceramics. Through testing and analyzing the SEM, XRD, density and porosity of the final silicon oxynitride bonded silicon carbide ceramic samples, the results show that: changes in SiC content not only affect the bulk density of the composites but also affect the phase composition and the microstructure of fracture surface. The most compactness experimental product is sintered at1500°C containing 50wt% SiC.
Study on Correlate Qualitatively the Deposition Conditions with the Morphology of the Nanocomposite Films
Authors: Jiang Yong Jun
Published: September 2012

In the Nb–Si–N films, Si content (CSi) was varied in each series by changing the power applied on the Si target, whereas the power on the Nb target was kept constant. The microstructure of the coatings was examined by XRD and in cross-section by transmission electron microscopy (TEM). Depending on TS and pN2, the deposition rate showed significant variations from 0.04 to 0.18 nm/s. The correlation between film morphology (preferential orientation of crystallites, grain size, column dimensions, thickness of the SiNx layer covering NbN crystallites) and the deposition conditions (power applied on Si target, temperature, nitrogen partial pressure and deposition rate) provides useful information for optimizing the deposition process.
Research on Prediction Method of Alloy Element Yield in Smelting Stage of Iron and Steel Product Based on Improved Support Vector Regression
Authors: Meng Qiu Nan , Guo Guang Qin , Shi Wen Jing , Nan Zhi Ying
Published: September 2012

In the actual production of iron and steel enterprises, alloy element yield is difficult to predict because it changes with different materials, processes, etc. Then planning weights of raw materials can't be calculated accurately so as to influence raw material cost planning control. Taking raw material attributes, process parameters, and etc. of smelting stage as the influence factors, the prediction model of alloy element yield is built. In order to increase the model’s prediction accuracy, parameter optimization method for support vector regression (SVR) based on ant colony algorithm (ACO) is designed, which optimizes punish parameter, nuclear parameter and sensitive coefficient. The performance of the SVR algorithm with optimized parameters is compared with the grid search algorithm to verify that the former’s performance and efficiency are better. The prediction method of alloy element yield based on the above improved support vector regression is built, whose regression and generalization performance are better compare with BP neural network, so that the relationship between influence factors and the alloy element yield is established. It can predict alloy element yield accurately according to the actual process and provide methods for realizing lean production in iron and steel enterprises.
The Oxide Inclusion and Heat-Affected-Zone Toughness for Low Carbon Bridge Steels
Authors: Li Shu Rui , Wang Xue Min , Zheng Chao Chao , He Xin Lai
Published: September 2012

By welding thermo-simulation and actual welding practices, the microstructure and properties of low carbon bridge steels has been studied with the aid of optical microscope, scanning electron microscope. The experimental results show that by the oxide introducing melting technology there are many complex inclusions composed of oxide containing Ti and MnS. These inclusions are spherical and they are distributed homogeneously. During the welding thermo-simulation these oxide inclusions will promote the nucleation of acicular ferrite and make the microstructure in HAZ finer. Therefore the toughness in HAZ is good whether in welding thermo-simulation even if the heat input reaches to 200kJ/cm. In actual welding the heat input is 88kJ/cm and the low temperature impact energy still can reach 110J.
Mechanisms of Grains Refining in Adiabatic Shear Band of Titanium Alloy
Authors: Sun Kun , Xu Yuan , Liu Jin Hao
Published: September 2012

Dynamic shearing high strain-rate experiments on three types of titanium alloy have been carried out by using a modified split Hopkinson bar. Microstructure and mechanism for grains refining in adiabatic shear band formed under the condition of high strain-rate were investigated by means of optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). It is shown that the mechanisms for grains refining in adiabatic shear band of titanium alloy mostly consist of three sorts. They are the mechanism of breakdown of elongated grains which due to action of dislocations,and the mechanism of rupture of twins and the mechanism of dynamic recrystallization, respectively. The mechanism of dynamic recrystallization is the universal one for grains refining in adiabatic shear band of titanium alloy. The formation of refining grains is usually a result of combined action of several sorts of mechanisms.
Effect of Annealing on the Magnetostatic and Microwave Electromagnetic Properties of Glass-Coated Fe-Rich Microwires
Authors: Di Yong Jiang , Wang Jun , Chen Deng Ming , Jia Bi , Jiang Jian Jun
Published: September 2012

