bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation of Iron-Oxide Coated Porous Ceramics Filter and Adsorption and Degradation on Methylene Blue
Authors: Li Fang Wen , Jia Hai Wu , Ma Song Jiang , Wu Mei Ling , Wu Xiang Jiang
Published: March 2010

The aim of the present work is to obtain iron-oxide coated porous ceramics filter (IOCPCF) via dip-coating and test its adsorption and degradation for methylene blue (MB). Porous ceramics filter (PCF) and ferric nitrate were used as substrate and modifier respectively. IOCPCF was characterized by spectrophotometer, X-ray diffraction, scanning electron microscopy, specific analyzer and Fourier transform infrared spectroscopy. The effect of its structure and performance on adsorption and degradation of MB aqueous solution was investigated. The results indicated that the average pore diameter, specific surface area and porosity of IOCPCF were 11.36 nm, 4.987 m2/g and 58.63% respectively. The major crystalline phase of iron coat was α-Fe2O3 which took on porous framework. Using the prepared material, the decoloration conversion for MB aqueous solution can reach 72.06% in 300min and be increased by 21.59% compared with original PCF.
The High Temperature Property of Ni/WC Infiltrated Composite Layer on Cast Iron Substrate
Authors: Yang Gui Rong , Song Wen Ming , Sun Xian Ming , Ma Ying , Lu Jin Jun , Hao Yuan , Li Yuan Dong , Wang Hai Tang
Published: March 2010

The surface composite layer Ni/WC on the cast iron substrate was fabricated through vacuum infiltration casting technique using Ni-based powder and WC particles with different content as raw materials. The micro-structure of infiltrated layer was compact for all infiltrated layer with different WC content, and WC particles distributed uniformly. The surface infiltrated layer was mainly composed of WC particle, intermetallic compound and solid solution. The thermal cycles were beyond 108 times when the infiltrated layer peeled off, which indicated that the specimen with infiltrated layer offered excellent thermal fatigue property. The oxidation rate of substrate was nearly three times as large as that of the infiltrated layer with 20% WC content. The oxidation resistance of the infiltrated layer improved obviously comparing with the substrate because the oxide layer for infiltrated layer was compact.
Research of Characteristics of Ni-W-P Nanocomposites Containing CeO2 and SiO2 Particles
Authors: Wang Jun Li , Xu Rui Dong , Zhang Yu Zhi
Published: March 2010

Ni-W-P-CeO2-SiO2 nanocomposites were pulse electrodeposited from the bath containing suspension of nano-sized CeO2 and SiO2 particles. The influence of heat treatment temperature on the structures and properties were studied. The phase structures, surface morphologies, microhardness and oxidation behavior were evaluated by XRD, SEM, microhardness and oxidation weight gain test. Additionally, the sequence of phase transformation of the nanocomposites was found to be as follows: amorphous phase→intermediate metastable→stable alloy phase. Nano-particles co-deposited into Ni-W-P alloy can inhabit the grains growth, increase microhadness and high temperature oxidation resistance during the course of heat treatment.
The Microstructure and Properties of Coating from Mo2FeB2 Cermet on Surface of H13 Steel by Reactive Flame Spraying
Authors: Zhou Xiao Ping , Hu Xin Bin , Xu Yi Sheng
Published: March 2010

The microstructure and properties of ternary boride ceramic coating prepared by reactive flame spraying on surface of H13 steel are studied as well as the microstructures, microhardness, wear resistance and thermal fatigue resistance of the coating. The results show that the Mo2FeB2 cermet coating by reactive flame spraying has good wear resistance and thermal fatigue resistance and its microhardness can even reach 1200 HV.
Novel Method for Improving Surface Performance of Rolling Bearing Raceway
Authors: Xia Xin Tao , Chen Jian Feng , Chen Long
Published: March 2010

The thin film can improve the surface performance of rolling bearings to reduce friction, vibration and noise and to increase the operating life of rolling bearings. This paper proposes a novel method for improving the surface performance of rolling bearings. This method is characterized by adding nanoparticles to the superfinishing liquid to form the nanofilm on the surface of the raceway by means of the special superfinishing technique. The experimental investigation proves that using this method, the fatigue life of the rolling bearing is obviously higher than that of the normal bearing. Surface topography photos of the Scanning Electron Microscope show that the thin film still exists after the fatigue test in 300 hours. Because of low cost, this method can be widely used in the production of rolling bearings.
Gradient Characteristic of Functionally Graded Cemented Carbide
Authors: Feng Ping , He Yue Hui , Sun Xiao Hua , Ni Guang Hong , Sun Yi Hua
Published: March 2010

The invention of functionally graded structure cemented carbide is a significant revolution. In this paper, graded structure cemented carbide with cubic carbide free layer (CCFL) was prepared. Using scanning electron microscope (SEM), metallographical microscope, electroprobe microanalyzer and microindentation, the gradient characteristics were investigated. The variation in elemental compositions from surface to inner is gradient, the concentrations of nitrogen and titanium are very low in surface layer, only element of tungsten, cobalt and carbon exist. A cobalt concentration peak occurs, which is higher than the average composition in bulk. Wherein binder phase piles up, its volume fraction is much higher than nominal value, resulting in a decrease in hardness and forming a tough layer.
Copper Multilayer Coating Prepared by Ultrasonic-Electrodeposition
Authors: Cui Rong Hong , Yu Zhi Ming , He Yu Ting , Shu Wen Jun
Published: March 2010

