bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and Characterization of CuO-Doped ZnO
Authors: Li Yan , Zou Yun Ling , Li Jian Gang
Published: November 2010

ZnO is an important functional semiconductor in application of photoelectric devices. ZnO nano-tubes and the CuO-doped ZnO have been successfully fabricated via hydrothermal method and a solution routine. The samples were characterized by X-ray diffraction, scanning electron microscopy, Fourier transformation infrared spectroscopy and room temperature photoluminescence measurement. The results show that the lattice space (d-value) of the CuO-doped ZnO increases while introducing CuO into its structure. Due to the interaction between Cu2+ and the surface atoms of ZnO, a photoluminescence confinement were observed in the CuO-doped ZnO compared with that of nano ZnO.
Test on the Mortar Mix Ratio with Aeolian Sand of Mu Us Desert
Authors: Li Xi An , Zheng Hui Fang , Li Xiao Xiang , Ye Wan Jun
Published: November 2010

In this paper, series of mortar tests with Aeolian sand as its fine aggregate were launched. Result shows that the admixture flyash can effectively improve the liquidity and water capacity, hence to improve the workability of the mortar. As the mortar age increases, with the surface activity of flyash gradually brought into full play, the long-term mortar strength can be ensured. The compound additive with polycarboxylic as the water reducing agent, neopelex as the gas-forming agent and the sodium silicate, reduced the required water by about 15% without changing the consistency of the mortar mixture. United Expansive Agent (UEA) was used to reduce the shrinkage rate of the mortar mixture. The Cost Performance Indicator (CPI) was introduced to evaluate the cost performance of the mix mortar, suggesting that the CPI of the mix mortar is 1.38 times of that of the mortar with river sand. Test results of various index value shows that the mortar mix ratio obtained in this paper can meet the need of plastering and masonry engineering.
Prepared of Flower-Like CuO via CTAB-Assisted Hydrothermal Method
Authors: Zou Yun Ling , Li Yan , Zhang Nan , Li Jian Gang
Published: November 2010

Flower-like CuO nanostructures have been prepared via cetyltrimethylammonium bromide (CTAB)-assisted hydrothermal method. Here, CuCl2•2H2O was used as copper raw material, and sodium hydroxide was used as precipitate. The resulting CuO powders were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). X-ray diffraction (XRD) pattern exhibited the nanocrystalline nature with monoclinic structure for the as-synthesized nanostructures. FESEM images indicated that the flower-like CuO nanostructures are composed of many interconnected nanosheets in size of several micrometers in length and width and 60-80 nm in thickness. The possible formation mechanism of flower-like CuO nanostructures was discussed.
Effects of Salt Corrosion and Freeze-Thaw Cycle on Rubberized Cement-Soil
Authors: Wang Feng Chi , Li Peng Fei , Ye Xiao Peng
Published: November 2010

In order to improve salt corrosion and frost resistance of cement-soil, the waste tire rubber powder was mixed into cement-soil to form rubberized cement-soil. In the salt corrosion and freeze - thaw cycle (SCFT) conditions, compressive strength of rubberized cement-soil increases first and then decreases with rubber content increasing. The more numbers of SCFT cycles, the more strength slip increases. But in high concentration conditions, the strength of rubberized cement-soil with 5%-10% rubber content reduces. With the solution concentration or SCFT cycles number increasing, peak stress of rubberized cement-soil and common cement-soil gradually reduces, but strength slip of rubberized cement-soil is lower than of cement-soil. Studies indicate that the performance of rubberized cement-soil surpasses common cement-soil decided by the relationship between rubberized cement-soil skeleton elastic behavior and coupling expansive force.
VOCs Decomposition Using Multiple Catalysis in Non-Thermal Plasma Processing
Authors: Zhu Tao , Wan Yan Dong , Zhang Chun Hui , Sun Ming Han , He Xu Wen , Xu Dong Yao , Shu Xin Qian
Published: November 2010

A series of experiments were performed for toluene removal from a gaseous influent at normal temperature and atmospheric pressure by adsorption & non-thermal plasma strength & nano-catalysis technology. Non-thermal plasma was generated by dielectric barrier discharge. Sorbent & nano-catalyst were called combined catalyst which included MnO2/γ-Al2O3 and nano-Ba0.8Sr0.2Zr0.1Ti0.9O3 catalyst. MnO2/γ-Al2O3 has an advantage for ozone removal, while nano-Ba0.8Sr0.2Zr0.1Ti0.9O3 is a kind of good material for improving energy utilize rate. The results showed the synergistic technology resulted in greater enhancement of toluene removal efficiency and energy efficiency and a better inhibition for O3 formation in the gas exhaust. Based on data analysis of FT-IR, the experiment discussed decomposition mechanism and reaction process of toluene. The results showed that synergic effect could control byproducts effectively.
Development and Characteristic of Bacterial Cellulose for Antimicrobial Wound Dressing
Authors: Zhang Hai Yue , Yan Xiao Juan , Jiang Yan , Cong Juan
Published: November 2010

