bluuebunny/crossref_metadata_2025 huggingface dataset:
Methods for Prevention of Ignition during Machining of Magnesium Alloys
Authors: Hou Jun Zhan , Zhou Wei , Zhao Ning
Published: September 2010

Magnesium alloys have been increasingly used in automotive and aerospace components and in portable microelectronic devices due to their “ultralightness” and high specific strength. Machining is an important method used to process magnesium alloys. The advantages of machining over other processing methods such as die casting include reduction in power consumption and excellent surface finish. However, the ignition of chips presents a dangerous problem during machining. This problem has attracted considerable research interests. Though coolants can be used effectively to prevent ignition, the pollution of environment and reclamation of chips can not be resolved easily. Therefore, one better approach is to control the machining parameters for minimizing ignition hazard of magnesium alloy chips during dry machining. A systematic study was conducted for a few different magnesium alloys (including AM50A and AZ91D) to understand effect of cutting parameters (cutting speed, feedrate and depth of cut) on ignition of chips during face milling. It is interesting to find that for any fixed cut depth ignition in the forms of sparks, flares or ring of fire occurs only in the moderate cutting speeds and feedrates and can thus be easily prevented by adopting either higher or lower cutting speeds or feedrates. Chips produced in different machining conditions were collected and their morphology was analyzed to understand mechanisms of ignition.
Removal and Fracture Characteristics of Cemented Tungsten Carbide under Nanoindenting and Nanoscratching
Authors: Irwan Rudy , Huang Han
Published: September 2010

Nanoindenting and nanoscratching were used to investigate removal and fracture characteristics of cemented tungsten carbide (cWC). Nanoindentation results indicated that the elastic modulus and hardness of WC grains were significantly greater than those measured in cobalt binder rich regions, respectively. Few evidences of cracking or fracture were observed on the indented surfaces using both in-situ atomic force microscopy and scanning electron microscopy. However, the pop-in events were observed from indenting load-displacement curves and the corresponding acoustic emissions were detected, indicating the occurrences of brittle fracture. Nanoscratch results demonstrated that similar removal characteristics existed, but cracking was observed in both surface and subsurface of the scratched samples.
Development of 2DOF Ultrasonic Vibration Cutting Device for Ultraprecision Elliptical Vibration Cutting
Authors: Moriwaki Toshimichi
Published: September 2010

A new ultrasonic vibration cutting device for ultraprecision elliptical vibration cutting has been developed. The elliptical vibration cutting device developed utilizes combination of bending and longitudinal modes of vibration of the stepped vibrator to generate circular or elliptical vibration locus at the cutting tool edge. The design principle as well as the structure and the performance of the elliptical vibration cutting device is introduced here. The experimental results of diamond cutting of Co-Cr-Mo Alloy proved that good surface quality with roughness of 20 nmPV can be obtained stably with the elliptical vibration cutting device developed.
Reverse Simulation of Sinking EDM for Intricate Shapes
Authors: Kaneko Yuki , Kunieda Masanori
Published: September 2010

This research aims to develop a reverse simulation method to obtain the shape of tool electrode before machining from the shapes of workpiece before and after machining in sinking EDM. To apply the reverse simulation method to tool electrodes which have large curvatures, a special operation was added to the simulation program to consider the influence of the curvature. The validity of the principle of the modified reverse simulation was demonstrated in the machining of a V-shaped cavity.
Nickel Injection Mould Fabrication via Proton Beam Writing and UV Lithography
Authors: Liu Nan Nan , Shao Pei Ge , Kulkarni Shripad R. , Zhao Jian Hong , van Kan Jeroen A.
Published: September 2010

For applications of injection mould fabrication in the field of MEMS, proton beam writing (PBW) and UV lithography are combined to manufacture 2 mm thick Ni moulds with sub-10 µm fine features in 10 µm deep fluidic channels. PBW is capable of writing micro and nano features with straight and smooth sidewalls with sub-10 nm RMS roughness, while UV lithography has the advantage of large area structuring through a mask. A newly developed positive resist maP1275 hv is presented in combination with PBW and UV lithography for Ni injection mould fabrication. Fine micro pillars with straight and smooth sidewalls have been achieved by PBW and linked with UV lithography into a microfluidic channel. The new resist is successfully removed after electroplating without compromising the Ni mould.
Parametric Study of Micro Machining Three Dimensional Microstructure with the Tiny-Grinding Wheel Based on the EMR Effect
Authors: Gao Wei Qiang , Yan Qiu Sheng , Liu Yi , Lu Jia Bin , Kong Ling Ye
Published: September 2010