Glass-coated FeCuNbVSiB microwires was annealed in the temperature range of 380 °C to 600 °C. The microstructures and magnetostatic properties of the glass-coated microwires were characterized by X–ray diffraction (XRD), Vibrating Sample Magnetometer (VSM) respectively. Relative complex permeability and complex permittivity was measured by transmission/reflection (T/R) coaxial line method in the frequency range of 2-18 GHz for as-casted and annealed Fe-rich microwires samples. The measured results show that the coercive field of the Fe-rich microwires decrease to 1.54 Oe at 470 °C, and then increase rapidly with the increasing of the annealing temperature. The coercive field and saturation field of the microwire samples increased abruptly with the outgrowth of the Fe-B hard magnetic phase in the Fe-rich microwire samples. The imaginary part of permeability and the natural ferromagnetic resonance frequency decrease for the thermal treatment below 470 °C, and then increase with the annealing temperature up to 530 °C. The change of magnetostatic and microwave electromagnetic properties of the microwires samples with the annealing process come from the change of the anisotropy caused by the internal stress.
Friction and Wear Performances of Magnesium Alloy against Steel under Lubrication of Rapeseed Oil with N-Containing Additive
Authors: Fang Jian Hua , Wang Jiu , Wu Jiang , Chen Bo Shui , Dong Ling
Published: September 2012

A N-containing additive, amide type modified rapeseed oil (named as NRO), was prepared by chemical modification of rapeseed oil and characterized by infrared spectrum The friction and wear performances of AZ91D magnesium alloy against GCr15 bearing steel under the lubrication of rapeseed oil formulated with NRO were evaluated on a SRV tribotester. The topographies and the chemical species of the worn surfaces of magnesium alloy were analyzed by a scanning electron microscope (SEM) and an X-ray photoelectron spectroscope (XPS), respectively. The results indicated that the friction and wear of the magnesium alloy—steel tribomates could be effectively reduced by formulating NRO into rapeseed oil lubricant. The friction coefficients and the wear volumes of magnesium alloy decreased with increasing contents of NRO. The surface lubricated with NRO-doped rapeseed oil was characterized by less wear as compared with that lubricated with neat rapeseed oil. The enhanced anti-wear and friction-reducing abilities of rapeseed oil by NRO in the lubrication of magnesium alloy against steel were ascribed to the formation of a composite boundary lubrication film due to the strong adsorption of NRO and rapeseed oil onto the lubricated surfaces and their tribochemical reactions with magnesium alloy.
Investigation on the Properties of Supercritical CO2 Fluid and its Heat Transfer Characteristics
Authors: Yang Zhen Jiang , Yang Jun Lan
Published: September 2012

The obvious characteristics of transcritical CO2 cycle are that the heat rejection process takes place in the supercritical region. The thermophysical properties of supercritical CO2 change dramatically with the temperature and pressure near the critical region, which results in the momentum and energy exchange and buoyant force change in the heat flux direction, so it should be treated as “variable properties”. According to the characteristics of CO2 specific heat, the correlation of the pseudocritical temperature is obtained and the pseudocritical region is defined. The heat transfer features of CO2 under supercritical pressure are different from those of the conventional refrigerants. In order to compare the heat transfer performance of supercritical CO2 fluid and the conventional refrigerants, the contrast investigation on the heat transfer treatment principle, the heat transfer mechanism and the thermophysical properties are mainly presented in this paper.
Status of the Development and Application of Oil Sand
Authors: Chen Jia He
Published: September 2012

Oil and natural gas are important energy and chemical raw materials, its resources are gradually reduced. With the rapid development of the global economy, the conventional oil resources can’t meet the rapid growth of oil demand, people began turning to unconventional oil resources, one of which is the oil sands. Oil sands is unconventional oil resources, if its proven reserves are converted into oil, it will be much larger than the world's proven oil reserves. Canadian oil sands reserves stand ahead in the world, followed by the former Soviet Union, Venezuela, the United States and China. However, due to its special properties, different mining and processing technology, and higher mining costs compared with conventional oil, the research of oil sands makes slow progress. At present, due to the rising of world oil price, oil sands mining technology have attracted more and more attention, and have developed a lot.
Influence of Calcined Temperature and Sintered Technology on the Properties of NBT-KBT-BT Lead-Free Piezoelectric Ceramics
Authors: Huang Xin You , Gao Chun Hua , Chen Zhi Gang
Published: September 2012

The influence of calcined temperature and sintered technology on the properties of 0.85 （ Na0.5Bi0.5 ） TiO3-0.144(K0.5Bi0.5)TiO3-0.006BaTiO3(NBT-KBT-BT) lead-free piezoelectric ceramics was investigated by conventional solid state method, and the relationship between calcined temperature, sintered technology and properties of NBT-KBT-BT lead-free piezoelectric ceramics was obtained. The influence of calcined temperature on the material phase was investigated by X-ray diffraction(XRD), the influence of sintered technology on the microstructure of ceramics was investigated by scanning electron microscopy (SEM). Results show that there are impurity phase Na0.5Bi4.5Ti4O15 and main crystal phase （Na0.5Bi0.5）TiO3 while calcined temperature is 830-870°C, the impurity phase decreases while calcined temperature increases, there is pure （Na0.5Bi0.5）TiO3 phase while calcined temperature is more than 890°C. The density of ceramics first increases and then decreases, the crystal grain size first increases and then decreases while sintered temperature increases. The crystal grain size increases straight while soaking time prolonges. When calcined temperature is 890°C, sintered temperature is 1160°C and soaking time is 2 h, the comprehensive properties is good which the dielectric constant(εr) is 1055, the piezoelectric constant(d33) is 144 pC/N, the dielectric loss(tanδ) is 4.0%.
Microstructure and Mechanical Properties in QT-Treated 9Ni Steel
Authors: Su Hang , Zhao Xi Qing , Pan Tao , Lei Xiao Rong , Wang Qing Feng
Published: September 2012

