bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Plate Bending in Coilbox by Finite Element Method
Authors: Yu Xiang Long , Yang Quan , Jiang Zheng Yi
Published: June 2010

Using finite element method (FEM), the results of bending conditions of the intermediate plate at the bending rolls of a coilbox between the roughing and finishing stands in a hot strip mill were obtained. The intermediate plate was coiled in a coilbox, which effectively overcame the problem of temperature drop by reducing surface area exposed to radiant heat loss during the waiting period. Different states of the plate in the coilbox were simulated by FEM, and the mathematical model of the bending rolls was established, which was in accord with the simulation results that the plate was coiled. As the bending shape of the front end of the intermediate plate is crucial to coiling process, the curvatures of the plate were predicted through FEM. In addition, the roll diameter and arrangement affect the optimum curvature, thus the parameters for bending rolls were determined without many adjustments. The developed bending model has been applied to actual coilbox in plant.
Fabrication of Ultrafine Grained Copper Alloy by 3-Layers Accumulative Roll-Bonding Process
Authors: Lim Cha Yong , Kim Hyoung Wook , Lee Seong Hee
Published: June 2010

The 3-layers accumulative roll bonding process (ARB) has been attempted to increase the strength of copper alloy (Cu-0.02wt.%P) by refining grain size. The 3-layers accumulative roll bonding was conducted up to 7 cycles at room temperature without lubrication. Microstructural evolution of the copper alloy with the number of the 3-layers ARB cycles was investigated by optical microscopy (OM), transmission electron microscopy (TEM), and electron back scatter diffraction (EBSD). The average grain size has been refined from 20 μm before ARB to 170 nm after 7 cycles of 3-layers ARB. More than 70% of ultrafine grains formed by 3-layers ARB were composed of high angle grain boundaries. The average misorientation angle of ultrafine grains was 30.7 degrees in the center of the specimen. Tensile strength after 7 cycles of 3-layers ARB was 605 MPa, which is about 3.2 times higher than the initial value.
The Effect of Heat Treatment on Formability of Ultra-Fine Grained AA6061 for Bolt Manufacturing
Authors: Choi Jun Seok , Jin Young Gwan , Im Yong Taek
Published: June 2010

Equal channel angular extrusion (ECAE) was used before and after artificial aging to investigate the effect of heat treatment on formability of bulk nanostructure of commercially available aluminum alloy of AA6061 in the present study. In the ECAE, route A was applied up to four or eight passes by using the split dies set-up. The three-stage bolt forming using the ultra-fine grained specimens was carried out to check formability of the material. In the present experiments, the bolt forming was successful with the specimen prepared by the ECAE after artificial aging whilst it was not successful with the specimen prepared by a reverse process sequence. The strength increase was confirmed by the tension and microhardness tests and compared to the result of conventional AA2024 bolt made by the conventionally heat treated specimen. It was found that the strength was comparable to the level of the heat treated conventional one although the actual value was a little bit lower. In addition, it was demonstrated that the heat treatment sequence is important to achieve proper formability of the ultra-fine grained material to manufacture the high strength bolt.
Design Technique Research of Fine-Forged Spur Bevel Gear Tooth Profile Modification
Authors: Cui Huan Yong , Tian Xi Jie , Wang Dong Liang
Published: June 2010

Gear tooth profile modification can be featured to improve working stability of gear equipments, abate noise and vibration, enhance loading ability and prolong usage life of the gears. Fine forged spur bevel gear are formed with molds, so it is economical to modify the gears by means of modifying mold cavity. Whether the modified gears can be separated from the mold with easiness is proposed to be the basic criterion of gear tooth profile modification design. Near the big ends and tooth roots is mainly the area which affects demolding after modification. According to the modified gear configuration, mathematical model is built to calculate the demolding check at any modification points on the fine forged spur bevel gear profile. And a corresponding program is developed, which is the main tool for the gear tooth profile modification design, and practical calculation has carried out.
Design and Simulation Based on Virtual Prototype of New Apparatus for High Velocity Compaction
Authors: Guan Hang Jian , Shao Ming , Xiao Zhi Yu
Published: June 2010

High velocity compaction (HVC) is one of the latest technologies of powder metallurgy (PM), while the prices threshold of Hydropulsor’s HVC presser limited massive application of this technique in vast minor PM enterprises in Mainland China. In the light of this, the paper delivers a new design of HVC apparatus which adopts mechanical springs groups instead of hydraulic cylinder as hammer driver. The virtual prototype and simulation of new HVC apparatus is brought about. The result of simulation shows that new design can basically meet the demand of HVC.
Effects of Surface Strength and Temperature on Warm Forming of MG-AL-SUS Clad Sheet
Authors: Lee Young Seon , Jung Taek Woo , Kim Dae Yong , Moon Young Hoon
Published: June 2010