Electro-magneto-rheological (EMR) fluids, which exhibit Newtonian behavior in the absence of a magnetic field, are abruptly transformed within milliseconds into a Bingham plastic under an applied magnetic field, called the EMR effect. Based on this effect, the particle-dispersed EMR fluid is used as a special instantaneous bond to cohere abrasive particles and magnetic particles together so as to form a dynamical, flexible tiny-grinding wheel to machine micro-groove on the surface of optical glass. Experiments were conducted to reveal the effects of process parameters, such as the feed rate of the horizontal worktable, feeding of the Z axis, machining time and machining gap, on material removal rate of glass. The results indicate that the feed rate of the worktable at horizontal direction has less effect on material removal rate, which shows a fluctuation phenomenon within a certain range. The feed rate of the Z axis directly influences the machining gap and leads to a remarkable change on material removal rate. Larger material removal rate can be obtained when the feeding frequency of Z direction is one time per processing. With the increase of rotation speed of the tool, material removal rate increases firstly and decreases afterwards, and it gets the maximum value with the rotation speed of 4800 rev/min. The machining time is directly proportional to material removal amount, but inversely proportional to material removal rate. Furthermore, material removal rate decreases with the increase of the machining gap between the tool and the workpiece. On the basis of above, the machining mode with the tiny-grinding wheel based on the EMR effect is presented.
Research on Ultrasonic Vibration Combined with Grinding Machining and its Application in Processing Brittle Hard Materials
Authors: Zhang Yong Jun , Tang Yong Jun , Liu Xiao Kang
Published: September 2010

A system of ultrasonic combined with grinding has been designed, and one novel connective method of straight screw combined with taper surface has been applied in spindle, so compact size and high revolving accuracy can be achieved. Modal analysis of ultrasonic vibration system has been implemented by FEM (Finite Element Method), and its optimal dimension has been calculated to find out optimal vibration estate. Full-bridge converter has been applied in driving circuit of ultrasonic vibrator, and auto-frequency tracking has been designed in order that ultrasonic vibration works on resonant or quasi-resonant frequency. Finally, machining experiments have been fulfilled about ultrasonic combined with grinding, and its machining effect has been distinctly improved comparing ordinary grinding machining.
Deterministic Process Modelling of Micro Air Abrasive Jet Machining of Glass Channel
Authors: Wan Stephen , Fong Weng Seng , Leong Qi Ying
Published: September 2010

We present simple deterministic process models for the prediction of the evolution of the cross-sectional profile of glass channels generated by erosive wear in micro air abrasive jet machining using a round nozzle. The present work was motivated by a need to understand the sensitivity of the geometry of the generated cross-sectional profile to the degree of offset between the centre of the nozzle and the centre of the mask defining the channel. Experiments were carried out on soda lime and borosilicate glass to verify the process models. Predicted results show fairly good agreement with experimental results. We conclude that, without proper alignment, the cross-sectional profile is easily skewed, as the micro abrasive jet machining process quickly acts on any initial geometrical skewness and compounds it over time.
Performance of Bunched-Electrode in EDM
Authors: Gu Lin , Li Lei , Zhao Wan Sheng , Rajurkar K.P.
Published: September 2010

This paper aims to introduce the performance of bunched-electrode for die-sinking EDM. Bunched-electrode was formed by bunching numerous hollow cell-electrodes together to generate an electrode in which end surface matches the final surface of the mould cavity. FEM analysis and experiments were conducted to demonstrate the feasibility and effectiveness of bunched electrode in ED machining. Experiments show that while machining with bunched-electrode, it is feasible to apply a much higher peak current to achieve higher MRR. Meanwhile, a special phenomenon called shallow radial craters in machining with bunched-electrodes was observed and analyzed. One possible reason may be that the plasma columns in the gap are distorted outwards by strong inner pressure flushing.
The Tool Path Generation by Using Configuration Space for Five-Axis Controlled Machining - Application to Rough Cutting by Using Square End Mill -
Authors: Masuda Takuya , Morishige Koichi
Published: September 2010