A kind of copper multilayer coating was prepared on stainless steel substrate using ultrasonic-electrodepositing method. The microstructure, hardness, wear resistance, adhesion and corrosion resistance of it were investigated respectively. The results show that the coating exhibits a multilayer structure and the thickness of each layer is about 0.3µm. The crystallite average diameter of it is obviously smaller than that of the ordinary electrodeposited copper coating. The diffraction peaks of Cu (200) and Cu (111) for it are obviously stronger, while Cu (220) for it is much weaker. Comparative investigations on the mechanical properties show that only the hardness of it is a little lower, whereas the wear resistance and the adhesion of it to the substrate are all evidently enhanced. The average start corrosion time of it in 20％ HNO3 solution is nearly three times delayed, and the corrosion rate is obviously decreased; anode polarization curves in 3.5% NaCl solution also show that the corrosion resistance of it is greatly improved.
Thermo-Mechanical Numerical Simulation on P91 Closed Upsetting Process
Authors: Liu Chang Yong , Zhang Ren Ji , Yan Yong Nian
Published: March 2010

Closed upsetting is the first step of steel pipe vertical extrusion technology. In this paper, the closed upsetting process was investigated by upper bound method, slip-line field and thermo-mechanical coupled FEM based on Deform 2D. The flow behavior, effective strain, temperature field and upsetting load were examined. The influence of billet temperature and die velocity on filling factor and upsetting load was discussed. The error percentage of upsetting load computed by upper bound method and FEM was less than ±1%. Simulation results showed that the closed upsetting process of P91 was more sensitive to temperature, while the impact of velocity was not as significant as temperature.
Synthesis and Characterization of Nickel-Iron-Silicon Nitride Nanocomposite
Authors: Marita Yusrini , Yaacob Iskandar Idris
Published: March 2010

Nickel-iron-silicon nitride nanocomposite thin films were prepared by electrodeposition technique. The deposition was performed at current density of 11.5 A dm-2. Nano-size silicon nitride was mixed in the electrolyte bath as dispersed phase. The effects of silicon nitride nanoparticulates in the nickel-iron nanocomposite thin films were investigated in relation to the amount of silicon nitride in the plating bath. X-ray diffraction (XRD) analysis showed that the deposited nickel iron film has face-centered cubic structure (FCC). However, a mixture of body-centered cubic (BCC) and face-centered cubic (FCC) phases were observed for nickel iron-silicon nitride nanocomposite films. The crystallite size of Ni-Fe nanocomposite coating decreased with increasing amount of silicon nitride in the film. From elemental mapping procedure, Si3N4 nanopaticles were uniformly distributed in the Ni-Fe film. The presence of silicon nitride increased the hardness of the film. The microhardness of the nickel-iron nanocomposite increased from 495 HV for nickel-iron film to 846 HV for nickel-iron nanocomposite film with 2 at. % Si. The coercivity of Ni-Fe nanaocomposite films increases with decreasing crystallite size.
Wear Behavior Of Chromizing-Titanizing Coating
Authors: Lou Bai Yang , Jin Ling Chuan
Published: March 2010

The wear behavior of chromizing-titanizing coating is examined in different media at room temperature and at elevated temperature, and compared with the wear behaviors of chromizing coating, titamizing coating and basis carbon steel. The structure of chromizing-titanizing coating is analyzed using electron probe, X-ray diffration and hardness. The results show that the chromizing-titanizing coating has better wear resistance than that of chromizing coating, titanizing coating and basis material. The wear resistance of chromizing-titanizing coating is mainly affected by the microstructure and composite of the coating which consists of complex compounds containing chromium carbides and TiC. The chromizing carbides exist mainly outside the coating and TiC exists mainly inside the coating. The complex compounds make the coating have both advantages of chromizing coating and titanizing coating, resulting in good wear resistance of chromizing-titanizing coating at room temperature and at elevated temperature.
Microstructure and Wear Resistance of TiC+Cr7C3 Reinforced Ceramal Composite Coating Produced by PTA Weld-Surfacing Process
Authors: Liu Jun Hai , Huang Ji Hua , Liu Jun Bo , Song Gui Xiang
Published: March 2010

A new type in situ reinforcing phase TiC+Cr7C3 ceramal composite coating was fabricated on substrate of Q235 steel by plasma transferred arc (PTA) weld-surfacing process using the mixture of ferrotitanium, ferrochromium, ferroboron and ferrosilicium powders. Microstructure and wear performance of the coating were investigated by means of X-ray diffraction (XRD), scanning electron micrograph (SEM), energy dispersive X-ray analysis (EDS), microhardness tester and wear tester. Results show that the composite coating consists of TiC, primary phase Cr7C3 , (Cr,Fe)7C3 and austenite. The composite coating is metallurgically bonded to the Q235 steel substrate. TiC particles present cubic and “dendrite flower-like” shape in the composite coating. The coating has high microhardness and excellent wear resistance under dry-sliding wear test conditions.
Effect of Diffusion Treatment on High-Temperature Oxidation Resistance of Multi-Arc Ion Plating Al Films on TiAl Alloy
Authors: Wu Xiang Qing , Xie Fa Qin , Hu Zong Chun , Shen Shi Da
Published: March 2010