Bacterial cellulose (BC) material was obtained through fermentation by Acetobacter xylinumis with superior functional properties. BC is an interesting material for using as a wound dressing since it provides moist environment to a wound and results in a better wound healing. With the aim of using BC as a wound dressing material, moisture content, swelling ratio, purity and antimicrobial activity were investigated. Fresh prepared BC membrane was smooth, colorless, jelly alike, and it showed translucence after NaOH treatment. The purity of the cellulosic pellicle reached 98.32%, and it had good water holding capacity (98.02%) and high swelling ratio (69.88%). Antimicrobial activity test showed that BC material had excellent sterilizing efficacy against Escherichia coli and Staphylococcus aureus. The surface of BC membranes was porous network structure observed by scanning electron microscopy (SEM). Infrared spectroscopy (IR) results showed that this membrane belong to bio-cellulose materials. BC displayed higher water content and water holding capacity, as well as higher purity and antimicrobial activity. It has an extensive usage in biomedicine areas.
Study of Hot Compression Behavior of ZK60 Magnesium Alloy at Elevated Temperature
Authors: He Yun Bin , Pan Qing Lin , Liu Xiao Yan , Li Wen Bin
Published: November 2010

The hot compression behavior of ZK60 magnesium alloy was investigated at the temperatures from 523 to 673K and strain rates from 0.001 to 1s-1 on Gleeble-1500 thermal simulator. The results show that flow stress of ZK60 magnesium alloy decreases with the increase of deformation temperature and the decrease of strain rate. The flow stress curves obtained from experiments can be described in four different stages, i.e., work hardening stage, transition stage, softening stage and steady stage. For higher temperature and lower strain rate, the transition and softening stage are less obvious. The onset of dynamic recrystallization (DRX) occurred before the stress peak in true stress-true strain curves. The critical stress characterizing the onset of DRX rises with the increase of strain rate and/or the decrease of deformation temperature. The constitutive equation of ZK60 magnesium alloy during hot compression was constructed allowing for the effect of true strain on materials constants. The predicted stress-strain curves according to the constitutive equation are in good agreement with experimental results.
Dry Sliding Wear Behaviours of Intrinsically Sintered Micro-Arc Oxidation Coatings on Pure Aluminum
Authors: Jiang Yong Feng , Zhang Ying Yue , Bao Ye Feng , Yang Hua Shan
Published: November 2010

Wear behaviours of micro-arc oxidation (MAO) coatings on pure aluminum in a phosphate based electrolyte were investigated. The surface morphology, cross-section morphology and elements distribution of coatings were observed by scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS). Wear test was proceeded with improved pin-on-disk tester under the dry sliding friction condition at load of 10 N. The results show that coatings structure are poly-porous and uniform, the components in the phosphate electrolyte do not participate in the formation of coatings, coatings are oxidized and sintered intrinsically. Wear weight loss of MAO coatings decrease by a factor of 20 in compare with the pure aluminum substrate, and abrasive wear assisted stripping from micro-cracking is predominant wear mechanism.
Tests on High-Velocity Forming of AZ31 Magnesium Alloy by Explosive-Impulsive Pressure（Part II）
Authors: Ruan Li Qun , Hokamoto Kazuyuki , Marumo Yasuo , Yahiro Ititoku
Published: November 2010

As reported in the previous report, increasing velocity by high-speed impulsive energy could improve the formability of AZ31 magnesium alloy. The improvement of ductility of AZ31 magnesium alloys can be observed, which is difficult to observe in usual cold forging techniques. This paper (Part II) is a coutinuation of the reported work in the previous paper. The forming of the AZ31 casting magnesium alloy was done. The hardness distribution of the test specimen was investigated for each experiment, and the microstructures are analyzed. The microstructural results indicate that adiabatic shear bands are formed and the microstructure is changed by the formation of huge amount of fine grained recrystallized structure. Furthermore, solid state is retained in the materials as well as the surface. [1]
Effect of Collocation Ratio of Coarse and Fine WC on Dual Grain Structure Cemented Carbide
Authors: Li Chong Jian , Peng Wen
Published: November 2010

This paper adopts area conversion method to measure the WC grain size manually, sets up a Fibonacci Sequence plane segmentation model based on the statistical data obtained, and studies the effect of the ratio of coarse WC grains to fine WC grains on dual grain structure cemented carbide. It is believed that when SWC (fine) / SWC (coarse) ratio is 0.382, theoretically speaking, the arrangement between WC grains is the tightest. Through investigating the effect of WC grain boundary fusion on its stacking density and contiguity, and the effect of the dissolution and precipitation of WC grains on SWC(fine) / SWC(coarse) ratio, and combining Li Guangyu’s random stacking structure of the cemented carbide theory, it expounds the formation mechanism of the dual grain structure cemented carbide—making a proper amount of fine WC grains fill in the gaps between coarse WC grains so as to increase the stacking density and contiguity of WC grains to the maximum degree, and to separate the accumulated Co-phase layer between coarse WC grains, so that the Co layer more evenly distributes among the fine WC grains.
Research and Realization of the Tool Radius Compensation Algorithm for Material Machining in the CNC System
Authors: Zhang Li Bing , Wu Ting
Published: November 2010

A numerical control (NC) code program is usually generated by a complex CAD/CAM system, which does not include the value of the tool radius compensation. To increase the material machining accuracy within the permissible machining accuracy range, this paper presented the approach of the tool radius compensation for high-speed and high-accuracy material machining. The principle and method of the tool radius compensation were put forward and analyzed, the mathematical model of the tool radius compensation was deduced according to the correlative factors, and the algorithm of the tool radius compensation was constructed for high-speed and high-accuracy. The simulative and experimental results verified the feasibility and validity of the proposed approach.
Multiscale Simulation of Uniaxial Tension Deformation for Single Crystal Cu under Various Crystallographic Orientations
Authors: Liang Ying Chun , Pen Hong Min , Bai Qing Shun , Hu Xing Lei , Wang Zhi Guo
Published: November 2010