In recent years, five-axis controlled machine tool attracts attention from the increase in demand for improvement of productivity. Five-axis controlled machine tool which is added two axes for rotating and tilting to three translational axes, and can give arbitrary tool attitudes for a workpiece.
Gear Precision and Cutting Force in Dry Hobbing Gear Cutting for Gears Made of Brass Material
Authors: Abe Tatsuro , Fukunaga Keigo
Published: September 2010

Gear precision measurement was carried out for gear with tooth number z=17, gear module mn=0.5, tooth width b=10mm, spur gear design and made using JIS C 3604 brass material. Cutting force measurement was carried out for gear with z=30, mn=1.75, spur gear, and JIS C 3604 brass material. Main results are as follows: (1) Gear precision and cutting force was almost the same in both dry and wet cutting. (2) Process capability index Cp of tooth profile errors were almost the same in both dry and wet hobbing gear cutting, and 5.9 to 8.1. Cp of tooth lead errors was 5.8 to 10.7. It was concluded that dry hobbing gear cutting of brass material has a sufficient production capacity. (3) Almost the same gear precision in both dry and wet hobbing gear cutting was considered because cutting forces were also same.
Integrated Production Planning, Scheduling and Shop Floor Tracking System for High-Mix Low-Volume Manufacturing - A Consortium Approach
Authors: Chua Tay Jin , Tan Chak Huah , Cai T.X. , Phua G.H. , Aw Leck Leng , Huang Y.L.
Published: September 2010

In Singapore, the Precision Engineering (PE) industry is the backbone of the manufacturing sector; it supports a large number of manufacturing industries such as Electronics, Chemicals, Pharmaceuticals, Biotechnology, Aerospace, Oil & Gas and Automotive. From our recent visits to companies in the PE industry, it was observed that given such a dynamic and stochastic manufacturing environment, most of these PE companies are still predominantly using Microsoft Excel as their planning & scheduling tool, shop floor tracking is normally performed manually through paper traveler, and production status is only updated at the end of the day or as and when demanded by customer. The common problems highlighted include inability to provide realistic delivery commitment, machine and manpower resources are not optimally utilized to fulfill customer orders, unacceptable order cycle time and lack of production visibility. Therefore, there is an increasing demand and impending need for a computerized integrated production planning/scheduling and shop floor tracking system. In this paper, a consortium approach for the development of an integrated production planning/scheduling and shop floor tracking system for the High-Mix Low-Volume (HMLV) PE environment is presented. An illustration through the implementation of the proposed system in a PE company is highlighted. With this system, companies would be able to improve their delivery performance through effective handling of ad-hoc customer orders and the ability to react to deviations or unplanned events in production.
Effects of Crystallographic Structure on Machining Performance with Polycrystalline Oxygen Free Copper by a Single Crystalline Diamond Micro-Tool
Authors: Ding X. , Lee L.C. , Butler David Lee , Shaw Kah Chuan
Published: September 2010

A study was carried out to investigate effects of crystallographic structure on the machining performance with polycrystalline oxygen free copper (OFC) using a single crystalline diamond (SCD) micro-tool. The SCD micro-tool used in this study fabricated with a focused ion beam (FIB) has a cutting length of around 30 µm on the primary clearance face. It was found that a change in crystallographic orientation resulted in a variation in machining force, chip thickness and shear angle, leading to a change in machined surface integrity. When a micro-size tool traverses within a grain at a machining direction aligned with a particular crystallographic orientation, the work material in front of the machining tool is found to be severely deformed. If the orientation changes to a less favorable orientation, this may lead to a much reduced shear angle, a thicker chip, striation at the chip back, higher machining forces and a degraded machined surface. This study contributes to the understanding of the physics of micro scale mechanical machining (micro-machining).
Design Approach for Jig in Computer Assisted Total Knee Replacement Surgery
Authors: Sulong Abu Bakar , Chua Abdullah Muhammad Ilman Hakimi , Abdullah Mohd Fazuri , Koon San Wei , Yahya Nor Hamdan Nor , Ramli Rizauddin
Published: September 2010