Clad metal sheets are composed of one or more different materials joined by resistance seam welding, roll-bonding process, etc. Good formability is an essential property in order to deform a clad metal sheet to a part or component. Temperature is one of the major factors affected the interface strength and formability on warm forming of multilayered sheet metal. In this study, the mechanical properties and formability of a Mg-Al-SUS clad sheet are investigated. The clad sheet was deformed at elevated temperatures because of its poor formability at room temperature. Tensile tests were performed at various temperatures above 250°C and at various strain rates. The limit drawing ratio (LDR) was obtained using a deep drawing test to measure the formability of the clad sheet. Interface strength and fracture pattern were changed mainly by temperature. Uniaxial tensile strength represents entirely different type below and above 200°C at also different strain rate. Mg alloy sheet was fractured earlier more than SUS and Al alloy sheet below 250°C testing temperature. On the contrary, Mg alloy sheet was elongated much more than other metals above 250°C.
Influence of Annealing Treatment on Formability and Springback for Magnesium Alloy Sheets
Authors: Kim Dae Yong , Hwang Bum Kyu , Lee Young Seon , Kim Sang Woo , Moon Young Hoon
Published: June 2010

The purpose of this work is to experimentally investigate the effect of annealing treatment on the formability and springback at room temperature for magnesium alloy AZ31 sheets, which were produced by rolling through reversible warm mill after twin roll strip casting. Microstructure evolutions were investigated using OM after annealing at temperature raging from 350°C to 450°C. Tensile tests at room temperature were performed to show the influence of annealing treatment on mechanical properties. In order to evaluate the formability in stamping processes, the Erichsen cupping tests were carried out and the Erichsen number were measured. As for springback, the V shaped air bending tests were achieved and the angle changes after springback were collected. The experimental results showed that Erichsen numbers increased by the annealing treatment, while springback angle decreased.
Prediction of Load Capacity Behavior of Multi-Stage Formed Construction Elements
Authors: Petek Aleš , Kuzman Karl , Resman Franc , Jerman Boris , Zaletelj Viktor
Published: June 2010

The technologies for low-quantity production of sheet metal components and parts are applied mostly for thin single metal sheets. However, such technologies could also be applied as an additional procedure in multi-layer construction element production. Such individually produced construction elements must correspond to required standards, which are usually applied in serial production. Due to the immense testing work expected by custom-made production, it is reasonable to develop a methodology that would be capable of predicting the required results of an individually designed and produced construction block quickly, effectively and with minimal costs. In this investigation, a method of predicting the load capacity behavior of individual construction elements performed by incremental forming as an additional technology in multi-layer construction element production is presented. Special attention is dedicated to the definition of finite element model of a standardized four-point bending test and its correlation to real experimental results.
Reciprocating Shaving Approach to Eliminate Crack and Burr Formations in Pressed Parts
Authors: Thipprakmas Sutasn , Phanitwong Wiriyakorn , Chinwithee Mutjarin , Morkprom Thanaporn
Published: June 2010

Burrs are unwanted materials remaining not only after the machining operation but also after the sheet metal cutting operation. Burr formations decrease the part accuracy and increase the cost for the deburring operation. In this study, the reciprocating shaving process was proposed to eliminate crack and burr formations in the pressed parts. The finite element method (FEM) was used as a tool to investigate the possibility of this process and its working process parameters as well. The FEM simulation results showed the effects of clearance in shearing operation, shaving allowance, and half-shaving direction on the shaved surface. These results were validated by laboratory experiments, and they showed a good agreement with each other. The FEM simulation could be used as a tool for prediction of the cut surface in the reciprocating shaving process. The results revealed that the reciprocating shaving process could be applied for eliminating crack and burr formations in pressed parts using suitable working process parameters.
Collaborative Aluminum Profile Design to Adaptable Die Process Planning Using Neural Networks
Authors: Butdee Suthep , Noomtong Chaiwat , Tichkiewitch Serge
Published: June 2010

Aluminum extrusion die manufacturing is a critical task for productive improvement and increasing potential of competition in aluminum extrusion industry. It causes to meet the efficiency not only consistent quality but also time and production cost reduction. Die manufacturing consists first of die design and process planning in order to make a die for extruding the customer’s requirement products. The efficiency of die design and process planning are based on the knowledge and experience of die design and die manufacturer experts. This knowledge has been formulated into a computer system called the knowledge-based system. It can be reused to support a new die design and process planning. Such knowledge can be extracted directly from die geometry which is composed of die features. These features are stored in die feature library to be prepared for producing a new die manufacturing. Die geometry is defined according to the characteristics of the profile, is called product data, so we can reuse die features from the previous similar profile design cases. This paper presents the artificial neural network to assist aluminum extrusion die design and process planning based on collaborative design methodology. Product data can be shared and distributed in die design team members via computer network technology. This product data is used to support die design and process planning. Die manufacturing cases in the case library would be retrieved with searching and learning method by neural network for reusing or revising it to build a die design and process planning when a new case is similar with the previous die manufacturing cases. The results of the system are dies design and machining process.
Fabrication of a Large-Area Silicon Mold with Microstructures Using a Novel Recombining Technique
Authors: Wu Chih Wei , Chi Chih Heng , Tsai Hung Yin , Shen Yung Kang
Published: June 2010