In this paper, aluminum films were deposited on the TiAl alloy by multi-arc ion plating (MAIP) and subsequently diffusion-treated under 720°C for 4h. It is revealed by XRD and SEM/EDS that the film consisted of Al turn to an outer Al2O3 layer and inner TiAl3 layer after diffusion treatment. Cyclic oxidation tests show that the surface of the film formed a compact and continuous Al2O3 layer that prevents the TiAl substrate from oxidation, and the oxidation rate of the specimen with Al diffusion film is as low as 1.84 mg/cm2. The MAIP Al film after diffusion treatment is effective in improving the high-temperature oxidation resistance of TiAl alloys.
Control-Steps and Influence Factors of SiO2 Electrodeposition Process with Zn Coatings
Authors: Fan Yun Ying , Chen Dong Hua
Published: March 2010

In order to explore electrodeposition mechanism of composite plating, the effect of SiO2 particle concentration in the electrolyte on the component of Zn-SiO2 coatings was studied, and the control steps of composite electrodeposition were analysed. The results show that two-step adsorption of particles on the cathode proposed by Guglielmi also occurs during Zn-SiO2 composite electrodepositing process. When SiO2 particle concentration added in sulfate electrolyte is more than 10 g/L, the control-step of the electrodepositing process will turn from loose adsorption to strong adsorption, while the turning point of particle concentration in chloride plating system is 4 g/L. Through comparing and analysing the relationship between , and c, it is testified that Guglielmi model only can be effective when composite electrodepositing process is controlled by strong adsorption, while due to hydromechanical effect, it is not available when loose adsorption is dominant, and the critical concentration is not fixed in different plating system.
Structure and Oxidation Behavior of Gradient Zr/ZrN/Zr Diffusion Barrier on the Ni-Based Superalloy by Arc Ion Plating
Authors: Cai Yan , Tao Chun Hu , Lu Feng , Li Jian Ping
Published: March 2010

Gradient Zr/ZrN/Zr layer was deposited as a diffusion barrier between the NiCrAlYSi The overlay coating and Ni-base superalloy DZ125 by arc ion plating(AIP). The microstructure and high-temperature oxidation behavior of the diffusion barrier were studied. The results show that the gradient diffusion barrier is homogeneous and compact, and has strong bond strength with the substrate. The diffusion barrier is composed of three layers, among which the inner and outer layers are rich in Zr, and the middle layer is rich in ZrN. The main phase structure of the diffusion barrier is ZrN(200). During high temperature oxidation at 1100°C, the Zr/ZrN/Zr/HY3 compound coating system presents excellent oxidation resistance.
Oxidation Study of APS Thermal Barrier Coatings in Elevated Temperatures
Authors: Li Zhi Yong , Bao Rui , Zhang Jian Yu , Fei Bin Jun
Published: March 2010

TBCs is a type of multilayer systems, mainly used in the thermal parts of aero engine, acting as the part of heat insulation. The using temperature of parts can be improved because of the being of TBCs. TBCs is one of the most advanced high temperature coatings, and it has many perfectly properties, including the chemical property at high temperature, anti-erode and thermal insulation [1,2]. If TBCs spall from the base, the base will expose in the high temperature, then, rapidly destroy. TBCs generally include three layers, superalloy, bonding layer, insulation layer, and the thermally grown oxide (TGO) between the bonding layer and insulation layer. Justly because of the being of TGO, the TBCs easily failed [3,4]. Although many researchers studied the oxidation of TBCs, the investigation of the relations between oxidation and oxide temperature has not been done by far. So, the work put the emphases on the discussion of APS TBCs’ oxidation property in different temperatures by experiment.
Research on In-Flight Property of Particles in Plasma Spray Forming
Authors: Li H.Y. , Shi Yu Ying , Zeng Hao Ping , Xu Wen Ji
Published: March 2010

Plasma spraying has been carried out under different spraying parameters, the particle in-flight behaviors have been measured to analyze the influence of argon flow rate, hydrogen flow rate and electrical current on the particle temperature and velocity. The particle velocity increased remarkably with the increase of the argon flow rate. The particle temperature was mainly influenced by the hydrogen flow rate, and increasing electrical current resulted in the increase of the particle temperature and velocity to some extent.
Study on Activated Carbon /Polyaniline Electrode Materials for Supercapacitorsts
Authors: Tian Yan Hong , Wu Bo Rong , Mao Ding Wen
Published: March 2010

Activated carbon (AC)/polyaniline (PANI) composite electrode materials were synthesized in this article. The effect of preparation such as BET surface area and porous size of AC on the electrochemical performances of AC/PANI composite material was investigated. The electrochemical performances of the composite were tested with cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectrometry in 6mol/L KOH solution using Hg/HgO as reference electrode. Composite surface morphology was examined by scanning electron microscope (SEM). The result shows that when the ratio of AC to aniline increases, the conversion of aniline and the capacitance value of composite also increase in keeping the ratio of AC to aniline constant. When AC: aniline : (NH4)2S2O8 =7:1:1, the conversion of aniline up to more than 95% and the capacitance value of electrode materials increased from 239F/g(pure AC) to 409F/g, which is 71.1% higher than pure AC. Pore structure of AC also has great effect on electrochemical performances of electrode material. With the increase of proportion of mesoporous, the electrochemical properties of composite are greatly increased.
Tensile and Bending Strengths of TR-30s Carbon Fiber Three Dimensional Braided Composites at Different Temperature
Authors: Guo Yun Fei , Yang Jian , He Ye Hong , Li Jia Lu
Published: March 2010