Microstructure and mechanical properties in QT-Treated 9Ni steel were investigated. The detail microstructures were observed by optical microscope (OM) and transmission electron microscope (TEM). The volume fraction of austenite was estimated by XRD. Tensile test at room temperature and Charpy-V-Notch (CVN) impact test at -196°C were carried out. The results showed that the microstructure of QT-treated 9%Ni steel was composed of tempered martensite and reversed austenite. The brittle cementite was absorbed gradually by the increasing reversed austenite as the tempering temperature increased. The optimum tempering temperature range was 560°C~580°C. The reversed austenite could improve the cryogenic toughness of 9Ni steel through the combination of the scavenging effect and the TRIP effect.
Composite Repair and Reinforcement Technology for Oil and Gas Pipeline and its Development Trend
Authors: Wang Jin You , Wang Xiu Yun , Lu Min Xu
Published: September 2012

Pipeline repair and reinforcement technology can generally be categorized into three main types: Welding, Clamp, Fiber Composite. Fiber Composite Repair recently undergoes fast development because it does not require heat or welding and can be directly applied to high pressure transmission pipeline. This article summarizes Fiber Composite Repair technology and its mechanism, also compares the application characteristics of Glass Fiber, Carbon Fiber and Basalt Fiber composites and finally concludes broad application prospects of Carbon Fiber Composite in pipeline repair and reinforcement.
Effects of Modified Graphite on Thermal Properties of Modified Graphite/CA-MA/PMMA Composite for Latent Heat Thermal Energy Storage
Authors: Meng Duo
Published: September 2012

The aim of this work is to prepare a kind of polymer-based form-stable PCM with a higher thermal conductivity. Graphite powders modified by titanate coupling agent were chosen as the thermal conductivity enhancer. The modified graphite(MG) and capric acid(CA)-myristic acid(MA) eutectic as thermal absorbing material were blended into the poly-methyl methacrylate (PMMA) serving as supportive matrix during the bulk-polymerization process of MMA. The composite PCMs with different MG mass fraction (2%, 5%, 7%, 10% and 15%) were characterized by SEM, DSC technique, volume expansibility measurement and mechanical test. Thermal conductivities of the composites were measured by transient hot-wire method. The results indicate that the MG/CA-MA/PMMA composites keep the good thermal storage performance while the thermal expansibility becomes weaker. Thermal conductivity of the composite PCM has been enhanced significantly.
Gasification Characteristics of a Novel Domestic Straw Gasifier
Authors: Liu Xin , Tang Zhi Guo , Ma Pei Yong , Hu Xian Guo
Published: September 2012

In this paper, A novel domestic straw gasifier, with an inner U-shaped tube in which porous ceramics was placed to crack the tar carried by producer gas, is put forward. From experiments results, it can be investigated that producer gas with low tar content and high heat value could be obtained.
Fabrication of Aluminum-Containing Silicon Carbide Fibers from Electrospinning
Authors: Chen Yong , Yu Yu Xi , San Hai Sheng , Yang Da Xiang
Published: September 2012

Aluminum-containing silicon carbide (SiC/Al) fibers were fabricated by electrospinning a polyaluminocarbosilane (PACS) solution followed by the pyrolysis of the electrospun fibers at 1200 oC in a nitrogen atmosphere after air-curing at 200 oC. The optimum electrospinning conditions were a 0.9 g/mL PACS solution with 20%DMF/20%THF/60% toluene composition, a 20 kV spinning voltage, a 2 mL/h injection speed and a 10 cm receiving distance. The obtained SiC/Al fibers have a diameter in the range of 0.7~1.5 m.
Influence of the Ratio of ZnO/SnO2 on the Photocatalytic Property of ZnO/SnO2 Nanometer Powder
Authors: Huang Xin You , Gao Chun Hua , Chen Zhi Gang
Published: September 2012

