bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling and Optimization of Vibration Amplitude in Turning of Ti-6Al-4V Using Response Surface Methodology
Authors: Amin A.K.M. Nurul , Arif Muammer Din , Sulaiman Syidatul Akma
Published: November 2012

Chatter is detrimental to turning operations and leads to inferior surface topography, reduced productivity, dimensional accuracy, and shortened tool life. Avoidance of chatter has mostly been through reliance on heuristics such as: limiting material removal rates or selecting low spindle speeds and shallow depth of cuts. But, modern industries demand increased output and not steady operational limits. Various research efforts have therefore focused on developing mathematical models for chatter formation. However, as yet there is no existent model that meets all experimental verification. This research employed a novel technique based on the synergy of statistical modeling and experimental investigations in order to develop an effective empirical mathematical model for chatter amplitude and to subsequently find optimal machining conditions. Ti-6Al-4V, Titanium alloy, was used as the work-piece due to its increased popularity in applications related to aerospace, automotive, nuclear, medical, marine etc. A sequence of 15 experimental runs was conducted based on a small Central Composite Design (CCD) model in Response Surface Methodology (RSM). The primary (independent) parameters were: cutting speed, feed, and depth of cut. The tool overhang was kept constant at 70 mm. An engine lathe (Harrison M390) was employed for turning purposes. The data acquisition system comprised a vibration sensor (accelerometer) and a signal conditioning unit. The resultant vibrations were analyzed using the DASYLab 5.6 software. The best model was found to be quadratic which had a confidence level of 95% (ANOVA) and insignificant Lack of Fit (LOF) in Fit and Summary analyses. Desirability Function (DF) approach predicted minimum vibration amplitude of 0.0276 Volts and overlay plots identified two preferred machining regimes for optimal vibration amplitude.
Inserts Selection for Intermittent Turning of Magnesium Pieces
Authors: Rubio Eva María , Valencia José Luis , Carou Diego , Saá Adolfo J.
Published: November 2012

The present work shows an experimental study for selecting the best tools to use in the intermittent turning of pieces of UNS M11917 magnesium alloy under low performance conditions based on the surface roughness. Namely, two types of tools are considered: one, specific for non-ferrous materials, and the other, for materials usually combined with the magnesium to form hybrid parts such as titanium or steel. In order to carry out this study, a combined design of experiments (DOE) L4x32 is established. Concretely, the factors that are taken into account in the design, in addition to the type of tool, are considered the next ones: depth of cut, feed rate, spindle speed, quantity of lubrication, type of interruption, and measurement zones of the surface roughness in terms of the measurement length and of the measurement generatrix. Obtained data are analysed by means of the analysis of variance (ANOVA) method. In this case, feed rate is the most influential factor on the variability of surface roughness followed, although at a large distance, by: type of interruption, interaction feed rate-quantity of lubrication, type of tool, quantity of lubrication, interaction type of tool-type of interruption and spindle speed. As conclusion, it is possible to affirm that, in general, the surface roughness is slightly lower when using non-ferrous tools than when using the other types tried.
Finite Element Mesh Model Analysis and Model Information Transform Method in Casting Simulation Process
Authors: Rao Lei , Zhu Lian Bing , Hu Qi Yao
Published: November 2012

High quality mesh model is the premise and key condition to get accuracy numerical simulation results in casting process. However, it is usually difficult to build effective mesh model by professional casting simulation software ProCAST if solid model is too complex. Finite element mesh model transferring method has been introduced in this paper to transfer high quality mesh model into ProCAST by element imaging algorithm. With the help of the powerful meshing function of Pro/E, UG and ANSYS, the nodes and elements information has been picked up and image to new mesh model which is compatible with ProCAST. By this way, high quality mesh model can be introduced into casting process numerical calculation easily. It provides an effective and efficient way for the complex casting finite element mesh model.
Study of the Machining Principle and Influencing of ELID Grinding on SiC
Authors: Xiao Qiang
Published: November 2012

The hardness of SiC single crystal is very closer to that of diamond, which makes it greatly difficult to process SiC single crystal. It is usually machined by lapping, but this technique requires a long machining time, resulting in low productivity, So we examine the possibility of ELID grinding in SiC single crystal. Results show that with the use of ELID, mirror surfaces can be achieved with high efficiency.
Preliminary Study on the Rotational Indexing Machining Technology of Straight Bevel Gear
Authors: Li Jia , Meng Wen , Shi Jiang
Published: November 2012

Aiming at the disadvantages of intermittent indexing in the existing straight bevel gear machining methods, a continuous indexing machining method is proposed based on the principle of cycloid rotational indexing. The principle of rotational indexing machining of straight bevel gear is explained by the mathematical method of the space curve approximating straight line. On this basis, the mathematical models of forming motions are established. The relations of useful parameters are built with these models, and then the cutting point trajectory is obtained. The parameters are adjusted according to the approximation straightness of curve segment to generatrix on tooth surface. By means of calculation and numerical simulation of an example, the feasibility of the rotational indexing machining method for straight bevel gear is proved.
Experimental Study on the Possibilities to Decrease the Coefficient of Restitution after Impact
Authors: Penchev Todor Nikolov , Altaparmakov Ivan Lyubomirov , Karastojanov Dimitar Nedelchev
Published: November 2012