With the development of technology, composites are used more broadly, especially at different temperature. So it is very important to research the mechanical properties of composites at different temperature. Three dimensional braided composites are new composites with high performances, in which fiber-tows are interlacing in space with multi-direction and pass through the thickness to form a no-laminated and integrated structure. However researches on the mechanical properties of three dimensional braided composites are almost at room temperature. In this paper, the tensile and bending strengths of three dimensional braided composites (TR-30s carbon fiber/epoxy) at 23 oC and 150 oC are researched respectively. The results indicate that the effect of temperature on the tensile strength and bending strength of 3D braided composites is obviously different. The average tensile strength of 3D braided composites at 150 oC is almost the same as that at 23 oC. However the average bending strength of 3D braided composites at 150 oC is mush lower than that at 23 oC. This means that the effect of temperature on different mechanical properties is different and application temperature should be taken care of when 3D braided composites bear different kind of loads.
Effects of Al Content on Phase Composition of Zr-Al-O-N Composites
Authors: Wang Rong Lin , Bu Jing Long , Wang Zhi Fa , Sun Jia Lin
Published: March 2010

Zr-Al-O-N composites were prepared in N2 atmosphere at 1600oC with Ca-PSZ and Al powders as raw materials. Phase composition of the composites and formation reaction mechanism were investigated by XRD and SEM analyses. With Al content increaseing from 1% to 50%, phase composition of the composites were changed step by step. The results showed that phase compositions of the composites are related to Al content.
Effects of Nano-Al2O3 Additions on Microstructures and Properties of WC-8Co Hard Metals
Authors: Sun Lan , Xiong Ji , Guo Zhi Xing
Published: March 2010

To investigate the role of nano-Al2O3, WC–Al2O3–8wt%Co hard metals was mixed with 0-1.2 wt% nano-Al2O3 and prepared by conventional sintering (CS) for 2 h at 1440°C to see whether the addition of Al2O3 could improve densification behaviour, the microstructure and mechanical properties of the samples. The results showed that the use of Al2O3 nanoparticles as dispersions could reduce the porosity of WC-Co alloy and decrease the relative density; it could also inhibit the growth of the grains of WC-Co hardmetal to enhance the hardness and transverse rupture strength of the alloy in a proper range. The influence of Al2O3 content on the magnetic properties including coercive force and saturated magnetic intensity of the WC–Al2O3–8wt%Co hardmetals manifested the additive of nano-Al2O3 have effect on the WC grain growth inhibition and the formation of decarbonization phase in the alloy.
Tic Particle Reinforced Iron Based Composite Coating by Submerged-Arc Welding Added Alloy Powder
Authors: Liu Jun Bo , Wang Li Mei , Liu Jun Hai
Published: March 2010

TiC particle reinforced iron based composite coating were in situ synthesized on surface of Q235 steel by Submerged-arc Welding (SAW) using the mixture consisted of ferrotitanium, ferrochromium, iron and carbon powders. Microstructure of the coating was observed by scanning electron microscope（SEM）and X-ray diffraction(XRD). Microhardness was measured by microhardness tester. Results indicated that the fine TiC particles were formed by using SAW process and dispersed in the matrix. And the particles sizes were less than 2μm. Microstructure of coating consists of TiC particles, martensite and austenite. The microhardness of coating is HV575~HV617, which is about 3 times of that of the based metal.
Manufacture and Tribological Properties of C/C-SiC Brake Composites Fabricated by Warm Compacted In Situ Reaction
Authors: Peng Xiao , Zhuan Li , Xiang Xiong
Published: March 2010

Carbon fibre reinforced carbon and silicon carbide dual matrix composites (C/C-SiC) were fabricated by warm compacted in-situ reaction. The C/C-SiC composites microstructure and tribological properties at different brake speeds were investigated. The results indicated that the composites were composed of 58 wt% C, 37 wt% SiC and 5 wt% Si. The density and open porosity were 2.0 g•cm-3 and 10%, respectively. The C/C-SiC brake composites show excellent tribological performance, including a good stability of brake, the coefficient of friction between 0.57 and 0.67, and the wear rate less than 2.02 cm3•MJ-1. These results show that the C/C-SiC brake composites are the promising candidates for advanced brake and clutch systems.
Influence of Nanosilica/Polyurethane Composite Coating on IR Effectiveness and Visible Light Transmission Properties of Polyethylene
Authors: Chee Ching Yern , Yaacob Iskandar Idris
Published: March 2010

Polyethylene (PE) film was coated with nanosilica-polyurethane layer using rod Mayer process. The nanosilica-polyurethane system was prepared by dispersing nanosilica (SiO2) powder into solvent borne polyurethane (PU) binder under vigorous stirring. Various compositions of nanosilica-polyurethane slurry were prepared. A battery of characterization procedures were used to study the properties of the nanocomposite coating. ATR FTIR confirmed the presence of functional groups of silica and polyurethane. The uniformity of silica dispersion was probed using scanning electron microscopy (SEM). With the introduction of nanosilica to polyurethane binder, the visible light transmittance and ultra-violet (UV) radiation of nanosilica-polyurethane system reduced with increasing nanosilica content and coating layer thickness. The PE coated with nanocomposite containing 14wt% nanosilica and with 8 µm coating thickness showed >88% transmittance in the visible light region. Infrared (IR) effectiveness (between 7 μm to 13 μm wavelengths) measurements by FTIR also showed that nanosilica/polyurethane system coating on PE film surface greatly improved the infrared opacity properties of PE film.
Friction and Wear Behaviors of Si3N4 Sliding against M50 Bearing Steel in Vacuum
Authors: Tong Yong Xing , Wang Li Qin , Gu Le
Published: March 2010