During performing Computer assisted Total Knee surgery, surgeons have difficulties in orientation of cutting block before sawing procedure. The objectives of this study are develop design approach and fabrication of prototype, which able to eliminate stated difficulties. Thus, improve performance and cycle time of total knee surgery. Benchmarking with commercial product had been conducted, two designs of jig system were proposed. Selection of design was conducted using Pugh method. Two designs were compared based on specific requirements, in order to get the most acceptable design. Pugh method analysis shown that the second design give more advantages in handling, easy to operate, least cost in manufacture, and reduction of time in doing the total knee replacement than the first design. Prototype jig assembly consist of arm, base and cutting block were fabricated by rapid protyping for feasibility analysis. Then, simulation of fabrication by machining process was conducted through Mastercam Mill V8. All component were able to fabricated through machining. A prototype of jig system was fabricated using stainless steel typed SS316L, and evaluation of cutting procedure with saw bone confirmed that the second design is fulfill the objectives of this study.
Ultraprecision Microgrooving of Hard Material by Means of Cutting Point Swivel Machining
Authors: Tang Xin Rui , Yoshinaga Miki , Nakamoto Keiichi , Ishida Tohru , Takeuchi Yoshimi
Published: September 2010

Recently, in accordance with the technical development and miniaturization of the information equipments, the demand of optic elements with high precision and miniaturization is increased. The die is used for manufacturing the optic elements. Thus, it is needed to machine the die with high efficiency and high precision. As the material of die, hard material including cemented carbide and ceramics is used. However, when hard material is machined, there is a problem that severe tool wear occurs, and worn tool shape is transferred into the surface so that precision machining cannot be realized. In this study, a method, called cutting point swivel machining, is proposed to suppress tool wear by using the tool with special chamfer and all parts of tool tip. The effect of tool wear suppression is verified by the machining of SiC. Then, the relation between the suppression of tool wear and tool rotation period is verified.
Improving the Sensitivity of T-Shape Test to Friction Conditions for the Evaluation of Friction Behaviour in Microforming
Authors: Taureza Muhammad , Castagne Sylvie , Aue-U-Lan Yingyot
Published: September 2010

In this paper, the sensitivity of T-Shape test to friction conditions was evaluated by observing the extrusion height and load curves throughout the normalized stroke (relative to workpiece diameter). Using the finite element code Deform 2D and assuming plane strain approximation, the effects of changing die geometry to the T-Shape test results were investigated. The sensitivity of the T-Shape test was also improved by introducing the double-sloped T-Shape design. The double-sloped T-Shape test was able to separate the extrusion height curves for shear coefficient of friction 0.0 to 0.4 which was unable to distinguish using the original T-Shape setup.
Feasibility Study on Producing Components with Embedded Channel by Powder Injection Moulding
Authors: Zhang Su Xia , Ong Zi Yan Amanda , Li Tao , Li Q.F. , Ng Fern Lan
Published: September 2010

Feasibility study on producing components with embedded channel by powder injection moulding (PIM) is conducted in this paper. The base plate with open channel was produced by co-injection moulding of polymeric material and ceramic feedstock. The polymeric material acted as the sacrificial material to fill the channel feature. A cover plate was then over-moulded onto the base plate to form green assembly, which was then debinded and sintered. The embedded channel was created when the sacrificial material was removed during the debinding and sintering stage. This process eliminates the need for additional joining process required by conventional manufacturing process which could cause misalignment and leakage under harsh working environment such as high pressure and high temperature. Joining was found between the cover plate and the base plate in over-moulding stage. Temperature and time during solvent debinding played important roles in order to obtain defect free component. Low temperature and short time in solvent debinding resulted in insufficient wax loss which led to various types of defects. A fair good sintered component was obtained under optimal debinding condition at 50 °C for 48 hours. The embedded channel was observed clearly by x-ray inspection without blockage by foreign particles. The shape of the channel was well retained and perfect bonding was formed in the central area of the two plates.
The Effect of One Directional Ultrasonic Vibration Assistance in High Speed Meso-Scale Milling Process
Authors: Ko Jeong Hoon , Shaw Kah Chuan , Chua Han Kwang , Lin Rong Ming
Published: September 2010