ZnO/SnO2 nanocomposite powder were prepared by coprecipitation method with SnCl4·5H2O, ZnNO3·6H2O, HCl, NaOH as raw materials. Influence of different mol ratio of ZnO/SnO2 on the photocatalytic activity of ZnO/SnO2 nanocomposite powder was researched by the degradation of methyl orange as a reaction model. The particle size and dispersion of ZnO/SnO2 powder was characterized by transmission electron microscope(TEM). The results show that the photocatalytic activity of ZnO/SnO2 nanocomposite powder was increased significantly when compounded by SnO2, the photoactivating activity of ZnO/SnO2 powder starts increasing and then decreasing when the ratio of ZnO/SnO2 decreases. When ZnO:SnO2 is the ratio of 4:1(mol ratio)，the photocatalytic activity of ZnO/SnO2 nanocomposite powder is the best and the degradation rate of methyl orange is 42.09% when visible light illuminate for 225 minutes, particle size is 20-30 nanometer and dispersion is good.
A Novel Experimental Method and its Numerical Simulation for the Bi-Stable Anti-Symmetric Composite Shell
Authors: Wu He Long , Zhang Zheng , Bao Yu Mei , Wu Hua Ping
Published: September 2012

Based on the discussion of the current research methods about the bi-stable composite shell, a novel experimental method named four points bending loading is presented to provide driving moments to snap an anti-symmetric bi-stable composite shell from one stable state to another. Then, the feasibility of this new method was confirmed using the finite element analysis software ABAQUS. Finally, the future work, which is to construct an experimental platform according the four points bending loading method, is pointed out.
Effect of Screw Assembly on the Properties of Glass Fiber-Reinforced Nylon-66 Composite
Authors: Jiang Zhao Yin , He Ya Dong , Xin Chun Ling , Li Gang
Published: September 2012

The fiber brakeage in compounding glass fiber-reinforced nylon-66 with different screw assemblies of the co-rotating twin screw extruder was studied, and comparative analysis of five different screw assemblies was made. The result shows that proper screw assembly could improve the residual fiber length and the mechanical property of the composite effectively
Ultrasound Continuous Treatment on Interface of Carbon Fiber/Phenolic Resin Composites
Authors: Liu Bing , Liu Li , Huang Yu Dong
Published: September 2012

Ultrasound treating system is used to improve, continuously and on-line, the wettability between carbon fiber and phenolic resin during the process of impregnation. The cavitation and the agitation action in the liquid aroused by ultrasound improve the adsorption, diffusion and wetting of phenolic resin on the surface of carbon fiber, enhance the mechanical properties and finally utilize fully the outstanding property of carbon fiber reinforced composites. Effects of ultrasound on natural properties of prepregs and surface morphology of carbon fiber/phenolic resin composites are studied. The difference of composite surface between not treated and after treated by ultrasound is watched by SEM.
The Design and Analysis of Polymer Cosmetic Micro-Needle
Authors: Hedra Abrahem.M.M. , Cai Heng Zhi , Xue Ling , Hao Zhen Feng , Wang Xin Liang , Zhang Ya Jun
Published: September 2012

At present, most of cosmetic micro-needle in the market is made of biomedical stainless steels, but the processing technology is complicated and the piece-production cost is high. Micro injection molding technology can make the complicated polymer micro-needle in one cycle with the help of the rich experience accumulated in this area. And the method is suitable for mass production. This paper introduces the design of a new type of cosmetic micro-needle with polymer, its number simulation with injection molding software mold flow and the strength simulation.
Three-Dimensional Braided Composites Detection Method Based on Improved Chaotic Neural Network
Authors: Sun Bao Shan , Wan Zhen Kai
Published: September 2012

Three-dimensional braided composite materials for the use occurred during the fracture, deformation and other injury problems, a distributed Bragg grating sensor applied to detection of parts in health status. With three-dimensional braided composite weaving, research on the mechanical properties of small parts, sensors embedded in the sensor signal processing easy way. Embedded in three-dimensional composite parts of the sensor network signal processing method, the rapid implementation of distributed signal processing and the structure of large parts of the distributed monitoring.
Synthesis of Aluminum Nitride Powder by Carbothermal Reduction
Authors: Xu Ke Zhou , Tang Zhu Xing , Zhang Ying , Tan Hui Hui , Zhang He
Published: September 2012

In this paper, aluminum nitride powder was prepared by carbothermal reduction. Alumina and carbon black powder were used as the starting material to synthesize aluminum nitride powder in a nitrogen atmosphere at 1500~1900°C. The experimental data, SEM photographs and XRD analysis showed that higher temperature was conducive to the increase in conversion ratio of Al2O3, the growth of particles, and improving the degree of crystallization and purity of AlN. But it made the particles’ size larger with poor dispersion.
Synthesis of β-Sialon Ceramics Using Si, Al and Al2O3 Powders
Authors: Zhang He , Tang Zhu Xing , Tan Hui Hui , Xu Ke Zhou , Zhang Ying , Li Guo Chang
Published: September 2012