In order to investigate the mechanical properties of single crystal Cu nanorod with preset defects, the multiscale unixial tension simulation models of nanorods with two different crystallographic orientations are established. In two orientations, the dislocations are emitted firstly from the notch tip. The results show that the defect evolution, stress-strain curves and train energy vary with different crystallographic orientations. In setup, the deformation is ductile mode and it is fracture fashion in the setup.
Control of PLC for Paving Stock Mechanism of New-Type Machine Tool about Rapid Prototyping Manufacturing for Ceramic Parts
Authors: Gao Dong Qiang , Tian Zhen Ya , Zhang Fei
Published: November 2010

With the development of the rapid prototyping manufacturing for ceramic parts, it is possible to shorten the manufacturing period of ceramic parts and improve the enterprise’s productivity efficiency. The development situation of the machine tools about rapid prototyping manufacturing for ceramic parts was introduced. A new-style device about rapid prototyping manufacturing for ceramic parts, which is based on the technology of laminated coalition and rapid concrete prototyping for ceramic parts, is designed. The basic constitutions, technical processing and working principle of the paving stock mechanism of the device have also been described. The PLC (programmable logic controller) is applied in the paving stock mechanism for controlling and runs well, which meets the requirements of automatic manufacturing for ceramic parts and improves the efficiency.
Development and Application of Control Model for Semi-Steel Steelmaking
Authors: Liang Xin Teng , Chen Yong , Zeng Jian Hua , Li An Lin , Li Gui Jun , Yang Sen Xiang , Li Qing Chun
Published: November 2010

According to the actual characteristics of semi-steel steelmaking of PZH steel, a static model for prediction of the oxygen blow amount and consumption of auxiliary material is established, and an end-point prediction model based on carbon content and temperature of sublance is given. This paper introduced the calculating principle and basic structure about above two models detailed. The results show that, the static model has certain accuracy and reliability of these models are illustrated by actual application.The static model might provide immediately the predicting optimum auxiliary material amount and the oxygen blow amount for operator, which direct the operation in time. The end-point prediction model might give real time prediction for the carbon content and temperature on BOF Endpoint, which has high hitting ratio.
Investigation into AZ31 Sheet Metal Deep Drawing Process at Elevated Temperature
Authors: Wang Peng Cheng , Wu Pei , Yue Zhi Yong
Published: November 2010

In this paper, mechanical properties of unidirectional hot tensile tests of 3mm thick AZ31 magnesium alloy sheet metal are researched at elevated temperatures and under different tensile speeds. In this basis, thermal deep drawing of cylinders tests for 3mm thick AZ31 magnesium alloy sheet are investigated at elevated drawing temperatures, different drawing speeds and so on. Thermal deep drawing performance showed that set pieces better when elevated temperature and drawing speed range are appropriate to deep drawing.
Finite Element Analysis for Comprehensive Residual Stress of 7075 Aluminum Alloy Thick Plate
Authors: Li Hai Yan , Zhang Yi Du , Zhang Hong Wei
Published: November 2010

Based on “physical field coupling” finite element method, the generation of residual stress and interactive coupling effect were analyzed during the forming process of aluminum alloy thick-plate. Therefore, comprehensive residual stress generated from rolling, quenching and stretching was obtained. The finite element model was proved effective by comparing the results of simulation and experiment. Results show that percent reduction has significant influence to the distribution and magnitude of rolling stress; There is a coupling effect between rolling stress and quenching stress, which represents a basic state; Furthermore, after stretching the distribution of coupling stress remains, but the value reduces greatly; The residual stress has got the minimum, when stretching is near 3%.
Technical Research of Friction Stir Welding Repair in Aeroplane Aluminium Alloy Damage
Authors: Hu Jin , Ding Li Li , Guo Bi Xin , Fang Wen Peng
Published: November 2010

This article briefly introduces traditional repair technical defects of the aeroplane aluminium alloy and the current situation of FSW. It demonstrates FSW technique feasibility using for aeroplane repair, and makes a initial research some damage forms adopting FSW repair technique, such as cracks, blow holes, and gaps, and so on. Besides, it indicates several development directions on the large-scale application of FSW in aeroplane repairing.
Investigation on Cooling Slope and Conventional Stir Cast A356/Al2O3 Metal Matrix Composites
Authors: Budiman Hendri , Omar Mohd Zaidi , Jalar A. , Syarif Junaidi
Published: November 2010

A356/Al2O3 metal matrix composites produced by means of conventional stirring and cooling slope casting have been investigated and their microstructures were compared. The microstructure of conventional stirring cast samples are fully dendritic in contrast to equiaxed morphology of the cooling slope cast samples. The image analysis was carried out to characterize the effective volume percent of Al2O3 particles in the ingot, and the shape factor and the size of α-Al crystals. The cooling slope casting produces higher effective volume percent, having microstructures with smaller α-Al crystal size and a greater shape factor than the conventional stirring.
Study on Modeling and Simulating of Spiral Bevel Gears
Authors: Zhang Fa Min , Xiang Chang Le , Liu Hui
Published: November 2010