Technological processes such as forging, die forging, pile driving, etc., are realized as a result of a collision between two bodies. The bodies’ rebound after the collision takes place due to the use of part of the energy of the hit for their elastic deformation. The paper presents results from an experimental research on the possibilities of the decrease of rebound, by the use of an additional force during the hit. A laboratory test-stand is described in which an additional force is created by the use of a cold rocket engine, working with compressed air.
Practice and Analysis of the Technology of Direct-Tapping
Authors: Chen Yong , Liang Xin Teng , Zeng Jian Hua , Li Gui Jun , Yang Sen Xiang
Published: November 2012

Steelmaking Plant of PZH Steel improves the hitting ratio of independent converter model, by optimizing the terminal controlling model of molten steel, stabilizing the charging load in BOF, accelerating the turnover rapid of ladle, improving the quality of semi-steel into the furnace and optimizing the management of production organization. So the ratio of the direct-tapping is improved and increases to more than 50% now from 25% on average in 2011.
Simulation and Analysis of Stroke-Controlled Tube Hydroforming by Finite Element Method
Authors: Gao Zhen Li , Yang Jian Wei , Dou Yun Ping , Liu Jian Jun , Tang Bo Yan , Yuan Mei Xia
Published: November 2012

Hydroforming is a new deforming technology , Many of numerical analyzes of bulge forming processes have concentrated exclusively on the behavior of the deforming tube . Finite element models have been developed to simulate stroke-controlled tube , with particular emphasis on the state of stress and deformation of the work piece in the paper . The effects of using internal pressure alone and combined internal pressure and axial compressive load were investigated and it was found that the development of the location of maximum strain was dependant on the type of loading used.
Steel-Concrete Bond Deterioration under Repeated Loading for Different Confinement Levels
Authors: Valente Marco
Published: November 2012

This paper presents the results of experimental tests and numerical analyses concerning the influence of repeated cyclic loading and reinforcement confinement on bond between steel rebar and concrete. Experimental tests of push-pull type were carried out at the Politecnico di Milano on concrete specimens provided with a steel cage of longitudinal bars and stirrups, and reinforced with a single steel rebar. The experimental tests were conducted under monotonic and repeated loading history. Bond strength degradation was observed due to repeated cyclic loading. Detailed three-dimensional finite element models of the specimens were developed to reproduce laboratory tests and parametric analyses were performed to provide a better understanding of the experimental results. The numerical analyses showed good agreement with the experimental results and confirmed that the applied repeated loading history caused significant bond deterioration. High values of reinforcement confinement enhanced bond strength and delayed the onset of bond deterioration.
Test and Analysis on Anti-Penetration Performance of Ceramic Multi-Layer Composite Medium
Authors: Wang Kai Seng , Dai Ge Lin , Geng Guang Long , He Guo Liang
Published: November 2012

Do tests to study anti-penetration performance of ceramic multi-layer composite medium structure with simulation method of a 1:5 shrinking model and analyze its mechanism. The result shows that ceramic composite layers, which are composed by glass reinforced plastic materials and ceramic materials, obviously consume quality and kinetic energy of penetrating shot body. And the smaller biting angle of shot body is, the more serious damage of structure will be.
Microstructure of Al-Li Alloy Electron Beam Welding Joint after Post-Weld Heat Treatment
Authors: Wang Shao Gang , Yu Kuang , Luo Chuan Xiao , Xing Li
Published: November 2012

Heat treatment was carried out to the 1420 Al-Li alloy electron beam welding (EBW) joints after welding, and the microstructures of welded joints are analyzed systematically before and after post-weld heat treatment (PWHT). The observation of joint microstructure demonstrates that the grain morphology of weldment changes from equiaxed dendrites in as-welded (AW) condition into equiaxed grains after PWHT, and that the fine strengthening phases precipitate within the grain. The XRD analysis of phase constituent and TEM observation of weldment indicate that the main strengthening phases in 1420 Al-Li alloy weldment are spheroidal δ′(Al3Li), β′(Al3Zr) and rod-like T(Al2MgLi) after PWHT. Furthermore, the δ′ phase precipitate free zone (PFZ) is found along the grain boundary. The scanning observation of joint fracture shows that Al-Li alloy EBW joint presents the characteristic of transgranular ductile fracture in AW condition. After PWHT, the Al-Li alloy welded joint presents the pattern of intergranular fracture. The variation of fracture mode is related to dispersed precipitation of δ′ phase and the formation of PFZ at the grain boundary in weldment after heat treatment.
Analysis of Thermal Stress during of Twin-Roll Casting of Magnesium Alloy
Authors: Zhang Yu Cheng , Han Tian Yang , Jiang Zheng Yi , Wei Dong Bin
Published: November 2012