Single-phase β-Sialon ceramic compacts with z=2 have been synthesized by reaction-bonded sintering using Si, Al and Al2O3 as raw materials. After post-sintering at 1550°C for 2h, only β-Sialon ceramic compacts with z=2 was obtained. When the temperature up to 1650°C and 1750°C, the decomposition reaction of samples was occurred.
The Properties of Modified Adobe Materials with Desulfurization Waste
Authors: Jia Xing Wen , Zhang Ya Jie , Qian Jue Shi
Published: September 2012

As a modifier, desulfurization waste can improve the performance of traditional adobe materials. The results show that it was possible effectively to modify properties of adobe materials by means of DHG and DFA. When the molding pressure is 15 MPa, the compressive strength of modified adobe materials arrived at 7.5MPa at 28 days. Moreover, modified adobe materials remain a better volume stability and water resistance observed in the drying shrinkage (0.6mm/m) and softness coefficient (0.52), respectively.
Effects of Growth Rates on Directionally Solidified Microstructure of Al-Ni-Y Ternary Alloy
Authors: Xu Rui
Published: September 2012

The directional solidification of the ternary Al alloy with composition of 2.6 at%Ni, 0.9 at%Y and 96.5 at% Al was carried out under the temperature gradient of 5 K/mm and the droping velocities of 0.5 mm/min, 1 mm/min, 5 mm/min, 10 mm/min, and 25 mm/min. The microstructure of the Al-Ni-Y ternary alloy was also analyzed by X-ray diffraction and optical microscope. The experimental results show that the microstructures of the Al-Ni-Y ternary alloy are consisted of ª-Al2, Al3Ni and Y4Ni6Al23phase when the alloy was directionally solidified in all directionally solidified rates in the experiments. No primary -Al can be found in the sample with directionally solidified rate of 0.5 mm/min. When the rates higher than 1 mm/min, the primary ª-Al can be observed. The microstructure of the directionally solidified alloy becomes finer and the primary ª-Al is smaller gradually with the increasing of growth velocities when the dropping rate of directional solidification is higher than 5 min/min. Two eutectic structures, Y4Ni6Al23andª-Al eutectic and Al3Ni and ª-Al eutectic, can be found when the dropping rate is higher than 10 mm/min.
Study of Iron Oxide in Hardener on Properties of Phosphate No-Bake Binder Foundry Sand or Core
Authors: Zhang You Shou , Hu Tu , Huang Jin , Xia Lu
Published: September 2012

By adding iron oxide to the unitary magnesium oxide, a compound curing agent is made. Studies showed that the tensile strength of phosphate no-baked sand was increased more than 60% by adding the compound curing agent to hardener and the store stability of phosphate no-baked sand was also improved. Changing the percentage of the iron oxide, it showed that the addition quantity of iron oxide and the property of sand wasn't linearity. The highest tensile strength was obtained by 20% content of iron oxide based on total hardener. But a better sand store stability at room temperature and normal humidity air was gained by 30% iron oxide. Putting this no-baked sand under high humidity (more than 90%) condition for 24 hours, the no-baked sand become flexible and the tensile strength is decreased.
Milling Tool Wear Condition Monitoring Based on Extension Theory
Authors: Wu Dong Min , Shen Ming
Published: September 2012

The method of mill tool wear condition evaluation based on the extension theory is put forward by the paper. Through researching, the author firstly designs mill tool wear monitoring system which can acquire milling force signal, AE signal, vibration signal and main motor power signal. Based on the matter-element of classics, joint domain and evaluation, and deducting the dependent functions, at last the objective and reasonable evaluation results are got. It is proved that the extension theory is the valid and reliable in evaluating the mill tool wear condition.
Analysis on Torsional Vibration of Low-Speed Diesel
Authors: Liu Zhong Ming , Liu Kai , Hou Xiao Qin
Published: September 2012

In order to analysis the torsional vibration of crankshaft train in various assembly conditions, a 5S60 diesel model is presented based on AVL-EXCITE. A torsional vibration model is established by using the lumped mass method. And the deformation of main bearing is calculated under the bolt preload and outbreak of combustion. In addition to rated conditions, a state of one cylinder out of service is considered in this project. According to the calculation of the critical speed, torsion modes, angular displacement, shear stress in crankpin and minimum oil film thickness, the torsional vibration characteristics are analyzed. The study revealed that this system performs in good condition and the resonance is not obvious.
Experimental Study on Active Vibration Control of a Gear Pair System Based on FxLMS Algorithm
Authors: Wang Lei , Li Yi Nong , Zhang Feng , Ding Qing Zhong
Published: September 2012