Based on the theory of space meshing, the paper deduces the equation of tooth traces on the surface of the pitch cone of Gleason spiral bevel gears. The equation of tooth traces on the surface of the cone with given cone angles would be gained consequently. The 3-D models of a pair of Gleason spiral bevel gears used in the transmission system of a type of vehicle was built by the way of Pro/E parameter design software and spherical involutes function was adopted in this progress. The kinematical flank interference inspection of the gear pair was made and the satisfying gear pair was obtained through the adjustment of tangent modification coefficient. The work in this paper provides conditions for much more FEM analysis of Gleason spiral bevel gears.
Finite Element Simulation and Experimental Verification of Hydropiercing-Bend Process
Authors: Wu Zhi Gang , Li Shu Hui , Zhang Wei Gang
Published: November 2010

In recent years, hydropiercing technique has been used widely. In this work, its special type of hydropiercing-bend is simulated using Rice and Tracey ductile criterion based on VUMAT of ABAQUS/Explicit and verified by experiments. Hydropiercing-bend processes with different slope angles of chamfer are discussed to predict the ultimate quality. It is shown that the angle of chamfer should be less than 70º for this kind of material and technical condition in order to make the slug attached with the tube blank.
Influences of Sintering Process on the Microstructure and Mechanical Behavior of ZrO2 Nano-Composite Ceramic Tool and Die Material
Authors: Yi Ming Dong , Xu Chong Hai , Zhang Jing Jie , Jiang Zhen Yu
Published: November 2010

A new ZrO2 nano-composite ceramic tool and die material was prepared with vacuum hot pressing technique. The effects of sintering parameters on the nano-composite ceramic tool and die materials were studied. The results indicated that the mechanical properties of ZrO2 nano-composite ceramic tool and die material with the additions of TiB2 and Al2O3 are higher than that of the pure ZrO2 ceramic material. Sintering at 1100 for 120min could improve the density and mechanical properties of ZrO2 nano-composite ceramic material. The flexural strength, fracture toughness and hardness with the optimum sintering parameters can reach 878MPa, 9.54MPa•m1/2 and 13.48GPa, respectively, obviously higher than that with non-optimum sintering parameters.
The Research on Wear Performance at Elevated Temperature of Ni-Based Infiltrated Layer
Authors: Yang Gui Rong , Sun Xian Ming , Zhou You He , Song Wen Ming , Ma Ying , Lu Jin Jun , Hao Yuan
Published: November 2010

The Ni-based alloy was used as raw materials to fabricate the surface infiltrated layer with 1-4mm thickness on cast steel substrate through vacuum infiltrated casting technology. The microstructure indicate that the infiltrated layer included surface melting and sintering layer, metallurgical fusion layer and diffusion layer. Wear property was investigated under different temperature conditions such as room temperature, 150°C, 300°C and 450°C. The results indicated that the abrasion volume of infiltrated layer was near to third of that of substrate, and it was nearly half of the substrate. This illuminated that the infiltrated had excellent wearable property. The adherence and fatigue abrasion was the main wear mechanism under low temperature. Oxidation abrasion and adherence dominated the wearing process under elevated temperature.
Numerical Study and Experimental Investigation of Solidification Phenomena in Semi-Continuous Casting of Bronze
Authors: Hao Jing , Grasser Monika , Wu Meng Huai , Ludwig Andreas
Published: November 2010

In semi condinuous casting of technincal bronze alloys homogenuous microstructure is very important for the assurance of material properties. The improvement of the knowledge about both, thermodynamics of the ternary system Cu-Sn-P and the solidification process is of main interest for the involved industry. To describe solidification of these alloys, the ternary system Cu-Sn-P in the Cu-rich corner is experimentally investigated. DSC measurements, diffusion and annealing experiments have been performed and compared with computational thermodynamics based on the Calphad approach. The so defined thermodynamic information is coupled with solidification simulation. For this, CFD calculations are done with a two phase solidification model including mass, momentum, energy and concentration transfer and applied to semi-continuous casting of technical Bronze alloys. The predicted macrosegregation pattern is in good qualitative agreement with experimentally observed result.
Sideways Movement of Strip in In-Plane Roll-Bending Process with Conical Rollers
Authors: Li Zhi Jun , Yang He , Li Heng , Liu Jing
Published: November 2010

As a result of unequal reduction, the sideways movement of the strip at the entry is occurred in in-plane roll-bending process with conical rollers. This will reduce the shape quality of the formed ring. To control the sideways movement, FE simulations with applying unilateral and bilateral guide planes are carried out by employing ABAQUS/Explicit code. The results show that, the strip moves towards the bottom end and scratches with guide plane at the trailing end if applying unilateral guide plane; the sideways movement can be controlled effectively with circularity of 0.993 and maximum deviation ratio of 12.5% for the formed ring if applying bilateral guide planes.
Effects of Heat Treatment on the Interfacial Structure of Nickel-Aluminum Coating Composites
Authors: Issariyapat Ammarueda , Swangsak Panu , Boonyongmaneerat Yuttanant , Visuttipitukul Patama
Published: November 2010