The friction and wear performances of Si3N4 ceramics sliding against bearing steel and to find optimal operating condition against M50 bearing steel couples under high vacuum surroundings were investigated. The tests were studied on the ball-disk machine under different loads and steady sliding velocity. The worn surfaces of tested samples were examined using optical microscope，SEM and XPS. The results showed that the friction coefficient of Si3N4 was decided by the applied load, the critical load of Si3N4’ friction coefficient was 10N applied load; The critical load of Si3N4’ specific wear rate was 5N applied load, the specific wear rate of Si3N4 drop rapidly as the applied load exceeded the critical load; The dominant wear mechanisms of Si3N4 ceramics were adhesion wear, brittle facture and furrow wear in vacuum.
Synthesis and Mechanical Property Evaluation of Ti-TiAl Metal-Intermetallic Microlaminate Composite
Authors: Ma Li , Wang Hai Bo , Hu Zhao Hui
Published: March 2010

A microlaminate consisting of Ti and α2-Ti3Al+γ-TiAl has been synthesized using electron beam physical vapor deposition technique. The microstructure and various properties have been explored. It is demonstrated that the nano-hardness and elastic modulus of Ti layer and Ti-Al layer are of gradient distribution according to the distance to the interface layer which may be results from the pile-up effect and the stress concentration at interface. The presence of Ti layers will lead to the cracks stagger along the inter-laminar interface or the layer due to which micro laminate expresses a good characteristic of delayed fracture. The toughening mechanisms are that the crack deflection and micro-bridge connection caused by the toughening layers increases crack propagation resistance.
Experimental Research on Low-Velocity Impact Properties of 3D Braided Composites
Authors: Jia Qi , Jiao Ya Nan
Published: March 2010

This research dealt with the impact properties of glass fiber reinforced composites manufactured from different structures of three-dimensional braided preforms. Three different architectures of the braid structures, 4-Direction, 5-Direction and 6-Direction, were investigated together with three further various braiding angles of each architecture. The effect of architecture and braiding angle parameters upon the impact was examined. Damage morphology of the impacted materials was characterized. It has been found that the parameters affected the damage resistance and tolerance of composites evidently. 6-Directional composites showed higher impact toughness than the others with same braiding angle. Failure of the specimens with small damage area revealed the brittle characteristic of 3D braided composite.
Manufacturing Technique and Physical Property of Metal Wires/ PP Nonwoven Selvedges Complex Ply Yarns and Knitted Fabrics
Authors: Lou Ching Wen , Lin Chin Mei , Chen An Pang , Yang Yi Chang , Chen Chueh Pin , Lin Jia Horng
Published: March 2010

In this study, nonwoven selvedges served as core yarn which was wrapped with stainless steel wires. Core yarn was added with functional materials such as stainless steel wires or copper wires or both. Functional polypropylene nonwoven selvedges (PNS) complex ply yarns were made using a rotor twister machine. The wrapped density of stainless steel wires was changed as 0.5, 1.5, 2.5, 3.5 and 4.5 turns/cm and the speed of rotor twister was set at 8000 rpm. Shown in the mechanical property test of complex ply yarn, when speed of rotor twister was at 8000 rpm; wrapped density was 2.5 turns/ cm; and functional materials were copper wires and stainless steel wires, complex ply yarns made of polypropylene nonwoven selvedges (PNS) had the maximum breaking force as 47.76N and maximum breaking elongation as 47.93%.
Theoretical Analysis and Experimental Investigation into Hydrodynamic Pressure and Coolant Lift Force in Flood Delivery Grinding
Authors: Hou Ya Li , Yao Fu Xin , Li Chang He , Ding Yu Cheng
Published: March 2010

In the grinding process, conventional method of flood delivering coolant fluid by a nozzle in order to achieve high performance finishing. However, hydrodynamic fluid pressure can be generated ahead of the contact zone due to the wedge effect between wheel peripheral surface and work surface. In the paper, a theoretical hydrodynamic pressure modeling is presented for flow of coolant fluid through the grinding zone in flood delivery grinding. Moreover, coolant induced force can be calculated by integrate the hydrodynamic pressure distribution over the whole contact length. The theoretical results show that the hydrodynamic pressure was proportion to grinding wheel velocity, and inverse proportion to the minimum gap between wheel and work surface and the maximum pressure value was generated just in the minimum gap region in which higher fluid pressure gradient occuring. It can also be concluded the pressure distribution was uniform in the direction of width of wheel except at the edge of wheel because of the side-leakage. Furthermore, the hydrodynamic pressure and coolant induced force at wedge-like zone were also investigated experimentally. The experimental results show the theoretical model is agreement with experimental results and the model can well forecast hydrodynamic pressure distribution at contact zone between grinding wheel and workpiece.
Study on the Stability of High-Speed Milling of Thin-Walled Workpiece
Authors: Wang Tong Yue , He Ning , Li Liang
Published: March 2010