To treat gear pair vibration due to internal excitation, an active internal gearbox structure near the gear pair is developed based on an active shaft transverse vibration control concept in the effort to tackle the gear excitation problem more directly. A controller of the FxLMS algorithm combined with frequency estimation technique is designed. And it is evaluated based on the experimental setup of the active gearbox vibration control system in contrast to fuzzy-PD controller. The experimental results show that 9.94dB attenuation in the gearbox housing vibration response can be achieved at the first gear mesh frequency by FxLMS controller, but only 5.62dB attenuation by fuzzy-PD controller. Besides, the insufficient effect at 210.8Hz and 216.2Hz is caused by typical out-of-band overshoot.
The Three-Dimensional Dynamics for Toroidal Drive
Authors: Xu Li Zhong , Li Jin Liang , Li Ya Jun
Published: September 2012

In this paper, a model to simulate the dynamic behavior of the toroidal drive is developed. The three-dimensional dynamic model includes all six rigid body motions of the stator, worm, rotor and the planets. Using the model, the natural frequencies and vibration modes of the drive system are investigated. The vibration modes are classified into single modes and coupled modes. The single modes include planet mode, worm mode and stator mode. The vibration and frequency characteristics of different modes are obtained. The relation between modes and half cone angle of the planet tooth is discussed. The relation between vibrations and bearing stiffness is also discussed. When the bearing stiffness is about 10 times of the mesh stiffness, some vibration displacements of the drive system are quite small and can be neglected. Meanwhile, the dynamic equations for the drive system can be simplified.
Simulation of Surface Contact Process and Study of Friction and Wear Mechanisms
Authors: Fan Yu Jin , Li Zhe Kun , Liu Jian Xiong
Published: September 2012

In the paper the process of a rigid particle penetrating into thermal refining steel and sliding on the surface is simulated by finite element method, the plough effect of sliding on contact surface and the adhesion effect of adhering to contact surface have be investigated. The apparent plastic flow and the material deposit are observed in the contact region, and the surface shape and the contact pressure distribution are obviously changed, the result of simulation is that surface deformation, contact pressure and friction shearing stress of contact surface depend on material mechanical properties, surface geometrical shapes and surface contact states. The mechanisms of plough effect and adhesion effect in friction are also studied, it is show that the mechanisms of adhesion effect and plough effect are different, plough effect is mainly crushing the surface layer in contact region, affected by material mechanical properties and surface shapes, and adhesion effect is mainly tearing the surface layer, affected by surface contact states.
A Special Solution of Spatial Straightness for Four Datapoints
Authors: Meng Fan Wu , Xu Chun Guang , Hao Juan
Published: September 2012

Assessment of spatial straightness error is one of the most difficult tasks in form error evaluation, especially when the minimum zone three-dimensional (3D) straightness is decided by four datapoints. This paper develops a solution that can transform the non-linear system into a linear system. To solve the linear indeterminate system of equations, a method of factor fixed is proposed. Given adequate initial conditions, this solution will be the exact solution. The effectiveness and efficiency of the novel approach are illustrated by two examples.
Verification on Indirect Inverse Substructuring Method for Coupling Dynamic Stiffness Identification of a Mechanical Assembly
Authors: Lu Guang Qing , Pang Dong Mei , Dong Kui , Zhou Bin , Li Xian Neng
Published: September 2012

Indirect inverse substructuring dynamic analysis has been developed recently by the author of this paper and provides a new simple approach to determine the coupling dynamic stiffness, which is one of important characteristics estimating dynamic quality of a mechanical product assembly. Based on a physical model consisting of “8-mass plus 16-spring and 8-damping” elements, this paper provides a set of validation on the completeness and effectiveness of the approach. Experimental verification is also carried out by use of eighty testing data of frequency response functions (FRFs).
Preparation of Super Hydrophobic Surfaces by the Stainless Steel Wire Mesh as Templates
Authors: Zhuang Jian , Du Meng Meng , Cai Heng Zhi , Zhang Ya Jun , Wu Da Ming
Published: September 2012

A facile method for manufacturing super hydrophobic surfaces is presented using the stainless steel wire mesh as templates. The rough surfaces of polymers including polycarbonate, polypropylene and PMMA are prepared with hot embossing on different specifications of stainless steel wire mesh. Scanning electron microscopy (SEM) results reveal that the surfaces roughness of the polymers can be controlled by selecting templates. Contact angle measurement shows that the water contact angles(WCA) rise with the increase of surface roughness, especially, the water contact angle on the PC surfaces prepared with specifications of 635mesh screen can reach to 152.3°, alias super hydrophobic surfaces.
Analysis of Thermal-Mechanical Coupling Strength and Fatigue Life of Piston of Low Speed Diesel Engine
Authors: Liu Zhong Ming , Li Cong , Hou Xiao Qin
Published: September 2012