Nickel(Ni) layer was applied to the surface of pure aluminum(Al) by electrodeposition for 15 minutes using a direct current (DC) condition at 0.13 Acm-2. Heat treatment was employed subsequently for 1, 2.25 and 4 hours at the temperatures of 600 and 650oC, which are below and above the eutectic temperature of Al-NiAl3, respectively. All samples were characterized by OM, SEM, EDS and GIXD. DTA was also performed to study heat release in the reactions. After heat treatment at 600oC, the specimens exhibit the non-uniform formation of Ni2Al3 and NiAl3, even after 4 hours of heat treatment where local melting possibly occurs due to the exothermic heat of formation. In contrast, owing to fast interdiffusion of Al and Ni as assisted by a liquid phase formation, multi-layer of Ni2Al3 and NiAl3 was uniformly formed along the interface of the specimens heat treated at 650oC.
A Small Amount of Alloying Additions Applied in Hot Dip Galvanizing
Authors: Zhou Rong , Fan Yun Ying , Jiang Ye Hua , Liu Yao
Published: November 2010

Investigating the changing quality of galvanized parts when pure zinc plated with other alloying additions. In the procedure of hot dip galvanizing, when pure zinc plated without other alloying additions, the corrosion resistance of zinc coating is poor, meanwhile the bath surface will produce a number of zinc dross, zinc ash, and this phenomenon will cause a waste of zinc, resulting in an increase in product costs, and the surface of product is relatively dark, the brightness is not enough, whilst sometimes even form a phenomenon of the formation of the Pan-color on the surface of the galvanized parts. However, when a proportion of aluminum or rare earth elements is added into melting zinc, the corrosion resistance of coating will be improved and much better than pure zinc galvanized parts;as the decrease of zinc ash, the cost will be reduced;synchronously the limititation of superficial quality above-mentioned will be improved. Via evaluating the superficial quality of galvanized parts and the corrosion resistance, the whole performance will be significantly improved when 0.5% aluminum and 1.5% rare earth elements is added into melting zinc.
A Study on Design Methodology and Concurrent Engineering on Scroll Vacuum Pump
Authors: Wang Li Cun , Chen Jin , Zhang Xian Ming
Published: November 2010

The concept of concurrent engineering is that designers, manufacturing engineers and all other members of the new product development team can work simultaneously or co-operate closely to avoid redesign and other problems at a later stage. The finite element method/FEM is the kernel of the approach. It enables the designed outputs to be optimal, robust and efficient so that high quality products could be achieved at a low cost in the shortest delivery time. The scroll components work in a high pressure and high temperature environment, which results in the deformation of the scroll wall. If the deformation was too great the vacuum pump would fail and would have to be redesigned and remanufactured. The designer can seek optimization under the limitations imposed by the displacement or stress of the scroll wall. The FEM and optimization can evaluate the deformation due to the cutting force and compensate accordingly.
Numerical Simulation of Magnetic Fluid Lubrication
Authors: Wang Li Jun , Yan Xiao Kang , Li Fei Hu , Dong Zi Xin
Published: November 2010

This paper was concerned with theoretical analysis and the static characteristics of the journal bearing lubricated with magnetic fluid. A general Reynolds equation based on magnetic fluid model is obtained, which can be easily extended to other non-Newtonian fluids and this equation can provide theoretical basis for hydrodynamic analysis of magnetic fluid journal bearings. For the case of static loaded magnetic journal bearings, the influence of magnetic fluid effects on the lubrication performance is studied under various eccentricity ratios, magnetic intensity and concentration. The numerical results show that: with the increasing of concentration, the bearing capacity is obviously increased; the increase magnitude is larger when the eccentricity ratio is large. Under the effect of magnetic field, the bearing capacity increasing with the increasing of magnetic field intensity. When the eccentricity is small, the side leakage is highly decreased. It can be completely eliminate by appropriately designing the bearing geometry and the magnetic field which can’t be existed in normal journal bearings.
Simulation of Gravity Effects on Bulk Crystal Growth with Effects on Undercooling
Authors: Lu Ming Fang , Chuang Shu Hao , Lee Hsing Juin
Published: November 2010

The effects of gravity and kinetic undercooling upon the melt/crystal interface in a vertical Bridgman-Stockbarger crystal growth system by numerical simulation. Thermal transport, melt convection and kinetic undercooling are simulated by two-dimensional transient calculations. Time evolution of the centerline interface location difference is tracked. This study then compares and discusses the results among the different gravitational acceleration. We also investigate the effects of the undercooling on the interface.
Simulation of Thermal Stress and Hot Tearing in Engine Block Casting
Authors: Liu Jin Xiang , Liao Ri Dong
Published: November 2010

Using finite element method, a numerical simulation is presented for engine block casting. The filling process analysis provides an accurate initial temperature field to the thermal stress and hot tearing investigations; meanwhile, it is useful in prediction of cooling shut. The thermal stress distribution after solidification of the casting is solved. To assess the hot tearing, the RGD criterion is adopted. Both hot tearing indicator and thermal stress can be used to estimate the susceptibility of hot tearing. The results can offer a reference to casting parameter design for engine block.
Distribution and Variation Characteristics of Temperature in Inertia Friction Welded Inconel 718 Joint
Authors: Bu Wen De , Liu Jin He , Xu Xiao Ling , Wu Wei
Published: November 2010