The process of twin-roll casting including pouring, solidifying, rolling and cooling can be accomplished in a very short time. Consequently, some important process parameters in the twin-roll casting that are difficult to be obtained in experiment can be acquired using numerical simulation. In this paper, a numerical simulation based on a 2D finite element model of vertical twin-roll strip casting of magnesium alloy has been conducted, and the thermal stress fields are significantly discussed. The influences of key process parameters consisting of submerged nozzle depth and nozzle spray angle have been studied. The thermal cracks on the surface of the strip are analysed according to the thermal stress distribution.
Study on Hot Stamping Process of Cannonball Body Semiproduct Based on Numerical Simulation
Authors: Qi Peng Fei , Liu Gui Hua , Wang Wei , Huang Xi Na , Qiu De Hua
Published: November 2012

Using the finite element simulation software Deform-3D , the forming characteristics of pressing, cupping and shell ironing of the thick-walled cannonball body semiproduct were analyzed, and the parameters of shell ironing was optimized. The results show that the load increases sharply at the end of the pressing, while the bottom corner of the billet and the boss are not well formed, which can be finished at the end of cupping; Due to friction, the metal closed to the end face of the punch dose not deform during the cupping process, but rigidly moves with the punch. This part without deformation of the billet is called deformation viscous zone. As the cylinder wall of the billet bears axial tensile stress during the shell ironing, deformation at the bottom and necking would occur easily undercondition of bad lubrication and large deformation. When die-entrance taper is 15º, the workpiece have homogeneous deformation, low axial tension stress and forming load. The forming load of shell ironing can be effectively reduced by good lubrication for die.
Mechanism of Nanofibre Fabrication by Meltblowing
Authors: Nayak Rajkishore , Padhye Rajiv , Arnold Lyndon , Kyratzis Ilias Louis , Truong Yen Bach , Peeters Gary , Nichols Lance , O'Shea Mike
Published: November 2012

Fabrication of nanofibres has become a growing area of research because of their unique properties (i.e. smaller fibre diameter and higher surface area) and potential applications in various fields such as filtration, composites and biomedical applications. The mechanism of nanofibre fabrication by meltblowing process with the injection of different fluids (such as air and water) has been investigated in this paper. In the meltblowing equipment the fluids were injected at a vent port along the extrusion barrel, for the fabrication of nanofibres. The injection of water resulted in better fibre morphology compared to the injection of air. Nanofibres were fabricated by the drafting action of the high-velocity flow of the heated air and the steam in the extruder. The fibres collected were straight prior to the fluid injection and coiled fibres were collected with the injection of fluids. Three types of fibres such as ribbon shaped, fused and branched fibres were obtained in addition to the circular fibres.
Automatic Welding Method and Main Parameters Calculation of Tube Connected Five-Star Feet
Authors: Jiang Wu Ji
Published: November 2012

In view of the situation that low quality and high cost of manual welded five-star feet, this paper proposed a new method to weld five-star feet. The method is compositing linear motion of welding torch and rotary motion of the workpiece to realize 3d welding track. After mathematic analysis and detailed calculation, the welding trajectory equation is obtained, and the speed matching relation between the welding torch and the workpiece is gained too.
Optional Roughing Tool Diameter Sequence Determination for Pocket: Integrated Geometric Characteristics and Processing Rules
Authors: Rao You Fu , Zheng Guo Lei , Du Bao Rui , Zhai Nan , Chu Hong Zhen
Published: November 2012

Both to determinate the maximum diameter of cutting tool for a pocket, which is a common operation in CAM and feature representation, and to search an Optional Cutter Diameter Sequence (OCDS) for roughing, we introduce an approach using the Integrated Geometric Characteristics and Processing Rules (IGC&PR) algorithm. In IGC&PR algorithm, geometric characteristics includes accessible section (AS) calculated with rolling disk motion approach, ASs conjunction and narrowest convex hull for AS, also processing rules contains first cutting into condition and three AS index. Besides, the implement of this algorithm just needs simple geometric and mathematical calculation such as points, lines and vectors, rather than complex intersection computation and loop construction, which are needed in traditional methods (e.g., Offset and Voronoi Diagrams). As well, the AS computation can be used for machining cell building in further application. Finally, two examples are proposed to illustrate this algorithm, and the results show that the IGC&PR is implemented and tested successfully on real-world data.
Molding Plano-Convex Lenses Using a through-Hole WC/Co Plate as the Mold
Authors: Ma Kung Jeng , Chien Hsi Hsin , Huang Jing Kung , Chao Choung Lii
Published: November 2012

This study aims to fabricate the plano-convex lens by glass molding process using a through-hole WC/Co plate as the mold. The effects of temperature, applied loadand arc chamfer on the surface morphology, curvature, and peak height of plano-convex lenses were investigated. The through-hole mold with arc chamfer favors stress release and avoids cracks and surface mark. A higher temperature favors glass material flowing outwards rather than downwards, which results in the molded lens with a smaller curvature and bigger size.
Discussing for a Rapid & Flexible Casting Design Method Based on Modeling, Simulation and Rapid Prototype Machine
Authors: Su Zi Cheng , Wang Chuan Yang
Published: November 2012

Nowadays, customer has more and more requirements of quick product updating. On the opposition side, casting need a long lead time for tooling prepare and qualify. And a necessary test for casting is need. Whether a new casting design or existing casting product revised will take 16 weeks with tradition process. A new method raised in this text can help solute these problems. It calls Rapid & flexible process loop including CAD, CAE and RP. A better cost and time saving can be achieved via it.
Investigation of Vibration and Surface Roughness in Micro Milling of PMMA
Authors: Mohammad Yeakub Ali , Mohamed A. R. , Asfana Banu , Lutfi Mohamed , Fahmi M. I.
Published: November 2012