In order to analyze the phenomenon of bolt preload when piston of low speed diesel engine is assembled and maximum explosion pressure and temperature during piston working impact on piston’s strength and fatigue life, Coupled analysis of mechanical stress and thermal stress on the piston of 5S60 low-speed diesel engine have been done, and the fatigue life of the piston on the alternating load condition was calculated. Firstly, the FEM-model which consists of 10-node tetrahedral meshes was built for the piston by using Hypermesh software with arranging different density of element quality which was guaranteed with the mesh parameters. Secondly, after setting the boundary conditions, the thermal stress, the mechanical stress and the coupling stress of the piston were calculated by using Abaqus software. Finally, the fatigue life of the piston on the alternating load condition was calculated by using nSoft software. The results indicate that the fatigue damage is easily occurred on the side of the surrounding area of the threaded holes, and that position should be made an especially consideration for design.
Inverse Design of a New Double-Link Luffing Mechanism of Lemniscate Floating Crane
Authors: Li Ke Qin , Jiang Cui Xiang
Published: September 2012

Lemniscate floating crane is a patent product. There are great differences in outward appearance, geometric shape, luffing performance between lemniscate floating crane and ordinary double-link type crane. Lemniscate floating crane has some advantages, i.e. lower centre of weight, practical and reasonable structure, strongly anti-wind and easy operation. Based on inverse design principle, kinematics analysis of luffing mechanism of lemniscate floating crane is solved. The equations of kinematics are obtained. Luffing character of lemniscate floating crane is more better than ordinary double-link type crane.
The Inverse Kinematics Analysis and Simulation of the Special Five Bar Cutting Mechanism for the Ellipse Section Shield
Authors: Wu Xiao Wei , Leng Chuan Guang
Published: September 2012

The hybrid driven special five bar mechanism is applied to cutting mechanism for the novel ellipse section shield machine. Based on the rod-group method, inverse kinematics of the special five-bar mechanism are analyzed and mathematics models of inverse kinematics are set up in order to obtain the equations and relations of position, velocity and acceleration between output motions and input motions. Some characteristic curves ofθP andθ4 are obtained through inverse kinematics analysis and the computer emulation, meanwhile the results of simulation proves the accuracy of the ideas in this paper. It lays an academic foundation for further research.
Application and Research on FEA while Promoting Vertical Milling Machine
Authors: Zhu Mei Hua , Wan Xiang Jun , Lu Jia Wei , Xie Hong , Xi Ying
Published: September 2012

This text makes static stress analysis on XH714 vertical milling machine by means of FEA and obtains diagrams of stress, strain, displacement and deformation of the whole machine as the result. Stiffness of the machine is solved according to the results and the first six natural frequencies and the modes of shape are gained during the research on the resonance area of the machine. Improvements on the structure of the machine based on the analysis are put forward which provides the theoretic basis for speeding up the spindle and increasing the length of the workbench.
Research on the Wear Characteristics and Wear Mechanisms of CrAlTiN Coated HSS Tools under Dry Cutting Conditions
Authors: Xiao Ji Ming , Bai Li Jing , Li Yan , Zheng Jian Ming , Yuan Qi Long
Published: September 2012

High-speed steel (HSS) turning tools was designed and sharpened according to the angles of the complex shape cutting tools. CrAlTiN coating was deposited using unbalance magnetron sputtering plating technique. By dry turning tests, the wear characteristics and wear mechanisms of the face were investigated. The results show that the face wear of the coated HSS tools is obviously different from that of the uncoated tools, the crater width is smaller, the boundary is jagged and the lowest position is away from the major cutting edge. Adhesive wear and local adhesive wear are the main wear mechanisms.
An Intelligent Tire Pressure Monitoring System Base on Wireless Radio Frequency Technique
Authors: Liu Guo Qiang
Published: September 2012

Many traffic accidents took place during the vehicle running, the main reason were some tire gas leakage, the lower tire-pressure, the higher temperature, and so on. So it was an important work to us to monitor the running state of tire. An intelligent Tire Pressure Monitoring System based on wireless radio frequency technique was designed. The Tire Pressure Monitoring System utilized a special sensor to test tire-pressure and temperature of interior tire, through a transmitting & receiver circuit to transmit and receive these signal, when the System got the working-state by processing these data and then warned us some danger exist in advance, which make us took some method to avoid these accident occurred. All these work will great decrease the traffic accidence.
Strength Analysis of Steering Knuckle Arm on Veyron Car
Authors: Wang Hong Wei , Yu Lin Lin
Published: September 2012