This paper presents an innovative fabrication of a large-area silicon mold with microstructures. Conventional techniques capable of manufacturing a large size mold pose severe challenges in making microstructures. In contrast, semiconductor process is limited in its wafer scale. This paper shows a new approach to achieve a large beyond-wafer-size silicon mold with alignment microstructures using two-direction passive alignment recombining techniques. Anisotropic bulk-micromachining technique, laterally joined of (111) silicon crystal planes, passive-alignment methods are the key to fabricate a large-area silicon mold. The area of each small silicon plate is 2.9cm2. Therefore, four small silicon plates with microstructures were recombined as a large-area square silicon mold. The optical fibers were placed into V-grooves on small silicon plates to make sure of microstructures alignment, minimum tilting and rotation angles between plates during the recombining process. The gap, height difference, and aligning accuracy of microstructures between joined silicon plates were able to achieve 8μm, 0.902μm and 20μm, respectively. Moreover, the rotation and tilting angles could be lowered to 0.0622 degree and 0.002 degree, respectively. Microstructures on the large-area silicon mold are faithfully reproduced by polydimethylsiloxane (PDMS). Finally, a 16.8 cm x 12.6 cm silicon mold was fabricated using twelve 4.2cm x 4.2cm silicon plates. It is believed that the novel technique will give an impact and create a highly value-added technology to the precise mold manufacturing.
Die Design in Fine-Piercing Process by Chamfering Cutting Edge
Authors: Yiemchaiyaphum Suthep , Jin Masahiko , Thipprakmas Sutasn
Published: June 2010

The hole quality on sheet metal parts is directly dependent on the die design and process parameters. In conventional piercing process, the secondary operations such as shaving, reaming and grinding are needed for manufacturing the precise-dimensioned holed parts without any cracks, resulting in the increase of both production time and costs. The fine-piercing process, referenced to the fine-blanking principle, is used to produce the precise-dimensioned holed parts with smooth-cut surfaces over the whole material thickness in a single operation. However, it is difficult to achieve the suitable die design and process parameters for meeting the part requirements. In this study, the die design by chamfering punch cutting edge was investigated on both the experiments and the finite-element method (FEM). The results were compared with the results obtained when the conventional die design with the punch cutting-edge radius was used. The FEM-simulation results showed the amount of die-roll, smooth-cut surface, and cracks agreed well with the experimental results. The results showed that an application of punch cutting-edge chamfer results in a superior fine-pierced hole surface could be achieved. Furthermore, the mechanism and effects of the punch cutting-edge chamfer have been theoretically clarified on basis of the material-flow analysis and stress distribution.
Optimisation of the Machining of Stellite 6 PTA Hardfacing Using Surface Roughness
Authors: Hasan Md Shahanur , Abdul Md Mazid , Clegg Richard E.
Published: June 2010

Stellites are cobalt based super alloys. By virtue of their excellent physio-mechanical properties, stellites are highly regarded engineering materials. Stellites posses high corrosion resistance and wear resistance properties. This study investigates the Stellite deposition process and machinability of Stellite 6 deposited on steel subtrate. Stellite 6 was deposited onto a 4140 bar using a plasma transfer arc (PTA) system and machinability was assessed on the basis of surface roughness. A series of turning operations have been carried out on a conventional lathe using coated carbide inserts and surface roughness was evaluated by Stylus type Surtronic3+ instrument. The values of surface roughness were plotted against different cutting speed, feed rate and depth of cut to display the results in graphical forms. Optimal cutting regimes were established against the best values of surface roughness.
Surfaces Machined by Micro End-Mills at Constant Chip Load
Authors: Liow Jong Leng , Frye Ulrich
Published: June 2010

The surfaces of Al6061, machined by 150 μm two flute micro end-mills, were studied to determine their roughness. The surface roughness, Ra, was less than 100 nm but the Ra/Rz ratio ranged from 0.03–0.12. The surface roughness was found to improve with increasing width of cut and to a lesser extent with increasing feed rate. A single pass of the end-mill was found to produce a smoother surface than two passes over the same surface. The surface roughness was found to correspond to the diameter of the end mill and the slope of the secondary cutting edge. To reduce the surface roughness, smaller diameter end mills and chip loads should be used.
Design Optimization of Cutting Parameters in Turning 45Cr Steel Using Cermets Tool
Authors: Han Zhi Lin , Lin Bin , Zhang Bao Xing , Zhang Lei
Published: June 2010

In this paper, the optimization of cutting parameters in turning thin-walled 45Cr steel workpieces with cermets tool is researched. A new integrated optimization method is proposed, in which the parameter design of the Taguchi method, principal component analysis method and response surface method (RSM) are applied to obtain the optimal parameter for a hard turning process using mixed cermets tools. The orthogonal array experiment is conducted to economically obtain the response measurements. The Principal Component Analysis (PCA) is applied to transform the original evaluation variables into new, uncorrelated comprehensive variables, which includes most information of original variables, then the output response can be calculated by the principal components. At last, the RSM is used to build the relationship between the input parameters and output responses, and obtain the desired machining parameters. The quality of workpieces and the process efficiency are improved obviously.
Cutting Performance and Wear Mechanisms of an Al2O3-Based Micro-Nano-Composite Ceramic Tool
Authors: Zhou Yong Hui , Zhao Jun , Ai Xing
Published: June 2010