The temperature evolution in inertia friction welded Inconel 718 joint was measured by means of embedding thermocouples in specimens. The spatial distributions of temperature in the axial and radial directions of weldments were obtained and the varying characteristics of the temperature distributions were analyzed. The results indicate that the heating rate during the inertia welding process decreases gradually. The temperature distribution in the radial direction of weldment is uneven and the temperature rises gradually with the increase of distance from the center. But the relation between the temperature and distance is nonlinear. In the axial direction, the shorter the distance from the initial friction surface is, the bigger the rate of temperature increment becomes and the higher the peak temperature and the temperature gradient are. Meanwhile, the longer the distance from the initial friction surface is, the later the peak temperature appears and the longer the delay time gets. Moreover, the results of microhardness testing in a welded joint prove that the measurement of temperature in this study is reliable.
Thermal Analysis and Optimization of MEMS Temperature Sensor for Food Detection
Authors: Gong Yan Jue , Zhao Fu , Xiang Hui Yu , Zhang Li
Published: November 2010

In order to improve the sensitivity of MEMS temperature sensor, this paper proposes an efficient and robust structural optimum design method for the sensor structure. Based on thermal analysis of software ANSYS, the thermal deformation and distribution of temperature field can be obtained clearly. A predictive model for thermal deformation is established using artificial neural network and the sample for neural network model is designed by using orthogonal experimental method. In the model, the structure parameters of sensor are treated as design variables and the objective is to obtain the maximum deformation. Optimization of structure parameters for sensor was conducted by introducing artificial neural network prediction models into genetic algorithm. The results indicate that the optimization method based on artificial neural network and the genetic algorithm is feasible for improve the sensitivity of chemical sensor.
Study on the Mechanism of Prolonging Service Life of Tap in Low Frequency Torsional Vibration Tapping
Authors: Han Feng Qi , Li Zhi Zun , Zhang De Yuan
Published: November 2010

The mechanism of prolonging service life of tap in low frequency vibration tapping was studied from two aspects of the reduction of wear and the insensitivity of the passivation of tap. Repeated cutting and separate type boundary lubrication improved the contact and lubrication status on rear face of tap. On the one hand, it greatly reduced the wear of rear face the tap, on the other hand, it markedly decreased the passivation sensitivity of tap to blunt radius and flank wear. With the interaction of two factors mentioned above, the service of life was prolonged greatly by low frequency vibration tapping.
Stress Analysis of Sheet Metal Vibration Incremental Forming
Authors: Cai Gai Pin , Zhu Ning Yuan , Wen Na
Published: November 2010

As a non-homogenous force stresses during incremental forming, sheet metal easily tended to instability, and some defects, such as deposition, wrinkle and fracture, would appear. If the vibration technique was combined the incremental forming process, its deformation mechanism would be different from that of the old process, and sheet metal deformation quality was also risen. Then some mechanical equations were built by force analyzed on element in local contact zone of die head forcing down. According to reasonable hypothesis and simplified, the equations were solved. Some stress-time curves of the element were obtained by given process parameters, vibrational parameters and time parameters. It is shown from analysis that stress variety of the element is closely related to amplitude, frequency and forming angle, effect of sheet metal vibration incremental forming with high frequency vibration is more superior than that of with low frequency vibration; only when vibrational parameters are reasonably matching technical parameters, the effective vibration incremental forming can be obtained.
Effect of Substrate Temperature on Structure and Mechanical Properties of ZrN Coatings
Authors: Qi Zheng Bing , Huang Ruo Xuan , Zhu Fang Ping , Sun Peng , Wang Zhou Cheng
Published: November 2010

The effect of deposition temperature on microstructure and mechanical properties of ZrN coatings fabricated by DC magnetron sputtering was investigated. X-ray diffraction, scanning electron microscope, nanoindentation and scratch test were applied to characterize the ZrN coatings. The results show that with the increasing of substrate temperature the preferred orientation of the coating changed from (111) to (200), the ZrN crystalline phase almost disappeared at 600 resulting from nitrogen loss and the formation of ZrO2 phase. From 50 to 450 , the coatings showed columnar structure, and at 600 the columnar disappeared, presenting equiaxed structure instead. The hardness of coatings showed few significant variations under 450 , and at 600 the coating hardness dropped for the low crystallinity and ZrO2 phase softening. The substrate-coating adhesion decreased with the increasing of temperature before 450 , and then followed by an elevation at 600 .
Computational Analysis for Dynamic Characteristics of Drilling Shaft System in Deep Slot Hole Drilling
Authors: Kong Ling Fei , Li Yan , Lu Yan Jun
Published: November 2010

In this article, the nonlinear dynamic responses of drilling shaft system with hydrodynamic forces of cutting fluid were analyzed in deep slot hole drilling. A numerical method is presented to observe the states of the drilling shaft system. Using the proposed method, the periodic orbit of the drilling shaft motion and its period are calculated when the design parameters of drilling shaft system are subject to change, then the stability for dynamic responses of the drilling shaft system can be determined by the Floquet theory. According to the physical character of cutting fluid, the variational constraint approach is introduced to continuously revise the variational form of Reynolds equation at every step of iteration process. The nonlinear hydrodynamic forces of cutting fluid and their Jacobian are solved simultaneously without the increasing of computing efforts. The numerical examples show that the scheme of this study saves computing efforts but also is good precision, and can make a good reference for the dynamic design of drilling shaft system in deep slot hole drilling.
FEM Analysis of Failure Process in Thin Film during Wear Test
Authors: Zheng Jin Hua , Chen Ying , Lin Chun Lei , Wei Xin Li
Published: November 2010