Thin-walled structure is easy to vibrate in machining. The dynamic milling model of thin-walled workpiece is analyzed based on the analysis of degrees in two perpendicular directions of machine tool-workpiece system. In high speed milling of 2A12 aluminum alloy, the compensation method based on the modification of inertia effect is proposed and accurate cutting force coefficients are obtained. The machining system is divided into “spindle-cutter” and “workpiece-fixture” two sub-systems and the modal parameters of two sub-systems are acquired via modal analysis experiments. Finally, the stability lobes for high speed milling of 2A12 thin-walled workpiece are obtained by the use of these parameters. The results are verified against cutting tests.
The Friction Coefficient and Self-Organization Feature on Rake Face when Turning Hardened Steel with Coating Tools
Authors: Hou Zhi Gang , Zhao Jun , Xu Li Qiang , Guo Zhong
Published: March 2010

The friction coefficient on rake face was calculated through the cutting forces tested in a series of cutting experiments. These experiments were performed for turning two kinds of hardened steel with four types of coating tool by orthogonal experimental method. The curves of the friction coefficient changing with the cutting process and its dependence on the cutting parameters were analyzed in detail. The results show that the friction coefficient on rake face decreases rapidly during the cutting progress and comes to a steady value, which could be an indication of the self-organization when turning hardened steel with coating tool.
Finite Element Simulation of Ultrasonic Vibration Orthogonal Cutting of Ti6Al4V
Authors: Tang Zhi An , Liu Chang Yi , Yi Jun Jie
Published: March 2010

In this paper Finite Element Methods (FEM) were used to simulate the ultrasonic vibration Orthogonal cutting of titanium alloy Ti6Al4V. Machining conditions were similar to those used for manufacture. Material constitutive applied Johnson-Cook model combining elastic and plastic deformation, the material hardening for extreme shear strain and strain rate, material softening for adiabatic shear of chip flow-zone. Chip separated criteria adopted arbitrary Lagrangian Euler algorithm (ALE). Heat sources included the rake face chip flow under conditions of seizure and chip/tool friction, clearance face tool/workpiece friction. Thus, the orthogonal ultrasonic vibration machining of Ti6Al4V FEM models were established. The simulation results included the chip formation, the cutting force/stress and temperature distributions through the primary shear zone and the chip/tool contact region. The cutting force, cutting temperature of the ultrasonically and conventionally machining were compared. The reasons of the decrease of chip deformation coefficients, cutting force and temperature and the increase of shear angle in ultrasonic machining were discussed.
Study on Metals Behavior Subjected to Cyclic Loading Based on Bauschinger Effect of Reversible Fine Machining Sequence
Authors: Wu Wen Ge , Huang M.X. , Mei W.T.
Published: March 2010

Reversible cutting method is a new research thesis proposed to shorten processing route, decrease tool number and handling time, increase machining efficiency. Based on nonlinear hardening during reverse loading and the change of the Bauschinger effect factor with plastic strain, reverse loading released strain energy of elastic responses of machined underlayer. The chip formation model of reversible finish cutting was established. The difference between the advance and return stroke was analyzed in crystal slipping and elongating, residual stress, micro-hardness of machined surface. Experimental research indicted that the results of micro-hardness of reversible fine machining technique are smaller than that of general fine machining, the circumferential residual stress at the finished surface is compressive, the surface roughness of machined surface are smaller than that of general fine machining. The kinematic hardening models of the advance and return stroke finishing cutting based on Bauschinger effect is presented.
Four-High Mill with Statically Determinate Characteristics of Micro Displacement of the Components
Authors: Li Ming , Zheng Yong Jiang , Shen Guang Xian , Ma Jing Liang
Published: March 2010

The theory of micro dimensional behavior on rolling mill is used for a typical 450 mm hot plate four-high mill. A statically determinate device is adopted on the back-up roll system to adapt to the micro-dimensional deflection. We replace the traditional single base with the force divided base for the rolling load. To make the rolls parallel, a worm-screw device is set in the chock, with a clearance between the chock and the stand window to allow convenient roll replacement and retain a thermal expansion space. In the new mill, the center line of the roll body is constant when the rolling is stopped or running. It can be predicted that the mill will be strengthened two times and the roller bearing life will be prolonged ten times.
Influence of Radial Depth of Grinding and Finishing Process on Surface Residual Stresses in Grinding AF1410 Ultrahigh Strength Steel
Authors: Song Ge , Li Jian Feng , Sun Jie , Zhang Wen Guang
Published: March 2010

AF1410 steel is a kind of high alloy secondary hardening ultrahigh strength steel, which is developed for structural applications where the combination of high strength and high fracture toughness is required. The distribution of residual stresses affects the fatigue life and stress corrosion resistance of the components in service. The distribution of surface residual stresses on the components should be controlled by the machining process. Little investigation about the residual stresses on AF1410 steel had been studied previously. In this study, two AF1410 cylindrical workpieces were machined by cylindrical grinding with a white alumina (WA) grinding wheel and under water base cooling fluid. Two groups of experiments were set to investigate the influences of different radial depths of grinding and the finishing process on the residual stresses. The residual stresses along grinding and feed directions were measured respectively using X-ray method. The rule of the residual stresses variety with the radial depth of grinding (ap) was studied. The reasons causing the distinctions of the residual stresses between two groups of experiments were analyzed and the optimized grinding parameters were obtained.
Effect of Tool Inclination Angle on Surface Quality in 5-Axis Ball-End Milling
Authors: Han Shi Guo , Zhao Jun
Published: March 2010