An Al2O3-based composite ceramic cutting tool material reinforced with (W, Ti)C micro-particles and Al2O3 micro-nano-particles was fabricated by using hot-pressing technique, the composite was denoted as AWT. The cutting performance, failure modes and mechanisms of the AWT micro-nano-composite ceramic tool were investigated via continuous turning of hardened AISI 1045 steel in comparison with those of an Al2O3/(W, Ti)C micro-composite ceramic tool SG-4 and a cemented carbide tool YS8. Worn and fractured surfaces of the cutting tools were characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results of continuous turning revealed that tool lifetime of the AWT ceramic tool was higher than that of the SG-4 and YS8 tools at all the tested cutting speeds. The longer tool life of the AWT composite ceramic tool was attributed to its synergistic strengthening/toughening mechanisms induced by the (W, Ti)C micro-particles and Al2O3 nano-particles.
Theoretical Research of the Axial Force about Cross Wedge Rolling
Authors: Peng Wen Fei , Zhang Kang Sheng
Published: June 2010

Axial force in CWR is an important force and energy parameter for stable rolling, which plays an important role in studying the forming quality of asymmetric shaft-parts, section shrinkage of rolled parts and rolling of heavy area reduction. By simplifying boundary conditions of solving axial projected area in this paper, and considering the effects of frictional force generated by contact surfaces between the tools and shaped shaft-section, the formula of the axial force has been derived by analytical method; by comparison of axial force values simulated by ANSYS/LS-DYNA FE software and measured through experiment, the formula of the axial force is verified correctly. The analyzing results provide useful reference for solving process problems caused by axial force.
Fast Tool Servo Machining of Complex Surfaces and Microstructures
Authors: Wang Gui Lin , Zheng Zi Wen , Yang Hai Kuan , Dai Yi Fan
Published: June 2010

Optical components with complex surfaces or microstructures are more and more widely used, but it is very difficult to manufacture these components by using traditional mechanical fabrication methods. Fast Tool Servo (FTS) system driven by piezoelectric ceramic (PZT) can manufacture these complex surfaces or microstructures efficiently and accurately, owing to its high response frequency, good dynamic performances and high stiffness. In this paper, the cutting characteristics are studied in the FTS machining process, and the identifying algorithm of tool interference is given. A set of high-powered FTS system is developed, which consists of PZT, fast feeding device, DSP28335 control panel and ultraprecision machine tool. The testing results indicate that the FTS system’s motion resolution is 1nm, the stroke is 90μm, and the response frequency is 220Hz while moving distance is 36μm. On the basis of above work, three kinds of typical workpieces with complex surfaces are manufactured by using FTS system. The measuring results indicate that surface accuracy can reach PV 0.14μm, the roughness is less than Ra 12nm, and the means are presented to improve the machining accuracy.
Structure Optimization of Variable Pitch Helix End Mills Based on FEM Simulation
Authors: Huang Pan Ling , Li Jian Feng , Sun Jie
Published: June 2010

Chatter is one of the main factors that affects the manufacturing quality and limits the productivity during milling. If properly selecting mills with variable pitch distribution, the chatter may be reduced. If mills have sufficient rigidity, its vibration resistance will be improved extremely. The paper summarizes the effects of helix angles, pitch angles distribution on the maximum stress, the maximum strain based on FEM simulation, the result of simulation can offer theoretical instructions to optimize and select the optimal mills based on intensity and rigidity.
Identification of Stability Lobes in High-Speed Milling Flexible Parts with Bull-Nose End Mills
Authors: Wan Yi , Song Qing Hua , Liu Zhan Qiang
Published: June 2010

Flexible parts such as turbine blade, blisk and monolithic components are widely used in the aeronautical industry, and high Speed Machining (HSM) technology is used to increase productivity and reduce production costs. Chatter is an undesirable phenomenon in high speed machining processes because of deteriorative surface finish, early cutting tool failure and unexpected machine tool damage. It can be avoided in higher speed milling processes if stability lobes is determined. In this paper, a non-linear regenerative force model is applied to a bull-nose tool geometry in order to obtain the machine operation stability lobes. An analytical-experimental method is proposed to obtain the stability lobes during high speed milling flexible parts with bull-nose end mills. The method is calculated and validated.
A Knowledge Based Hybrid Model for Improving Manufacturing System in Rolling Mills
Authors: Abhary Kazem , Garner Keith , Kovacic Zlatko , Spuzic Sead , Uzunovic Faik , Xing Ke
Published: June 2010

Hot steel rolling is amongst the most important industrial techniques because of huge amount of consumed resources, immense environmental impact, and the significance and enormous quantity of long products. Criteria for improving rolling operations include process efficiency, resource consumption, system reliability, product quality and ergo-ecological sustainability. There is an increasing availability of information within and beyond the domain of forming by rolling. With advances in computerised information processing, it becomes apparent that further progress is to be sought in intelligently combining the strategies and theories developed in differing disciplines. The key to optimising rolling systems is to be found in hybrid models. This approach calls for utilising cross-disciplinary knowledge, including a selection amongst methods such as stochastic, fuzzy and genetic modelling, process control and optimisation as well as supply chain and maintenance management. Evidence obtained by experiments using small-scale chemo-physical modelling encourages the use laboratory rolling for preliminary validations. Research strategy is conceptualised on the basis of a knowledge-based hybrid model. The sample space for this model is constituted by the rolling passes translated into the form of vectors. An example of a rolling pass translation into the vector form is presented.
Simulation of Three-Dimensional Dynamic Cutting Forces and Chatter Stability in Ball-End Milling
Authors: Zhao Jun , Zhang Xiao Feng , Luo Han Bing
Published: June 2010