One-directional ultrasonic vibration assisted milling system is designed and its performance is investigated in terms of machined surface quality under 135,000 rpm. The ultrasonic vibration generator excites the workpiece with a frequency around 40 kHz and amplitude of a few micro meters. The milling tool’s cutting speed is controlled by an air-bearing spindle system. Both feed-directional and cross-feed directional ultrasonic vibration assistance are considered in order to understand the mechanism of ultrasonic vibration assistance for surface roughness generation. A comparison is done on a milled surface which is generated with and without ultrasonic vibration assistance. The experimental results show that ultrasonic vibration assistance can improve the machined surface quality which depended on the cutting edge radius and the feed per tooth.
Spin Formability of Al-6061 Aluminum Alloy Pre-Forms Obtained via Liquid Forging
Authors: Su Chun Wei , Oon Peng Hooi , Fong Kai Soon , Sina Hossein , Wong Chow Cher
Published: September 2010

There are growing demands from the precision engineering industries for components that are net or near net shape while striving to reduce material wastage during the manufacturing process. This study investigates the spin formability of liquid forged Al-6061 pre-forms into near net shape cylindrical components with high aspect ratios. The liquid forging process offers very significant materials savings by providing pre-forms for the spin forming process. The end products are near net shape components with very good mechanical properties. Results from this study indicate that liquid forging is able to supply Al-6061 pre-forms, otherwise machined from solid bars, which are sufficiently formable for spin forming. The microstructure of a spin formed liquid forged pre-form is also indiscernible from that of a fully machined pre-form from extruded bar stock. As such, spin forming of liquid forged pre-forms has the potential to reduce material wastage and hence production costs.
Investigation of Process Parameters in Superplastic Forming of Mechanical Pre-Formed Sheet by FEM
Authors: Liu Jun , Tan Ming Jen , Castagne Sylvie , Aue-U-Lan Yingyot , Fong Kai Soon , Jarfors Anders W.E.
Published: September 2010

Conventional superplastic forming has been applied in automotive and aerospace industries for a few decades. Recently, superplastic forming combined with mechanical pre-forming process has been reported to be capable of forming non-superplastic AA5083 at 400 °C to a surface expansion of 200 % [1]. In this paper, finite element modeling (FEM) was used to develop the combined forming process by using the non-superplastic material AA5083-O. The simulation follows the experimental sequence and was divided into two phases (mechanical pre-forming and superplastic forming). A conventional creep equation based on tensile test data was adopted as a material model for the simulation. The pressure cycle and forming time was simulated according to the actual process route. The thickness distributions obtained from simulation validated the capability of the model to be used for this case. The influence of different parameters, such as holder force, friction, and punch depth was investigated by comparing the final sheet thickness and level of material draw-in. It was found that the punch depth played a significant effect on the uniformity of thickness distribution, from which a more uniform formed part can be obtained by using the punch with higher depth during mechanical pre-forming phase.
Development of CAD System Based on Function Features
Authors: Ando Sonken , Ikeda Ryo , Aoyama Hideki , Hiruma Norihito
Published: September 2010