This paper presents the vibration and surface roughness issue of poly methyl methacrylate (PMMA) workpiece produced by micro end milling using integrated multi-process machine tools DT 110 (Mikrotools Inc., Singapore) with control parameter; spindle speed, feed rate, and depth of cut. The vibration was measured using accelerometer, DYTRAN Instrument and the average surface roughness Ra was measured using Wyko NT1100. The optimum solution for minimum average vibration is 64.3 Hz with spindle speed 3000 rpm, feed rate 2 mm/min, and depth of cut 1.5 μm. However, the optimum solution for minimum average surface roughness, Ra is 0.352 μm with spindle speed 2000 rpm, feed rate 2 mm/min, and depth of cut 1.5 μm. The micro end milling parameters are suitable to machine PMMA to get good precision surface roughness. The analysis revealed that the feed rate and depth of cut is the most influential parameter on vibration during machining process meanwhile for average surface roughness, Ra spindle speed is the most influential parameter.
Tribological Characteristics of Nano Structured Nickel Coatings for Renivating of Extruding Shafts
Authors: Karastoyanov Dimitar , Penchev Todor , Kandeva Mara
Published: November 2012

The methods for wear resistance testing is described and the experimental results for the dependence of the massive wear, wear speed, intensity of wear and wear resistance on the friction road and the time of a contact interaction are obtained. A testing micromanipulator with piezo actuators for measuring the roughness of the surface layer is developed. A methodology for thermographic testing and experimental results for wear and temperature changes in the contact by the wear process of the coatings under dry friction and abrasion is obtained
Simulation of Temperature Field and Thermal Stress Field during Laser Drilling
Authors: Chen Xue Jun , Liu Qi
Published: November 2012

In this paper, the finite element simulation of laser drilling process has been carried out for the nickel alloy DD6. Both the transient temperature field and thermal stress field were computed via the commercial software package ANSYS. Based on the method of dimensional analysis, the dependence of various non-dimensional parameters on both fields was specified and demonstrated in graphical forms.
Research and Design of Laser Scribing Robot Based on Surface Matching
Authors: Xu Zhi Gang , Xu Chun Shu , Ha Le , Zhou Rui Hu
Published: November 2012

As the technology which is commonly used on the cutting large irregular curved sheets has many disadvantages, such as incorrect cutting path, poor cutting accuracy. By analyzing the sheet cutting process, a three-dimensional and five-axis laser scribing robot is developed, which is based on surface matching. This robot can acquire the data of the workpiece surface automatically through the non-contact measurement. The date model can be generated by computer. The matching method is based on curvature and arc length of feature points. By matching data model and ideal model, robot can choose the optimal trajectory for laser cutting. From experimental results, the robot is designed rationally. It can make the scribing path closest to the ideal track and has extensive utility value.
Crack Propagation and Simulation of Thermal Fatigue
Authors: Yu Hui , Zang Xin Liang , Liu Li Gang
Published: November 2012

In this paper, the thermal fatigue damage phenomenon in the comprehensive temperature environment is studied by means of thermal fatigue damage mechanics and FEM technology, the thermal-stress analysis modal under the comprehensive thermodynamic boundary conditions is established, the regularities of distribution of temperature fields, thermal stress fields effected by the comprehensive coupled variables are investigated. According to the modify of material characteristics under the high-temperature alternating thermal impact conditions and the integrated influences of environment, mechanical parameter and material microstructure to the fatigue fracture, numerical modal of thermal fatigue crack initiation and propagation are developed, so the characteristics of thermal fatigue crack propagation are studied, which are verified by the experiments, it is very significant to study thermal damage question of working equipments in the similar conditions.
Twin-Shear Yield Criterion for V-Notches Brittle Fracture under Mixed Modes
Authors: Li Yuang , Liang Yong Cheng , Wang Shi Ming
Published: November 2012

Based on the singular stress field near the V-notch tip and under the two basic assumptions in this paper, twin-shear yield criterion under mixed loading mode I and II is established and the numerical results of the crack angles are calculated by this criterion. In order to verity twin-shear yield criterion ,tension tests are carried out under mixed mode loading by tension testing machine using polymethyl methacrylate(PMMA). The experimental results coincide with the numerical prediction results, which suggests that the twin-shear yield criterion is valid for the V-notch brittle facture.
Study on Crack Detection System of PC Beam Surface
Authors: Guo Chun Hua
Published: November 2012

The surface of PC beam has been covered with cracks and flaws, it causes deficiencies to the safety of system. The inspection system includes inspection equipment and data off-line management. First discuss the theory of data acquisition. Then discuss the data off-line management, which include denoising, enhancement and segmentation. The denoising is based on anisotropic diffusion, which can preserve edge region of higher gradient, and smooth region of lower gradient. The enhancement is according to the characteristics of NSCT different domain, different operators are used in different subbands. The crack segmentation is based on Otsu method, which is according the convexity and concavity of histogram of detected image. The result shows that they can get good performance.
Fatigue Strength of Shaft with Diameter Enlarged Partially by Cyclic Bending and Axial Compressive Loading
Authors: Zhu Xia , Okabe Nagatoshi , Ogi Keiji , Takahashi Manabu
Published: November 2012