By taking into account the regenerative chatter vibration, a nonlinear dynamics model for high speed ball-end milling is proposed. The effect of dynamic components of milling forces on chatter is analyzed. A method to predict the stability limits of high speed ball-end milling process is proposed and the stability lobes diagram is simulated. The comparison of experimental milling forces with the simulation results indicates the high accuracy of the model and the effectiveness of the simulation algorithms. The proposed method provides a theoretical instruction for parameters selection and optimization in milling processing.
Research and Development of Four Axis Linkage Grinding Simulation System of Ball-Nose End Mill
Authors: He Lin , Zhao Xian Feng , Shi Hong Yan , Wang Jun
Published: June 2010

The four axis linkage grinding simulation system of ball-nose end mill has be developed based on the mathematical model of four axis linkage grinding through establishing ball-nose end mill's parametrical database, constructing ball-nose end mill’s and grinding wheel's solid models in Solidworks, simulating the grinding processes of the rake face and flank face of ball-nose end mill based on Boolean operation, and automatic NC programming of rake face and flank face grinding. The results show the grinding simulation system can be used to manufacture ball end mill.
Cutting Performance and Wear Mechanism of Si3N4-Based Nanocomposite Ceramic Tool
Authors: Zou Bin , Huang Chuan Zhen , Liu Han Lian , Song Jin Peng
Published: June 2010

Si3N4/TiN nanocomposite tool and Si3N4/Ti(C7N3) nanocomposite tool were prepared. The cutting performance and wear mechanism of Si3N4-based nanocomposite ceramic tool was investigated by comparison with a commercial sialon ceramic tool in machining of 45 steel. Si3N4-based nanocomposite ceramic tool exhibits the better wear resistance than sialon at the relatively high cutting speed. The increased cutting performance of Si3N4-based nanocomposite ceramic tool is ascribed to the higher mechanical properties. Nano-particles can refine the matrix grains and improve the bonding strength among the matrix grains of Si3N4-based nanocomposite ceramic tool materials. It contributes to an improved wear resistance of the cutting tools during machining.
Research on Five-Axis Dual-NURBS Adaptive Interpolation Algorithm for Flank Milling
Authors: Wang Yu Han , Feng Jing Chun , Chao Sun , Chen Ming
Published: June 2010

In order to exploit the advantages of five-axis flank milling method for space free surface machining to the full, a definition of non-equidistant dual-NURBS tool path is presented first. On this basis, the constraint of velocity of points on the tool axis and the constraint of scanning area of the tool axis are deduced. Considering both of these constraints, an adaptive feed five-axis dual-NURBS interpolation algorithm is proposed. The simulation results show that the feedrate with the proposed algorithm satisfies both of the constraints and the machining time is reduced by 38.3% in comparison with the constant feed interpolator algorithm.
Factors in Practical Manufacturability Analysis of Layer-Based Machining (LBM)
Authors: Chen Yong Hua , Yang Zheng Yi , Ye Rui Hua
Published: June 2010

In layer based machining (LBM), a part is sliced into thick layers, and each layer is shaped by 5-axis robot machining. Therefore, this technique is expected to have the merits of both layered manufacturing and CNC machining. As a new process, manufacturability analysis of LBM is carried out to determine whether a given part is suitable for LBM or not. This analysis is further studied based on supportability analysis and machinability analysis. Results of the manufacturability analysis are used for LBM process parameter selection and build orientation determination.
Experimental Studies on the Influence of Cutting Parameters on Thrust Force and Torque during Drilling of GFRP with SiC Fillers
Authors: Senthil Kumar Mouleeswaran , Krishnaraj Vijayan
Published: June 2010

The paper discusses the influence of cutting parameters such as cutting speed, feed rate and point angle on thrust force and torque while drilling of Glass Fiber Reinforced Plastic (GFRP) composites with Silican Carbide (SiC) fillers. The experiments were conducted during the drilling of GFRP with SiC fillers using four standard twist drills of point angles 90º, 100º, 110º and 120º. Conclusions thus drawn are presented and can be useful for the selection of the best cutting parameters.
Investigations on Drilling of Multimaterial and Analysis by ANN
Authors: Krishnaraj Vijayan , Zitoune Redouane , Collombet Francis
Published: June 2010

This paper presents experimental and analytical investigation on drilling of carbon fibre reinforced plastic and aluminium stacks. The experimental results conducted as per full factorial experimental design reveal that drill diameter and feed rate have significant effects in reducing thrust force and torque while spindle speed has the least effect. The analytical study is based on artificial neural network (ANN) training using feed-forward back propagation network. The correlations obtained by multi-variable regression analysis and ANN, indicate that ANN is more effective than regression analysis.
Understanding the Temperature Field in Plunge Cylindrical Grinding for Grinding-Hardening
Authors: Nguyen Thai , Zhang Liang Chi
Published: June 2010