Three-dimensional CAD systems contribute considerably to the detailed design processes of products. They are applied to the construction of 3D design models which are also utilized for design evaluation using a CAE system and for NC data generation using a CAM system. Since the functions of 3D CAD systems for constructing 3D models are increasingly being enhanced, they enable designers to easily construct 3D product models without design expertise. In detailed design work, designers are required not only to exactly define product shapes but also to assign attribute information such as dimensional tolerance, geometrical tolerance, roughness, machining process to be performed etc., which are essential for the manufacturing process. However, inexperienced designers often find it extremely hard to determine optimum attribute values and design values. In addition, it is more difficult to construct the required die/mold from the desired product shape taking into account forming errors caused by shrinkage during plastic injection and springback during press forming. This paper proposes a method to automatically assign required attribute information to each part of a designed product, to assist the model construction of a die/mold from a product shape, and to provide design support information on each part of a designed product to a designer. The proposed method is realized by assigning a Function Feature to each part; all the function features proposed in this paper are original. A CAD system based on the proposed method for injection molding and press forming was developed, and results of simple design experiments confirmed the usefulness of the CAD system and function features
Joint Formation Mechanism and Strength in Resistance Microwelding of Brass Sheet to Fine Insulated Cu Wire
Authors: Mo Bing Hua , Guo Zhong Ning , Li Yuan Bo , Liu Chang
Published: September 2010

Resistance microwelding is an important microjoining process used in the fabrication of microelectronics, MEMS and medical devices. However, the process is infeasible in the situation of terminating insulated copper wire to metal sheet due to the hindrance of the insulation coating in common opposed configuration. To address this problem, a revised electrode configuration is used. The effect of main process parameters (welding current, weld time and electrode force) were investigated by detailed mechanical testing and metallurgical examinations. A bonding mechanism with several main process stages (wire cold collapse, coating melting and withdrawing, and solid-state bonding) was proposed.
Electrostatic Control and the Need of Feedback Control Ionization in Critical Environment of MEMS Manufacturing Process
Authors: Chakkaew Anusorn , Titiroongruang Wisut
Published: September 2010

This paper describes new electrostatic control countermeasures and solutions for critical electrostatic control environment for MEMS manufacturing processes, especially in MEMS’s wafer handling that needs low electrostatic voltage. This includes personnel grounding methodology, ESD event measurement, and low ion imbalance ionization to support current and future needs of the MEMS.
An Multi-Axis Spindle for Automated Coaxial Alignment
Authors: Chen Wen Jie , Lin Wei , Luo Hong , Wong Lye Seng , Yang Gui Ling
Published: September 2010

Coaxial alignment is an important process in the machining of cylindrical-shape miniature components with an inner bore. It requires aligning the axis of the inner bore with respect to the machine rotational axis precisely. In this paper, we present a spindle with automated coaxial alignment capability for machining applications of the components such as ferrules and capillaries. This spindle includes a novel orientation-adjustable mechanism and a vision-guided feedback system. The adjustment mechanism consists of two pieces of flexural bearings, which can provide the spindle with 4 DOF adjustments without any backlash. The vision-guided feedback system comprises the component face image processing and the through-bore light intensity processing, both of which provide the information of translational and angular offsets. A prototype of the spindle was built to verify the technology we developed. The results show that the system can achieve superior coaxial alignment performances.
An Optical Fiber Probe for 3-D Micro Metrology
Authors: Murakami Hiroshi , Katsuki Akio , Onikura Hiromichi , Sajima Takao , Kawagoishi Norio , Kondo Eiji , Honda Tomohiro
Published: September 2010

This paper presents a system of 3-D micro structure measurement that uses an optical fiber probe of 5 µm in diameter. The probe is deflected when it comes into contact with a measured surface, and this deflection is measured optically. In this research, we optimize design parameters of optical system using ray tracing, and a prototype of the measuring system is fabricated on trial to verify the simulation results. Then, its measuring accuracies are examined by using the basic experimental apparatus. As a result, it is clarified that the resolution of the fiber probe is better than 10 nm. Also, the utility of this system is confirmed by measuring the shape of a 600 µm diameter ruby sphere.
Design of Digital Filters for Si Wafer Surface Profile Measurement - Noise Reduction by Wavelet Transform -
Authors: Ono Masashi , Nonomura Kazutaka , Zhou Li Bo , Shimizu Jun
Published: September 2010