The semi-circular parallel cracks appeared on the film surface with the angles of 45 degree to the sliding direction of SiC ball and the delamination of film quickly occurred after cracking by using a “ball-on-disk” type testing machine. Stress distribution before and after cracking in the film was calculated by FEM analysis. The maximum tensile stress existing in the film at the back-contact edge of ball is the reason for the initiation of semi-circular parallel cracks. The tensile stress normal to interface as well as the shear stress along interface appears at crack tip, and the alternate generation of these two stresses is the main reason for the delamination. The longitudinal normal stress σxx and the maximum principal stress σ1 become bigger after cracking, so that the crack propagation is faster.
An Advanced Dynamic Secondary Cooling Control Model for Bloom Castings
Authors: Han Zhan Guang , Zhang Jia Quan
Published: November 2010

For bloom casting, typical quality defects such as midway crack usually occur upon improper cooling control during non-steady casting conditions specially for the production specialty steels,. A key measure to eliminate the defects formation has been presented by the adoption of more sophisticated secondary cooling strategies to balance the surface reheating due to casting speed fluctuation. With the consideration of the complex casting conditions and the characteristics of bloom casters, a dynamic control model for the secondary cooling has been developed in the paper to obtain a reasonable temperature profile and solidification progress for the bloom casting process, which is based on a slice residence time method combined with a multi-level control strategy. The feedback system, based on the difference between the calculated surface temperatures and the predetermined or measured surface temperatures, has been integrated into two-dimensional thermal model. The interlocking protection system between level-1 and level-2 is included in the model together with the data diagnosis and processing. Furthermore, the control model also offers technological interface for the introduction of new steel grades in production and the related modification to the secondary cooling parameters. It is shown from online application that the dynamic control system of secondary cooling for bloom casting is robust during operation and adaptable to any change of real casting conditions. Sound quality bloom castings according to acid etched tests have been obtained from the caster accordingly.
A Novel Process for Magnesium Alloy Sheets Deep Drawing at Gradient Temperature
Authors: Zhang Ai Mei , Zhang Zhi Yuan , Li Qi
Published: November 2010

The sheet metal forming of magnesium alloy is studied. A novel hydro-mechanical deep drawing for magnesium alloy sheets at gradient temperature is proposed on the basis of the study in this domain, the properties of magnesium alloy and the forming characteristics of workpiece in deep drawing. It is indicated that the deep drawing operation should be done in the warm condition and the temperature gradient of workpiece is necessary. The essence why the limited drawing ratio can be improved by means of the new process is demonstrated. The proper temperature gradient can be obtained by the control of the hydraulic during deep drawing operation. Thus the feasibility of the new technology is verified. It plays a solid foundation for solving the forming problem of magnesium alloy sheets and designing the novel setup of hydro-mechanical deep drawing with gradient temperature.
Microstructure and Cavitation-Erosion Mechanism of Laser Cladding NiCrSiB Coating on CrNiMo Stainless Steel
Authors: Zhang Xiao Bin , Chang Xia , Wei Tao , Liu Chang Sheng
Published: November 2010

A Ni-based alloy NiCrSiB laser cladding layer was made on the surface of CrNiMo stainless steel specimens using NiCrSiB powder. Cavitation erosion behavior of the laser cladding layer and the CrNiMo stainless steel was investigated by ultrasonic vibration cavitation erosion equipment The results shown that laser cladding layer has dense microstructure and has metallurgical combination with CrNiMo stainless steel substrate. Because of impact effect of cavities collapse, micro-cracks caused material broke off from samples. NiCrSiB laser cladding layer have better micro-crack propagate resistance property than CrNiMo stainless steel.Laser cladding layer has better cavitation resistance properties because of strengthening effect by precipitated phases such as M23[CB]6、CrB、CrSi、Fe2B、B4C and work hardening effect during cavitation erosion process.
Surface Polishing of Metal Mold Using Wax-Coated Abrasive SiC Particles
Authors: Yang Shie Chen , Mao Tsuo Fei , Huang Hsi Chuan , Tsai Feng Che , Ke Jiuan Hung
Published: November 2010

This study introduces an Abrasive Jet Polishing (AJP) technique using wax-coated abrasive SiC particle to improve the polishing quality of mold surface. The experimental results showed that the surface roughness of EDM machined mold cavity improved by 82% (from 4.23 μmRa to 0.76μmRa) within 90 minutes. Moreover, the parting surface roughness improved by 94.7% (from 1.14μmRa to 0.06μmRa). We show that employing the abrasive jet polishing technique with wax-coated SiC particles, not only the mold surface roughness got a good improvement, but also significantly shorten the polishing time.
Process Control of Injection Molding Based on Multiscale Visualization Methodology - A Case Study
Authors: Cheng Jin , Tan Jian Rong , Yu Jia Hong
Published: November 2010