This paper investigates the temperature field in plunge cylindrical grinding with the aid of the finite element analysis. The analysis included the effect of the variation of the depth of cut and that of the repeated heating and cooling caused by workpiece rotation. It was found that the predictions agree well with the experimentally measured results. The analysis showed that the heating in the consequent rotations further raises the temperature in the workpiece. The reheating in the hardened layer can lead to material’s tempering.
A New Calculating Model of Rolling Pressure during Temper Rolling Process
Authors: Du Xiao Zhong , Jiang Zheng Yi , Bai Zhen Hua , Yu Xiang Long , Zhang Zhong Yuan
Published: June 2010

A set of new mathematical models have been developed to calculate the temper rolling force of 2050 strip temper rolling mill. Based on the fact of small plastic deformation and elastic deformation occurring on the entry and exit of the deformation zone, new stress boundary conditions are described. The inhomogeneous distribution of internal stress in thickness direction is taken into account in the models, instead of uniform internal stress and assumption of plane strain traditionally. The new mathematical models have been applied into the temper rolling of 2050 hot rolling mills with good results. Comparison of calculated values and testing values for nine typical products has been given. The result shows that the calculated value of rolling force of temper mill is accurate.
Study on Grind-Hardening Temperature Field Based on Infrared Temperature Measurement and Numerical Simulation
Authors: Zhang Zhen Guo , Ge Pei Qi , Zhang Lei , Tian Mao Cheng
Published: June 2010

Based on the method of the statistical probability, the theory forecasting model of grinding force is modified analytically. The calculated force is used as an input factor to calculate the heat flux. Then the transient grinding temperature field is simulated using the finite element analysis (FEA). An infrared imaging system for a full area temperature measurement is used to validate the numerical model. Additionally, the experimental results are synthesized with the simulation results to analyze the temperature field and the hardness penetration depth (HPD). The distribution of the temperature field and the stability of the grind-hardening process are discussed, which could provide a reliable forecasting method for optimizing the grind process and controlling the hardening effects forwardly.
Phase Transformation and Stress Distribution in Polished PCD Composites
Authors: Chen Yi Qing , Zhang Liang Chi
Published: June 2010

With the aid of the Raman spectroscopy, this paper investigates the phase transformation and residual stress distribution in surfaces of polycrystalline diamond composites polished by dynamic friction technique. To clarify the contribution of phase transformations to residual stresses, the study focused on the surface which was incompletely polished such that the transformed phases remained. It was found that amorphous non-diamond carbon and amorphous graphite phase appeared in grain boundaries, but pristine diamond phase was predominant within gain areas. The residual stresses vary across the polished surfaces and the maximum stress locates at the grain boundaries.
Influence of Magnetic Field Strength on Polishing Effect of the Tiny-Grinding Wheel Cluster Based on the Magnetorheological Effect
Authors: Yan Jie Wen , Yan Qiu Sheng , Lu Jia Bin , Gao Wei Qiang
Published: June 2010

A new tiny-grinding wheel cluster polishing method based on the Magnetorheological (MR) effect is presented to polish optical glass in this paper and some process experiments were conducted to reveal the influence of magnetic field strength, the content of carbonyl iron in the MR fluid and the speed of polishing disc on the material removal rate and the surface roughness of the glass workpiece. The results indicate that when the external magnetic field is applied, the material removal rate of the workpiece improves rapidly but the surface roughness increases slightly. When the Magnetic field strength is 100 Gs and the content of carbonyl iron is 3.5%, the material removal rate improves by a factor of 16.8% compared with that of the conventional polishing methods with dissociative abrasive particles, while the surface roughness of the workpiece increases unobviously.
Molecular Dynamics Simulation of Rubbing Phenomena in Ultra-Precision Abrasive Machining
Authors: Shimizu Jun , Zhou Li Bo , Yamamoto Takeyuki , Huang Han
Published: June 2010

This study aims to clarify the friction and wear phenomena, which are of great importance in abrasive machining with atomic-scale material removal, such as polishing of magnetic disk substrates and CMP of semiconductor substrates. Various phenomena that occurred when a well-defined copper surface rubbed by an extremely fine rigid diamond abrasive, such asthe sliding without removal and the atomic-scale wear, were analyzed using a molecular dynamics model, in which the abrasive grain was connected to a three-dimensional spring and the holding rigidity of the abrasive grain was taken into account. A series of simulations using different indentation depths clarified that the one- or two-dimensional atomic-scale stick-slip phenomenon in proportion to the period of atomic arrays of workpiece surface occurred in the sliding processes without atomic removal. The results also demonstrated that the period and amplitude of the fundamental stick-slip wave varied when accompanied with atomic removal due to the increase in normal load.
Modeling of Depth of Cut in Abrasive Waterjet Cutting of Thick Kevlar-Epoxy Composites
Authors: Siddiqui Tauseef Uddin , Shukla Mukul
Published: June 2010