Recently in semiconductor industry, production of ever flatter, thinner and larger silicon wafers are required to fulfill the demands of high-density packaging and cost reduction. In geometric evaluation of Si wafers, according to SEMI (Semiconductor Equipment and Materials International) standards, the required wafer flatness approaches to the 22 nanometers by year 2016 [1]. For such application, uncertainty of measured data is encountered as a severe problem because high resolution instrument always incorporate a certain degree of noise. In order to precisely evaluate the wafer profile, it is essential to remove the noise from the measured data. Described in this paper is design and development of digital filters for denoising. Compared to the conventional low-pass filters, the developed filter by use of wavelet transform not only provides better performance of decomposition in the spatial frequency domain, but also offers the new capability of denoising in amplitude domain.
Uncertainty Estimation in Intelligent Coordinate and Profile Measurement
Authors: Takamasu Kiyoshi , Takahashi Satoru , Chen Xin
Published: September 2010

The uncertainty estimation of coordinate and profile measurement is essential for accurate measurement and establishment of traceability. We proposed an uncertainty propagation method to estimate the uncertainty of coordinate and profile measurement. In this article, the multi sensor algorithm with uncertainty estimation method is described for the profile measurement. Additionally, two examples of multi sensor method are introduced. According to the simulation results of assessing uncertainty and the experimental results, the validity of the method was confirmed.
Plasmonic Lens for Nanometrology
Authors: Wang Jun , Zhou Wei
Published: September 2010

In this paper, we presented plasmonic lens using metallic nanostructures to manipulate light based on surface plasmon polaritons for subwavelength focusing and collimation. We then proposed the use of plasmonic lens in the field of nanophotonics as a micro-photonic-device for nanometrology and sensing/detection purposes.
Development of In-Process Evaluation for Microlens Mold Using Angle Resolved Scattering System
Authors: Hayashi Terutake , Yuki Nakatsuka , Takaya Yasuhiro
Published: September 2010

If the surface of a lens injection mold contains defects, the conditions of its surface coating worsen with each injection in the lens production process. Hence, an on-machine quantitative evaluation method is required for the lens mold surface. With the aim of characterizing the mold surface texture in this study, we have developed an automated light-scattering measurement system that enables 3D detection of scattered light in various directions due to the flaws and roughness of the mold surface.
Fiber-Spiral Microstructures of Bamboo and Biomimetic Research
Authors: Chen Bin , Yuan Quan , Luo Ji
Published: September 2010

The microstructures of a whangee (a kind of bamboo) were observed with a scanning electron microscope (SEM). It showed that the whangee is a kind of natural cellular biocomposite consisting of countless bamboo cells. The bamboo cells are columnar and all of them are parallel with the surface of the bamboo. The observation also showed that the walls of the bamboo cell are a kind of fiber-reinforced biocomposite with bamboo fiber-spiral mcirstructure. Based on the SEM observation, a kind of biomimetic composite with the fiber-spiral structure was fabricated. The fracture toughness of the composite was investigated and compared with that of the conventional composite with parallel-fiber structure. It showed that the fracture toughness of the biomimetic composite is markedly larger than that of the conventional composite.
Fabrication of Dense Composite Ceramic Electrolyte SDC-(Li/Na)2CO3
Authors: Jarot Raharjo , Muchtar Andanastuti , Wan Daud Wan Ramli , Muhamad Norhamidi , Majlan Edy Herianto
Published: September 2010

Composite electrolytes made of samarium-doped cerium (SDC, Ce0.8Sm0.2O1.9) and (67 mol% Li/ 33mol% Na)2CO3 carbonate salts were investigated in relation to their structure, morphology and porosity of the electrolyte. The fabrication of the SDC–(Li/Na)2CO3 composite electrolytes were achieved in two steps: step (1) preparation of the samarium-doped cerium powders by sol-gel; step (2) mixing of the samarium-doped cerium with carbonates in various compositions by solid state reaction. The electrolyte pellets were compacted at different pressures (25 and 50 MPa) and sintered at 600oC, 700oC and 800oC. The XRD results demonstrated that the introduction of carbonates did not change the SDC phase structure. FESEM images showed that the carbonate component was amorphous and well distributed in the SDC. The lowest porosity (2.92%) was achieved for samples with carbonate content of 30% (SDC7030) sintered at 800oC and cold pressed at 50MPa.
Optimisation of Processing Parameters of Titanium Foams Using Taguchi Method for Compressive Strength
Authors: Ahmad Sufizar , Muhamad Norhamidi , Muchtar Andanastuti , Sahari Jaafar , Jamaludin Khairur Rijal , Ibrahim Mohd Halim Irwan , Nor Nor Hafiez Mohamad
Published: September 2010