Because of the complexity of five-axis ball-end milling process, it is difficult to control the quality of the finished parts. It is well known that one of the most important differences between 5-axis and 3-axis CNC machining is whether tool-axis vector is variable in milling process. In this paper, the tool orientation is researched in order to obtain desired surface quality and improve production efficiency. And the influence of tool inclination angle on surface integrity, especially surface topography/roughness and residual stress in high-speed milling of P20 die steel is studied by means of milling experiments including 8 cases of ball-end milling of freeform surface. Finally, the optimal tool inclination angles including lead angle and tilt angle and milling method were obtained for 5-axis ball-end milling. And in the meanwhile, cutting condition can be improved and better surface quality can be obtained by selecting reasonable tool inclination angles and up/down milling method.
Low Temperature Synthesis of TiO2 Nanorods with Tunable Aspect Ratios from Ti and NH4Cl Powders
Authors: Liu Yan , Zhang Yong Cai , Zhang Ming
Published: March 2010

TiO2 nanorods with tunable aspect ratios were synthesized directly via heating different molar ratios of Ti and NH4Cl powders in air at 400 °C for 3 h. The resultant products have been characterized by means of X-ray diffraction (XRD), Raman spectra, and field emission scanning electronic microscope (FESEM). The proposed method is of simpleness, low temperature and low cost, which may be suitable for large scale production of multifunctional TiO2 nanomaterials
Preparation of Manganese Zinc Ferrite Nanoparticles by Polymer Matrix Templated Synthesis
Authors: Noor Siti Hajar Mohd , Yaacob Iskandar Idris
Published: March 2010

MnxZn1-xFe2O4 nanoparticles with x = 0, 0.2, 0.4, 0.5, 0.6 and 1.0 were synthesized by polymer matrix templated synthesis. Ion exchange resins in a form of spherical beads that contained nanopores were used to precipitate the nanoparticles. The synthesized nanoparticles were characterized using several characterization techniques including X-ray diffractometry, transmission electron microscopy and alternating gradient magnetometry. XRD patterns showed that only manganese zinc ferrite nanoparticles were formed. Calculation of crystallite size from x-ray peak broadening showed that the crystallite sizes were within the range 5-11 nm. The crystallite size increased with increasing Mn concentration. TEM images showed that the particles were almost spherical with diameters ranging from 8-19 nm. Magnetization curves passed through the origin and showed no hysteresis indicated that the particles are superparamagnetic. The magnetization value at 10kOe applied magnetic field increased with increasing particle size which was mainly due to the effect of manganese content of the nanoparticles.
Solution of Singularity Points in Strip Rolling by Rigid Plasticity Finite Element Method
Authors: Li Chang Sheng , Mei Rui Bin , Liu Xiang Hua
Published: March 2010

The concept of the first and the second singularity point was introduced in the paper. The singularity points would lead to the iteration divergence in the solution of rolling by rigid plasticity finite element method. Double velocity model and parabolic model of relative slip velocity were proposed for solution of the first and the second singularity point respectively. The influence of the models to improve the effects of singularity point on calculating time and iteration step was discussed according to the practical strip rolling condition. The results showed that for the element numbers from 200 to 2000, the iteration step and total calculating time was reduced about 8~67% by the double velocity model in the same condition compared to normal model for the solution of first singularity point. The iteration step and calculating time was reduced about 15~61% with the parabolic model of relative slip velocity. The double velocity model and parabolic model of relative slip velocity could be used to improve the convergence and increase efficiency of the solution in strip rolling by rigid plasticity finite element method.
Effect of ZnO Nanoparticles on the UV Light Fastness and Climate Resistance of PVC Film
Authors: Li Xi Hong , Chen Wei , Xing Ya Ge , Yung Juan , Zhang Pei Pei
Published: March 2010

In this work, effect of ZnO Nanoparticles on the UV light fastness and climate resistance of PVC film was investigated. The results showed that after 4 h irradiation and 4 times in the cycle system, tensile strength and elongation at break of the ZnO-coated films decreased, but still larger than that of the blank PVC-based films. The analysis of the results revealed that the ultraviolet light fastness and climate resistance of the ZnO-coated PVC film was improved, which may be attributed to the ZnO nanoparticles coated on the surface.
The Effect of Precipitates on the Bio-Corrosion Property of As-Cast Mg-Zn-Y Alloys
Authors: He Wei Wei , Yang Ke
Published: March 2010

Microstructure and bio-corrosion properties of as-cast Mg-Zn-Mn-Y alloys are investigated in detail to reveal the effect of the precipitate on the biocorrosion properties for biomedical application by scanning electronic microscopy electrochemical measurement and immersion tests. Alloy I is composed of primary Mg, Mg7Zn3 and I-phase, while there is only one secondary phase (W-phase) in alloy II. Alloy with W-phase exhibits a higher corrosion resistance and a lower corrosion current density. W-phase acts as a cathode and Mg matrix as an anode at the interface between W-phase and Mg matrix, while I-phase acts as an anode and Mg matrix as a cathode. The standard electrode potentials of secondsry phases are in the following order: W-phase>Mg>I-phase.
Residual Stresses in Fabrication of Core-Veneered Ceramic Prostheses
Authors: Zhang Zhong Pu , Zhou Shi Wei , Li Qing , Li Wei , Swain Michael V.
Published: March 2010