The steering knuckle arm is one of the important parts of Veyron automobile. In order to study its stress-strain distribution law under the forward and backward conditions, the geometric model was established under Pro/E, the pressure load which was applied on the inner curve surface was un-uniform in real condition, given triangle pressure loading, its strength under the two conditions was drawn with the finite element analysis, the maximum stress lied the joint part between inner curved surface and the threaded shaft, it was 199.984MPa. The results were in accord to the real conditions. The above research was useful for structural design and material handling.
Study on Process Planning of Auto Body Welding Line Based on Digital Factory
Authors: Zhang Sheng Fang , Gan Yong Quan , Zeng Kui , Ji Chang Jun
Published: September 2012

Auto body welding line process planning is one of the key sections which determines the production cycle of the whole automobile. Take the advanced digital factory software – Process Designer as developing platform, the production information management and the process planning of the auto body welding line are realized by creating manufacturing model and process model, and the auto body welding line process planning system is constructed, the realizing method and step of processing planning are described in detail. Furthermore, take one auto body floor welding line as an example, the 3D digital factory based on the process planning system is generated, and the planning results is verified. The result shows, applying the system in welding process planning, can shorten the time and increase the accuracy of process planning remarkably.
A Method for Solving Stiffness of Finite Length Self-Acting Gas-Lubricated Journal Bearing
Authors: Wang Jian Lu , Lu Yan Jun , Ma Hui , Zhang Yong Fang , Chen Yong Hui
Published: September 2012

Based on the differential transformation method, an efficient method is proposed to calculate stiffness of finite length self-acting gas-lubricated journal bearing. Time dependent Reynolds equation in gas lubrication of the self-acting journal bearing is solved, gas film pressure distribution and stiffness of the bearing are obtained. In comparison with the partial derivative method, the proposed method for solving stiffness of self-acting gas-lubricated journal bearing is verified. The proposed method can provide the theoretical reference to the dynamic design of self-acting gas-lubricated journal bearing-rotor system.
Analysis and Calculation of 3MW Wind-Turbine Main Shaft
Authors: Zhu Ren Sheng , Shen Jian , Liu Yong Mei , Zheng Zhen Zhen , Fang Zhen , Huang Qiang , Zhang Zu Liang
Published: September 2012

To find the changing regularity of stress and displacement, a 3MW wind-turbine main shaft was modeled and analyzed at startup time of operation. The results were verified by theoretical calculation. Parametric design of the shaft was used through orthogonal experiment method in which parameters were consisted of structural and load ones. The optimal regression equation, which indicated the relationship between the shaft stress or displacement and the parameters, was given by using polynomial regression with the test results.
Oxidation of U71Mn Steel under Pure Oxygen
Authors: Li Yong Zhi , Zhao Zeng Wu , Li Bao Wei , Wu Wen Fei , Li Shuo
Published: September 2012

Isothermal oxidations of U71Mn steels under pure oxygen, between 1027K and 1473K, are experimentally analyzed in this study. The results showed that Oxidation kinetics at different temperature from 1173K to 1473K are similar: mass increase per unit area as function of oxidation time follows parabolic role. Oxidation rate constants of the steel under pure oxygen, from 1173K to 1473K, keep exponential law as function of oxidation time.
Structure Design and Finite Element Analysis of a New Type Metallic-Disc Flexible Coupling for Diesel Generator Set
Authors: Min Xu Guang , Hu Guo Liang
Published: September 2012

Aiming at the shortcomings of fixed coupling and flexible coupling with rubber component used in the diesel generator set, a new type of metallic-disc flexible coupling for diesel generator set of 500kW power was designed. The working principle and theory analysis of the metallic-disc flexible coupling were expounded in detail. The simulation analysis was carried out to determine the optimal numbers and thickness of the metallic-disc using ANSYS software. The relevant results can provide some guidance for the improvement design of domestic diesel generator set.
Influence of the Chemical Elements of Welding Materials on Mechanical Properties
Authors: Tong Li Ge , Ding Hong Sheng , Wang Li , Bai Shi Wu , Sui Yong Li , Bai Lu
Published: September 2012

Based on artificial neural network (ANN), a mechanical properties prediction model for automatic welding is built. The input parameters of the model consist of the chemical elements and the diameter of the welding material and the outputs is the mechanical properties, i.e. yield strength, tensile strength and elongation. The ANNs model is established by Visual C++ based on improved back-propagation (BP) arithmetic with momentum coefficients, in which the sample data used are from automatic welding materials for X70 pipeline steel. The influence of chemical compositions, such as C, S, P, Si, Mn, Cu, Ti and Ni on the mechanical properties of welding materials are analyzed. The results show that the influence of metallic elements is significantly greater than the nonmetallic. For nonmetallic elements, not all the value of mechanical properties decreases with the increase of the content. The influence of C is critical, followed by P and S. For metallic elements, the influence of different elements on mechanical properties, such as the yield strength, the tensile strength, the elongation and the average Charpy impact toughness, is difference.