Abrasive water jet cutting (AWJC) is one of the widely used non-conventional techniques for cutting difficult-to-cut materials like composites, super alloys and ceramics. However, while conducting initial trials the inability of the jet to cut through the workpiece is a major problem particularly in thicker materials. Therefore an accurate prediction of depth of cut (DOC) is absolutely necessary to achieve through cuts and more so to minimize delamination in polymer matrix composites. In this paper, a semi-empirical model is developed using non-linear regression analysis for prediction of DOC in AWJC of thick Kevlar-epoxy composites. Further, the model is verified by conducting experiments within the investigated range of process parameters and a good agreement is obtained between the two.
Prediction of Erosion Profiles during ECM of Spiral Holes
Authors: Wang Ming Huan , Zhang Qiao Fang , Zhu C.K. , Yao C.Y. , Peng Wei
Published: June 2010

In this study the prediction of the erosion profiles during ECM of the spiral hole was presented. By assumptions, the major points were simplified into one-dimensional problems. The theoretical and computational model was built to illustrate the profile movement as the time elapses. The analysis was based on the law of electrolysis and the software MATLAB was used. Verifications were done through experiments and the deviation was 7.5% between theoretical and experimental result. On the basis of the prediction of the erosion profile, the applied parameters could be estimated.
Research on Tooth Trace Modification of Spur Bevel Gear
Authors: Yang Dong , Cui Huan Yong , Tian Xi Jie , Zhang Qing Ping
Published: June 2010

Based on the gear geometry theory and the normal meshing motion equation of gear pairs， changes of meshing points and angles are analyzed and the effect of tooth trace modification on gear pair meshing movement is discussed. It is concluded that chemical milling can effect tooth trace involute modification of fine-forged spur bevel gear, improve its surface quality and dimensional precision and therefore prolong its service life.
Microstructure and Tensile Properties of Al-(5~10)wt%Mg Alloy Sheets Fabricated by Twin Roll Casting and Rolling Process
Authors: Kim Hyoung Wook , Cho Jae Hyeng , Lim Cha Yong , Kang Suk Bong
Published: June 2010

High strength Al-Mg alloy strips with high Mg contents (5-10wt%Mg) were successfully fabricated by twin roll casting. In order to get a good surface quality of Al-Mg strips, an optimum process condition was investigated in this experiment. The morphology of the cast nozzle and the roll separate force during twin roll casting was important to improve the surface quality of the strip and homogeneity of the cast structure through the thickness. The size of intermetallic particle like Al-Fe compounds was reduced down to 1~2m due to a high cooling rate of Al melt during strip casting. In addition, the dendrite structure was very fine and the segregation of Al8Mg5 phase between grains was remarkably reduced. Therefore, the Al-Mg strips have good workability during additional cold/warm rolling processes. After annealing, the rolled sheets have superior tensile properties to a commercial high strength Al-Mg alloy sheet.
Wear Characteristics and Adhesion Behavior of Calcium Phosphate Thin-Films
Authors: Bin Abdul Shukor Mohd Hamdi , Toque J.A. , Ide-Ektessabi A.
Published: June 2010

Wear resistance is an important mechanical property expected from coatings intended for any type of applications. Understanding of this quantity is very practical because in real situations, coatings are subjected to repeating loads experienced not in a gradual orderly fashion but abruptly and indeterminately. This study looked into the wear characteristic and adhesion behavior of calcium phosphate, a known bioceramics, and hopes to provide better understanding of these properties. Radio frequency-magnetron sputtering (RF-MS) was used to deposit thin film (CaP) on glass. The coatings were subjected to single-pass microscratch and multi-pass wear test while monitoring the depth, load and displacement in situ. The results have shown that the changes in the surface topography can give an indication of the wear resistance of CaP. Coatings with good adherence to the substrate have shown less alteration of its surface roughness, measured in terms of Ra values, even after several scratch passes. The study on the different parameters revealed that deposition time is the most influential factor in CaP wear behavior. This was attributed to its correlation with coating thickness. Analysis of variance (ANOVA) also suggested that the other sputtering parameters studied in the experiments (argon pressure and RF power) did not have very significant effect on the wear pattern of the CaP thin films.
Effects of Substrate Bias Voltages on the Erosion Wear Resistance of TiN Coatings Deposited by Pulsed Filtered Vacuum Cathode Arc Deposition
Authors: Wu Feng Fang , Deng Jian Xin , Yan Pei
Published: June 2010

TiN coatings were produced on substrates of a hard metal at different bias by pulsed filtered vacuum cathode arc deposition assisted with ion bombardment. The erosion wear resistance of TiN coatings was investigated. The erosion wear was tested with a gas blast apparatus. In the test, TiN coatings were impacted at an impingement angle of 90° by angular SiC solid particles with an average diameter of 124um. The maximum depth of the erosion scar measured by the Veeco NT9300 optical profiler was used to evaluate the erosion wear loss of the coatings. The coatings proved to have lower erosion rate than the substrate material and consequently, the erosion rate increased significantly to the high level of the hard metal substrate after the coatings were penetrated. The results indicated that the TiN coating deposited at 150V bias had the lowest erosion wear rate and best wear resistance. The failure mechanism was revealed by examining the surface morphology of the coatings before and after the erosion test. The erosion wear of the TiN coatings behaved as typical brittle materials.
Major Factors in Rapid Prototyping of Mechanisms
Authors: Chen Yong Hua , Chen Zhe Zheng
Published: June 2010