Fabrication of multilayered ceramics signifies an important topic in many advanced applications aerospace and prosthetic dentistry. This paper presents a numerical approach to characterising the transient thermal responses and corresponding thermal residual stresses that are developed in the bi-layered dental ceramic crowns model under a controlled cooling rate from a temperature around its glass transition temperature (typically 550°C) to room temperature (25°C). Finite element method (FEM) is adopted to model the residual stresses in normal or rapid cooling fabrication process. The demonstrative examples take into account the effect of thickness in core veneered all-ceramic restorative prosthesis (specific porcelain bonded to an alumina or zirconia core layer), cooling rates and mismatches in temperature-dependent material properties such as thermal expansion coefficients, specific heat and Young’s modulus. The model of transient ceramic fabrication processing showed significant potential to development of optimal prosthetic devices.
Effect of LPG Injection Methods on Engine Performance
Authors: Li Xi Qin , Yang Li Kang , Pang Mao , Liang Xia Juan
Published: March 2010

Three methods of injecting liquefied petroleum gas (LPG) were tested on an LPG engine. The injection methods were gaseous phase LPG injection at intake port, liquid phase LPG injection at intake port, and liquid phase LPG in-cylinder direct injection. The experimental results showed that the maximum torque developed with liquid phase LPG-engine direct injection, was 13.8 percent higher than gaseous phase LPG injection at the intake port. It was found that liquid phase LPG direct injection was an effective way to overcome power deterioration of an LPG-engine as compared to a gaseous phase LPG injection supply method.
Waste Beverage Containers Automatic Green Recycling Technique Based on the Optical Image Inspection
Authors: Ji Rui Hai , Du Hai Qing , Liu Xin
Published: March 2010

Aiming at the problem of effectively recycling waste beverage containers, an automatic green recycling technique based on the optical image inspection is proposed. The basic principle and realization steps of the automatic green recycling technique are expounded. By using the optical image inspection technique and object contour recognition technique, the waste beverage containers are classified from different manufactures. The problem of waste beverage containers automatic recycling is solved, the cost of retailers is reduced and the waste beverage containers are recycled effectively. This automatic green recycling technique is significant for the recycling economy and sustainable development.
Vibration Characteristics of Ni Thin Film Diaphragm by Acoustic Wave
Authors: Cho Gue Serb , Lee Won Sik , Ko Se Hyun , Son Seong Ho , Lee Chang Woo , Kim Jun Ki
Published: March 2010

Vibration characteristics of 5μm- thick Ni film were investigated with applying acoustic wave to the Ni diaphragm of 2mm x 2mm unit size. In the modal analysis, the first resonance mode of the diaphragm showed an out-of-plane piston-like movement and the first natural frequency was 1,643 Hz, whereas in this experiment, the first natural frequency appears at about 1,300 Hz under sound pressure of 0.2 Pa. The amplitudes of diaphragm increase with increase of sound pressure level in the applied frequency range from 300 Hz to 1,000 Hz, indicating that area of diaphragm influences directly the amplitude.
Study on Tool Wear of Cutting Ti-6Al-4V with Water Steam as Coolant and Lubricant in Green Machining
Authors: Zhang Yue , Han Rong Di , Sun Tai Li , Li Qi Dong , Zhang Xi Chuan
Published: March 2010

To achieve green machining of titanium alloy Ti-6Al-4V with water steam cooling and lubricating, a 600-800w minitype generator is developed. Compared to dry and water-based emulsion, the using of water steam improves Ti-6Al-4V machinability and prolongs the tool life about 1 time and 0.5 times. And if the same tool life was selected, it would be easy to obtain that as water steam applied the cutting speed can increase about 15% and 10%. As a result, the productivity can be increased. The excellent cooling and lubricating action of water steam could be summarized that water molecule has a small diameter and high speed, can be easily and rapidly to penetrate the capillaries and proceed adsorption in the cutting zone. The results indicate that the using of water steam has the potential to attain the green machining of titanium alloy Ti-6Al-4V.
Extrusion Modeling of Solid Plug Flow of Co-Rotating Twin Screw Pulping Extruder
Authors: Shen Xiao Yang , Wang Ping , Liu Shao Gang
Published: March 2010

In order to calculate important design parameters, screw axial force and power consumption of twin screw pulping extruder (TSPE), considering actions of the solid material plug in reverse thread of the TSPE and according to static balance principle, an extrusion model including plug flowing and shearing in reverse thread is proposed in the paper. Based on the model, screw axial force, screw torque, power consumption and flow rate can be derived. When changing thread lead numbers or slot width on the flight of the reverse thread, theoretical calculating results and testing results are better consistent.
Similarity-Based Integrated Scheduling of Machining Processes in the NC Resource Grid
Authors: Luo Ya Bo , Tang Ming Chun
Published: March 2010

Grouping the similar processes is a good approach to improve the manufacturing efficiency, however, which is facing with two difficulties of the group automation and the constraints coupling. Regarding the numerical control (NC) machines and tasks as a grid system, this paper proposes a similarity-based tactic to solve the above difficulties. First, the methodology for analyzing the similarity among NC tasks is proposed to implement group automation taking the similarity principle as theory foundation. Second, based on the results drawn from the first step, the complex constraints including similarity constraints, delivery date constraints, and serial constraints are coupled to develop an integrated scheduling model. Finally, the integrated model is solved and the optimum solution is gotten using a specialized ants algorithm.