This paper experimentally and analytically investigates the fatigue strength and of mechanical damage of the processed shafts. First, we carry out rotary bending fatigue tests and investigate the fatigue strength for smooth specimens, specimen made only using cutting work, and specimens processed using a new plastic working developed originally. Secondly, we measure the Vickers hardness values to investigate strain hardening near the processed part. Finally, we simulate stress and strain distributions of the shaft during the processing using finite element method (FEM) and calculate the stress concentration rate at the notch root of the processed part. Based on the processing experiments and the finite element analyses (FEA), we clarify that the plastic work mechanically does not reduce the fatigue strength of shafts in the processing range.
Constitutive Equations for a Model of Nonlocal Plasticity which Complies with a Nonlocal Maximum Plastic Dissipation Principle
Authors: de Angelis Fabio , Cancellara Donato
Published: November 2012

In the present paper constitutive equations for a nonlocal plasticity model are presented. Elasticity is considered to be governed by local forces so that only the dissipation processes are adopted as nonlocal. Differing from other proposed models in which the isotropic hardening/softening variables are considered as nonlocal, in the present paper the nonlocality is extended in order to include the kinematic hardening behaviour as well, so that both types of hardening (kinematic and isotropic) are considered as nonlocal. The present formulation satisfies a variational condition representing nonlocal maximum plastic dissipation. The proposed constitutive formulation of nonlocal plasticity is thus equipped with a sound variational basis.
A Simple and Sensitive Spectrophotometric Method for the Determination of Trace Ruthenium with its Catalytic Effect on the Oxidation of Rhodamine 6G by KBrO3 in Micellar Media
Authors: Zhou Zhi Rong , Zhang Li Zhen
Published: November 2012

A simple catalytic kinetic spectrophotometric method was developed for the determination of trace Ru (III) in the range of 0.033–1.00 μg/L. The method is based on the catalytic effect of Ru (III) on the oxidation of rhodamine 6G (Rh 6G) by bromate in micellar media. The reaction was monitored spectrophotometrically by measuring the decrease in the absorbance of Rh 6G at 520 nm with a fixed-time method. The limit of detection is 0.010 μg/L Ru (III). The relative standard deviation for the determination of 0.010 and 0.020 μg/25mL Ru (III) was 2.9 % and 2.5 %, respectively. The method was applied to the determination of Ru (III) in some ores and metallurgy products.
Probabilistic Safety Factor of Soil Liquefaction
Authors: Vongchavalitkul Sanguan
Published: November 2012

The most widely used method of liquefaction prediction are perform in deterministic process. The deterministic method according to seismic Chinese code is introduced by Z. CAO et al (2008). The deterministic method used the standard penetration test (SPT) to evaluate the liquefaction of soil. With this method, liquefaction of soil is predicted to occur if the factor of safety(FS), which in the ratio of critical SPT-N value(Resistance) over the actual measurement SPT-N(Load), is less than or equal to one. If the factor of safety greater than one, no soil liquefaction is predicted. Because the significant uncertainties in variable involved in the deterministic factor of safety, the probability method need to use. because the significant uncertainties in the random variables involved, the probabilistic method is needed to predict liquefaction. Probability of failure may be performed in which the liquefaction potential is assessed in term of probability safety factor (central safety factor). The study case is shown that the probabilistic method given the much more information for engineering decision than the deterministic method that given only the safety factor..
Effect of Processing Parameters on Heat Transfer Performance of the Heat-Pipe Grinding Wheel
Authors: Ma Ke , Fu Yu Can , Xu Hong Jun , He Jun
Published: November 2012

Heat transfer performance of the heat-pipe grinding wheel (HPGW) is mainly depended on the heat pipe in the wheel. In this paper, a basal body of HPGW was developed and a heat transfer experiment was performed to study the effect of the parameters of the heat pipe such as liquid filling ratio and rotating speed on the heat transfer performance of the HPGW. Results show that the heat transfer performance decreases if the liquid filling rate is too large or too small under the same heat source intensity and the optimal liquid filling rate is about 35% of the volume inside the heat pipe. The heat transfer performance of the HPGW is enhanced with the increasing of the rotating speed. The analysis of the results also shows that the heat pipe in the HPGW can play a great role on enhancing the heat transfer in the grinding zone with suitable processing parameters.
Analysis of Unsteady State Heat Conduction Performance in Anisotropic Materials
Authors: Su Shun Yu , Huang Qin , Chen Jian
Published: November 2012

The magnitudes of heat flux for both isotropic materials and anisotropic materials can be determined from Fourier’s law. But the mechanism of heat transfer in anisotropic materials is quite different from that in isotropic materials. The thermal conductivities at one point are not equal in all directions for anisotropic materials. The magnitude of heat transfer rate of anisotropic material in one direction is not only relevant to the temperature gradient in this direction, but also relevant to the temperature gradient which is normal to the direction. Basing on one-dimensional unsteady state heat conduction problem in isotropic materials which can be solved by separation-of-variables method, the performance of unsteady state heat conduction in anisotropic materials was analyzed. And the unsteady state temperature field of the anisotropic plane wall was obtained. The results will provide help for the energy conservation of anisotropic materials.
The Two-Scale Finite Element Estimates for Thermoelasticity in Perforated Structure with Boundary Layer
Authors: Deng Ming Xiang , Feng Yong Ping
Published: November 2012