Nowadays, layer based rapid prototyping (RP) technologies have been used not only to make product prototypes but also to manufacture small batch functional parts. For RP parts fabrication, build directions play an important role. There were many reports about optimal build directions for RP part fabrication, yet factors influencing build directions of mechanism joint have not been studied. This paper will look into the factors affecting build directions of mechanisms. A slider-crank mechanism is used as an example as it is the fundamental mechanism for many machine designs. Apart from factors affecting mechanism build directions, guidelines for mechanism joint design are also discussed.
An Experimental Study on Brazing of Diamonds onto Thin Steel Wires
Authors: Zhang Guo Qing , Huang Hui , Xu Xi Peng
Published: June 2010

An experimental investigation was carried out to braze diamond abrasives onto thin steel wires, in which case the brazing was conducted in the vacuum and under high temperatures by using a nickel-based powder as brazing alloy. The morphologies and microstructures of the brazed wires were observed and the comprehensive mechanical properties of the brazed wires were tested. The brazed wires were also used to cut such brittle materials as ceramics, glass, and natural stone. It is shown that a typical phenomenon of brazing alloy’s climbing around the diamond grains was observed in brazing the wires. Through observing the cross-section of brazed wires, it is observed that there is a good bonding between the brazing alloy and the body of steel wires. The crystal grains of the steel wires grew significantly after brazing. Through observing the morphologies of the diamond wires and the surfaces of four workpiece materials, few diamond pull-outs were found on the wires and the kerfs on the workpiece materials were basically flat.
Optimal Parameter Design of Solder Residue in Flip Chip Process by Using Taguchi Method
Authors: Kuo Jian Long , Chao Kai Lun , Kuo Chun Cheng
Published: June 2010

Because the solder residue was found in the manufacturing process which greatly affected the product quality, the purpose of this paper was to make the product quality improved and to find an optimal solution for process parameters in the flip chip process. The experimental testing was based on SMT manufacturing process. The amount and size of solder left on passive component in the process of manufacturing were considered as the quality traits. Since too many solders left on the passive component side during flux cleaning process, it was possible that the balling would be flowed into the chip, which caused the bump short in the chip and affected the quality of the product. In this paper, orthogonal array by using Taguchi method is adopted as the effective experimental method with the least experimental runs. Also, based on the quality evaluation of signal-to-noise ratio, the ANOVA is used to evaluate the effects of quality target according to the experimental results. The results reveal that the optimization in the process is confirmed. Therefore, this study can effectively improve the solder residue in semiconductor manufacturing process.
A New Solution Method for Homogenization of Effective Properties of Electromagnetic Honeycombs
Authors: Ma Lian Hua , Rolfe Bernard F. , Yang Qing Sheng , Yang Chun Hui
Published: June 2010

In this paper, an analytical model and its new numerical solution using the homogenization method are developed to determine the effective electromagnetic characteristics of honeycombs. Based on the proposed solution method, the electromagnetic properties are obtained by employing the multi-scale homogenization theory and periodical electric (magnetic) potential boundary conditions. Further, the effect of geometry of honeycomb’s unit cell on effective electromagnetic properties is investigated with the use of the proposed method. The numerical results are compared with analytic results using the Smith-Scarpa’s semi-empirical formula.
FEA-Predicted Subsurface Damage in Micro Finishing of a Feldspar Porcelain Using Fine-Grit Dental Burs
Authors: Song Xiao Fei , Yin Ling
Published: June 2010

Biocompatible ceramic structures are used to replace missing teeth, tooth structure lost to disease or trauma, and un-aesthetic healthy, tooth enamel. Recreating aesthetics and function are the two practical goals of such restorative treatment. However, the failure rate of ceramic prostheses is relatively high due to their inherent brittleness. A primary reason to premature failure of ceramic prostheses is surface and subsurface damage induced in dental intraoral finishing using dental handpieces and abrasive burs. In this paper, finite element analysis (FEA) was applied to predict quantitatively finishing-induced stress fields and subsurface damage depths in dental porcelain surfaces using fine grit diamond burs. The results indicate that while finishing using fine diamond burs diminished subsurface damage, damage depths of smaller than 20 m remained depending on the bur depth of cut and feed rate. In the FEA modeling, the minimum damage was obtained under very fine finishing conditions.
Production, Characterization and Application of Silicon-on-Sapphire Wafers
Authors: Pramanik Alokesh , Liu Mei , Zhang Liang Chi
Published: June 2010

Silicon-on-sapphire (SOS) thin film systems have had specific electronic applications because they can reduce noise and current leakage in metal oxide semiconductor transistors. However, there are some issues in producing defect-free SOS wafers. Dislocations, misfit, micro twins and residual stresses can emerge during the SOS processing and they will reduce the performance of an SOS product. For some reasons, research publications on SOS in the literature are not extensive, and as a result, the information available in the public domain is fragmentary. This paper aims to review the subject matter in an as complete as possible manner based on the published information about the production, characterization and application of SOS wafers.