Multiscale visualization approaches are proposed to efficiently assist designers not familiar with statistical mathematics in determining the optimal process parameter schemes for achieving desired part quality in injection molding, based on which the parameters’ relative importance to part quality and their influence on either single quality index or comprehensive part quality can be visually described by the map of the sum of squared deviations, response surface diagram and distribution map of comprehensive part quality. The proposed visualization approaches are universal for analyzing the effects of process parameters on the quality of any injection-molded plastic parts although the mobile phone cover is utilized as an example in the presentation of our work.
Fuzzy Neural Network Controller Based on Improved Genetic Algorithm for Temperature of Glass Tempering and Annealing Process
Authors: Wang Xiao Kan , Sun Zhong Liang , Guo Sanci , Shen Chao Qun
Published: November 2010

The temperature control of the glass tempering and annealing process has characteristics of time-varying parameters，nonlinear and big lag. It is difficult to meet the expected control effect with the common control method. To solve this problem，this paper puts forward a kind of fuzzy neural network controller optimized by genetic algorithm. First，it uses neural network to construct fuzzy logic system according to the structure equivalence rule，thus the optimization of fuzzy control rules and membership functions can be realized by finding the weight value of the neural network. Then，it uses the improved genetic algorithm to find the global optimum weighted factors with a high speed so to improve the performance of the controller. The simulation results show that the optimized fuzzy neural network controller can obtain an excellent control performance for the nonlinearity system with time- varying parameters and lag.
Tribological Performance Research of Micro-Nano Serpentine Powders Addictive to Lubricant Oil
Authors: Zhang Bo , Xu Yi , Zhang Bao Sen , Xu Bin Shi
Published: November 2010

The serpentine is a kind of phyllosilicates whose crystal structure leads to a tetrahedral-octahedral (TO) structure. Because of its unique crystal structure, micro-nano serpentine powders (MSP) in liquid lubricants can show a good tribological performance, so that lots of scholars had started extensive and in-depth studied on its tribological performance. In this research, the raw material which is Xiuyan serpentine produced from Liaoning province, China, had been made into powders with particle average diameter about 0.5 μm. The friction optimized content of MSP in the lubricant oil was studied and it were examined that the loads’ and friction pairs move velocity’s changes had effect to tribological performance in friction course. The results show that the optimal content of MSP in gasoline engine oil SJ10W-40 is 0.5 mass%, under this condition, friction coefficient can be reduced to 0.03, and the friction-reduction performance can been enhanced by 73.3%, so that the lubrication state is that boundary lubrication changes into mixed lubrication. Disclosing the tribological rule of MSP in lubricant oil under the condition of loads and the move velocity of friction pairs changing, and discovering MSP addictive to lubricant oil can extended friction pairs with high move speed and heavy loads working hours, all that can provide a theoretical basis to promote engineering.
Corrosion Behavior of Different Thermal Spray Coatings and Hard Chromium Electroplating on A286 Super Alloy
Authors: Durul Elif Nazik Atabay , Nurbaş Macid
Published: November 2010

Electrodeposited hard chromium (EHC) coatings have been widely used for improving wear characteristics of engineering tools and components. In the electrodeposition processes, in general solutions containing hexavalent chromium have been used. Hexavalent chromium is classified as a carcinogen compound, which causes health risks if used in production, and environmental problems due to the toxic character of the wastes [1]. In the present study plasma sprayed coatings (aluminum oxide, Co-28Mo-8Cr-2Si, tungsten carbide, chrome carbide) and electrolytic hard chrome coatings corrosion resistances have been compared through electrochemical polarization tests and immersion test in 0.1 N HCl aqueous solution.
Research on the Preparation of Polyferric Silicate Chloride (PFSC) and Application on Algae Wastewater Treatment
Authors: Wang Li Ping , Yan Xiao Fei , Xu Xia , Xu Ai Bin , Gao Nai Yuan
Published: November 2010

A new polyferric silicate chloride(PFSC) was prepared by using sodium silicate, ferric chloride as raw materials, at the same time, its coagulation performance and the influencing factors were observed. The water containing algae was processed by PFSC coagulant and coagulation mechanism were discussed. The results showed that the best reaction time of PFSC preparation was 1h, temperature was 40°Cand Fe/Si mole ratio was 1. The removal efficiencies of chlorophyll a and turbidity were 82.40% and 94.97% respectively at 14mgFe•L-1 of dosage. Coagulation mechanism of PFSC is considered as the cooperation of oxidization/adsorption/charge-neutralization, adsorption-bridging and sweeping, which is the effect of silicic acid, iron and iron hydrolysate on the suspended particles in wastewater.
Surface Temperature Monitoring of Casting Strand Based on CCD Image
Authors: Zeng Zhi , Zhang Jia Quan , Liu Yuan
Published: November 2010

Continuous casting process is used for the solidification of molten steel into semi-finished shapes. Due to lack of reliable sensors online, manual monitoring was often essential to cooling control, which was time consuming and inefficient. This paper proposes an approach to automatically monitor high-temperature casting strand based on radiation thermometry, with the help of CCD (charge coupled device) camera and digital image processing technology. The bicolorimetric temperature measurement method is introduced in detail, as well as the working principle of CCD. Programs developed by Visual C++ 6.0 complete the acquisition, processing, calculation and visualization of casting strand image data. Besides, some experiment of temperature test was carried out for bloom casting (section size of 260 mm×300 mm) in a domestic steel plant so as to verify the monitoring model. Consequently, the purpose for monitoring casting strand is achieved, which is beneficial to cooling control in the process of continuous casting.