The higher order two-scale finite element errors of the thermoelastic problem in perforated composites with boundary layer are presented, and the two-scale finite element method coupled with boundary layer is built for analyzing the coupling problem. The numerical results show that the basic configuration and the local temperature strongly affect local strains and local stresses.
Necessity Analysis of Tundish Heating Technology Application
Authors: Pan Hong
Published: November 2012

It is beneficial to keep low superheat and constant speed continuous casting with tundish heating technology which can improve the control of molten steel temperature and bloom quality. The application of tundish heating technology at home and abroad is investigated, and the temperature of molten steel and bloom quality in Panzhihua steel are analyzed. On the basis of investigation and analysis, it is necessary to apply tundish heating technology in Panzhihua steel.
Study on Thermal Deformation of Machining Center’s Spindle Box Based on ANSYS
Authors: Zeng Hong Qiang , Zhao Deng Feng , Zeng Guo Ying , Zhang Long
Published: November 2012

Thermal deformation of spindle box is an important factor affecting processing accuracy of the high precision CNC machining center. In order to research the distribution of spindle box’s thermal deformation, physics-environment method of sequential coupling analysis was used to analyze thermal-structure coupling with the finite element analysis software ANSYS. The results show that the rise of temperature of motor is the highest, and the rise of temperature of the back-end of spindle is the lowest. Thermal displacement on the front of spindle is the largest, and it is the main part that affects the precision of machining center.
Size-Controlled Synthesis of Magnetite Nanoparticles from Iron Acetate by Thermal Decomposition
Authors: Shao Hui Ping , Tan Yi Ming , Lin Tao , Guo Zhi Meng
Published: November 2012

Magnetite nanoparticles with an average particle size ranging from 4.2 to 34.2 nm were synthesized by thermal decomposition of iron(II) acetate with and without a reducing agent. While in the presence of reducing agent, magnetite nanopartices with an average size of 4.2 nm and 12.6 nm were synthesized by varying the amounts of the surfactants. While in the absence of the reducing agent, magnetite nanoparticles with an average size of 26.4 nm and 34.2 nm were prepared.
Method of Identifying Key Quality Characteristics in Multistage Manufacturing Process Based on PLSR
Authors: Wang Ning , Xu Ji Chao , Yang Jian Feng
Published: November 2012

To improve the existing methods of identifying the key quality characteristics in multistage manufacturing process, the partial least squares regression (PLSR) method is combined with the state space model that a new method of identifying the key quality characteristics in multistage manufacturing process based on PLSR is proposed. According to the feature of multistage manufacturing process, the state space model is introduced to build the key quality characteristics identifying model for multistage manufacturing process, using the PLSR method to solve the problem of the quality characteristics such as multicollinearity, do model analyzing and identify the key quality characteristics. At last, the cigarette production process is presented as an example to introduce the application of this method. The result shows that this method can not only identify the key quality characteristics in multistage manufacturing process, but also establish the model of output quality effecting of all levels on the final product quality and its quality characteristics relationship, which reflect the structure of the multistage manufacturing process and causal relationship between quality characteristics at all process levels, provide the basis for quality analysis and control in multistage manufacturing process.
A Directional Multivariate Control Chart for Monitoring Univariate Autocorrelated Processes
Authors: Yang Wen Wan , Zi Xue Min , Zou Chang Liang
Published: November 2012

A new nonparametric multivariate control chart, based on a spatial-sign test and integrating the directional information from processes with the exponentially weighted moving average (EWMA) scheme, is developed for monitoring the mean of a univariate autocorrelated process. Simulation studies show that it has robustness in in-control (IC) performance, and it is more sensitive to the small and moderate mean shifts for non-normality underlying process than other existing multivariate chart methods.
A New Circuit Detection Method and an Anomalous Frequency Recognition Algorithm
Authors: Xu Wen Dan , Tian Yuan , Jiang Jian Guo , Yu Ting , Liu Zhi Wei
Published: November 2012

The characteristics of the high-density circuits are high assembly density of the components and complex functions. It is difficult to detect the electrical defects by the existing optical techniques. The Electromagnetic Scan (EMScan) technology as a new detection method was introduced into the high-density circuit detection. For the new approach, the EMScan process was designed and its key techniques were analyzed. Meanwhile the corresponding recognition algorithm was given toward one of the key techniques determining the anomalous frequencies. The spectrums of the circuit board were transformed into a series of strings. Then according to the string comparison algorithm, the anomalous frequencies were determined. The experimental results show that it is feasible to apply the EMScan into the high-density circuit detection. The recognition algorithm is effective and can determine the anomalous frequencies accurately by this way.
The Application of Abaqus Software in the Online-Quenching Process of 6005 Aluminum Alloy Profile
Authors: Huang Zhi Qi , Wang Gang , Yin Zhi Min
Published: November 2012

The online-quenching process of 6005 aluminum alloy was simulated by using Abaqus software, the stress field of alloy profile in different quenching temperatures and quenching processing were obtained. The results indicate that during quenching the temperature of the profile is decreasing and the internal stress gradually increasing. At the same time the stresses of different parts of the profile are different, the maximum stress is at the corner, the second in the center and the rest lower. Under the premise of keeping the performance of the alloy, the internal stress after step quenching is significantly lower than that after one-time quenching.
Study on Structure Stability of Ti-Al Multilaminate Material at High Temperature
Authors: Feng Gang , Zhang Chao Ge , Zhao Xian Rui , Ma Li
Published: November 2012

Ti-Al multilaminate composite was prepared by high-power EB-PVD technology, and under vacuum condition, the samples were annealed at different temperatures. The changed microstructure of the samples after annealing was characterized by XRD, SEM and EDS. The experimental results show that, with the increment of temperature, the ordered phases reduce due to the diffusion of Al into Ti, and the breakdown of layered architecture was induced mainly by pore formation, grain growth and the grain boundary grooving.
Properties of Low-Carbon Al2O3-C Refractories with Different Critical Particle Size
Authors: Niu Chong Chong , Liu Guo Qi , Wu Xiao Xian , Yu Jian Bin , Qin Hong Bin
Published: November 2012

Low-carbon Al2O3-C refractories were prepared using white fused corundum, α-Al2O3 powders and flake graphite as main raw materials. The critical particle sizes of corundum selected in this experiment were 0.5mm, 1mm and 2mm. The effects of corundum critical particle size on physical, mechanical and thermo-mechanical properties of low-carbon Al2O3-C refractories were investigated. The results show that the increase of critical particle size is conducive to the improvement of thermal shock resistance and fracture energy, but little effect on thermal expansion. The cold modulus of rupture after thermal shock test of samples using 0.5mm critical particle size corundum was 2.09MPa, while using 2mm critical particle size corundum was 2.98MPa. And the fracture energy increased from 265N/mm to 588N/mm when the critical particle size increased from 0.5mm to 2mm. The effects of critical particle size on apparent porosity, bulk density and modulus of rupture were insignificant.
Research on the Tribology Performance of Copper-Bismuth Bearing Material
Authors: Yin Yan Guo , Jiao Xiang Nan , You Tao , Yu Jian Wei , Jiao Ming Hua , Xie Ting
Published: November 2012

Copper-based bearing material containing Bi was prepared by running powder metallurgy process, the influence of the content of Bi on the tribological performance of copper-based bearing materials was inspected and Bi’s impact on frictional wear performance of copper-based bearing materials was studied by a MM-200 frictional wear tester. The research shows that, Bi, with a lower melting point, tends to melt and separate out, in friction process which may reduce shear strength of the friction pair surface and improve the performance of antifriction and adhesiveness resistance. When Bi content gets higher to produce more brittle phases, which will fall off directly from the matrix, the antifriction and antiwear of friction pair will weaken.
Effect of Initial Texture on the Development of Microstructure and Mechanical Properties in AZ31 Magnesium Alloy after Rolling at 300°C
Authors: Park No Jin , Ha Chang Wan
Published: November 2012

Mg alloys are drawing a lot of attention and have been extensively studied. The major obstacle to the practical application of the alloys is the poor formability at room temperature, originating basically from the insufficient number of slip system. Development of a proper microstructure and/or texture is one promising solution to improve the formability. In the present work, after extrusion and full annealing, rolling at 300°C with different starting textures, the microstructures, texture developments and tensile properties of AZ31 Mg alloys are studied. After full annealing strong ∥ED fiber texture and weak + ∥ED fiber texture (c-axes in the radial direction) were developed. After rolling at 300°C many twins were formed, and the strong ∥ED fiber texture changed to ∥ND texture. Yield strength, tensile strength and elongation changed obviously depending on the microstructure and textures.
Workability of ZK60A Alloy Depending on Microstructure
Authors: Jung K.H. , Kim Yong Bae , Ahn Byung Min , Lee Sang Mok , Lee Jong Sup , Choi Du Soon , Lee Geun An
Published: November 2012

In this study, the variation of workability of semi-continuously casted and extruded ZK60A magnesium alloy was investigated. To determine the deformation capability of two different billets, uniaxial compression tests were conducted at elevated temperatures and two different strain rates. In addition, the microstructural evolution was investigated using electron backscatter diffraction (EBSD) to compare the microstructure before and after the extrusion. The formability of ZK60A depending on the microstructure is discussed based on the experimental results obtained in this study, and is compared with earlier research in the literature.
Effects of Cu and Sb on Corrosion Resistance of ZnAl27 Alloy
Authors: Hao Cheng Gang , Zeng Jian Min , Chen Jun , Chen Ping , Xiao Jian Qiang
Published: November 2012

The corrosion behavior of ZnAl27 alloys in 35g/L NaCl solution has been studied by electrochemical and immersion corrosion tests. The effects of Cu and Sb on the Tafel curves, electrochemical parameters of free corrosion potential, linear polarisation resistance (LPR) and free corrosion current, of the ZnAl27 alloy have been investigated. The surface morphologies of the alloy after immersion corrosion tests have been observed through SEM. The results indicate that addition of proper Cu can improve its corrosion resistance of the alloy, or the free corrosion potential the corrosion current shift towards the positive and negative,respectively. However, excessive addition of Cu can deteriorate the corrosion resistance of the alloy. On the other hand, the corrosion resistance of the ZnAl27 alloy decreases with the increasing of Sb content.
Study on Sintering Properties and Crystallization of Fused Quartz Ceramic Materials Containing BN-B4C
Authors: Shen Shu Bin , Bu Jing Long , Yu Li Xue , Chen Jun Xing , Wang Zhi Fa
Published: November 2012

Different dosages of BN-B4C compound additive have been introduced for preparing specimen with fused quartz granule (d50=10μm). Fused quartz ceramic materials were fabricated in reduction atmosphere at various temperatures for 1h. The characterizations were carried out by thermal expansion ratio, apparent porosity, cold modulus of rupture (CMOR) and SEM as well as by X-ray diffraction (XRD). The effect of BN-B4C on the sintering, crystallization and properties of fused quartz was investigated. The result reveals that with increase of the temperature, the apparent porosity and CMOR of specimens decrease. The specimen C sintered at 1300°C possessed a maximum CMOR (22.31 MPa). The specimen C sintered at 1350°C has more compact microstructure. The lowest thermal expansion ratio of the specimens sintered at various temperatures was obtained when the dosages of compound additive is 3%. With increasing BN-B4C content, the role on inhibiting crystallization was improved. The specimens containing 3 wt% BN-B4C had obvious effect on inhibiting crystallization of the specimens sintered at various temperatures.
Effect of Phosphorus on the Mechanical Properties and Microstructure of Interstitial Free Steel
Authors: Wang Zhi Fen , Han Rong Dong , Zhou Shun Bin , Huang Hai E , Wu Li Xin
Published: November 2012

Effect of phosphorus content on the mechanical properties and microstructure of IF steel sheets was investigated. Average grain size and recrystallization texture were measured by electron backscatter diffraction (EBSD). The results showed that the higher P resulted in higher tensile strength and lowered the elongation and r-value. The average grain size increased with decreasing P content. The //ND (γ-fiber) pole intensity had a lowest value for IF steel with the highest P content which in turn deteriorate r-value. The element P played an important role in recrystallization process which affected the mechanical properties and microstructure of IF steels.
Study on the Key Technologies of Direct Reduction for Rotary Hearth Furnace Dealing with Carbon Containing Pellets
Authors: Qin Jie
Published: November 2012

The current development of derect reduction technology for rotary hearth furnace (RHF) is introduced. It is essential to stable and continuous operation of the RHF carrying out the following technologies: the cold-pressing technology，design of the charging machine and discharging machine of the RHF, temperature, pressure and atmosphere in the furnace, and the antioxidation of the metallized pellets. The current develop situation of these technologies are fully discussed.
Study on Desulphurization Technology in RH Refining for Electric Steel
Authors: Zhang Min , Zeng Jian Hua , Pan Hong
Published: November 2012

To develop the desulphurization technology for electric steel, desulfurizer using for electric steel in RH refining process has been studied. Meanwhile, key technologies such as converter end-point control, modification of ladle slag in secondary refining process, as well as desulphurization technology in RH refining process are studied deeply. Industrial tests show that desulphurization rate in RH refining process is as high as 28% for electric steel, and the ratio which sulfur content below 0.005% is as high as 70%.
Effect of the Strain Rate on Mechanical Properties and Microstructure of High Strength Low Alloy Steel HC340LA
Authors: Liu Xiao Hang , Yuan Wen Jing , Tian Hao Bin , Diao Fa Xi
Published: November 2012

The mechanical properties and microstructure of the high strength low alloy HC340LA were obtained with different strain rate. The research shows that the better plasticity, higher tensile strength and yield ratio can be found in high speed tensile state than in quasi-static tension. The plasticity and tensile strength decrease with the increasing of the strain rate during the high speed tension. With the increasing of the strain rate, the grain size of the ferrite decreases and its distribution is uneven, and the grain boundaries increases. The HSLA steel HC340LA submit to obvious Ductile Frecture mechanism. The size of the dimples is more uniform, bigger and deeper with the strain rate 50 s-1 than with the strain rate 200 s-1. Therefore, the higher strain rate with over strain rate 50 s-1 has less Superscript textcontribution to the improvement of plasticity of the HSLA steel HC340LA.
Calculation of Carbon Diffusion Coefficient in Spheroidal Graphite Cast Iron
Authors: Li Tong Tong , Pan Xiang Ning , Zheng Hong Liang , Tian Xue Lei
Published: November 2012

Two S-type thermocouples connected to paperless recorder are used to record the temperature change during solidification of the wedge spheroidal-graphite casing. The cool-down time and eutectic temperature are obtained from the cooling curves which are calculated by Pro CAST software. Aided by the image-pro plus software, graphite nodules’ mean diameter and amount can be obtained. Carbon diffusion coefficient of graphite nodule is calculated according to the spherulite growth model. The result is in good agreement with the reference date which shows the validity of parameters. It could provide the parameters for simulation of casting solidification.