In this paper, titanium alloy was used to prepare titanium foam using the slurry method. The compressive strength is the most important properties to be considered to produce a good sample. To achieve a high compressive strength of the titanium alloy foam, the effects of various parameters including temperature, time profile and composition have to be characterised and optimised. This paper reports the use of the Taguchi method in optimising the processing parameters of pure titanium foams. The effects of four sintering factors, namely, composition, sintering temperature, heating rate and soaking time on the compressive strength has been studied. The titanium slurry was prepared by mixing titanium alloy powder, polyethylene glycol (PEG), methylcellulose and water. Polyurethane (PU) foams were then impregnated into the slurry and later dried at room temperature. These were next sintered in a high temperature vacuum furnace. The various factors were assigned to an L9 orthogonal array. From the Analysis of Variance (ANOVA), the composition of titanium has the highest percentage of contribution (64.64) to the compressive strength followed by the soaking time of sintering factor (6.01). The optimum compressive strength was found to be 38.03 MPa for this titanium alloy foam. It was achieved with a 750% composition of titanium, sintering temperature of 1250oC, a heating rate of 1.5oC/min and 120 minutes of soaking time.
Surface Modification of AZ91D Magnesium Alloy Using Millisecond, Nanosecond and Femtosecond Lasers
Authors: Guan Ying Chun , Zhou Wei , Zheng Hong Yu , Li Zhong Li
Published: September 2010

Poor surface properties of magnesium alloys limit their extensive use in many applications. Laser surface engineering can be used to enhance surface-related properties of Mg alloys, and the purpose of this paper is to study the effect of laser pulse duration on surface of AZ91D Mg alloy. After millisecond-pulse laser treatment, ripples and cellular/dendrite as well as nanoscale -Mg17Al12 precipitates in the -Mg matrix were found in the surface microstructure, moreover, the melt depth was more than 150 micron. After nanosecond-pulse laser treatment, craters of 10 to 50 micron in diameter were observed on the surface due to plasma expansion and melted matter ejection during local boiling process, and the melt depth was nearly 15 micron. However, femtosecond-pulse laser treatment produced various micro- and nano-structures within a very thin layer on the surface.
Thermal Conductivity of CrAlN and TiAlN Coatings Deposited by Lateral Rotating Cathode Arc
Authors: Samani M.K. , Chen George C.K. , Ding Xing Zhao , Zeng Xian Ting
Published: September 2010

CrAlN and TiAlN coatings were deposited on stainless steel substrates by a lateral rotating cathode arc technique. The composition and structure of the as-deposited coatings were analyzed by energy dispersive analysis of X-rays (EDX) and X-ray diffraction (XRD). Thermal conductivity of these coatings is measured using pulsed photothermal reflectance (PPR) technique at room temperature. The measured thermal conductivity of pure TiN coating is around 11.9 W/mK. With increasing Al content, thermal conductivity of the TiAlN coatings decreased significantly and a minimum value of about 4.63 W/mK was obtained at the Al/Ti atomic ratio around 0.72. With the increase of Al content, thermal conductivity of CrAlN coatings decreased slightly but consistently. The variation of thermal conductivity in these coatings is explained in term of phonon scattering on grain boundaries and local strain centers caused by lattice distortion. In comparison with TiAlN, thermal conductivity of CrAlN coatings was evidently lower, which could be partially responsible for their better performance in high speed machining applications as observed in our previous work.
Fabrication of Binder-Free Green Composite Using Bamboo Fibers Extracted with a Machining Center
Authors: Ogawa Keiji , Hirogaki Toshiki , Aoyama Eiichi , Taniguchi Mitsuaki , Ogawa Sachiko
Published: September 2010

Bamboo grows faster than other renewable natural materials. Bamboo fiber, in particular, has attracted attention as an environmentally superior material. Therefore, we proposed a sustainable manufacturing system using bamboo. An extraction method of bamboo fibers end-milled using a machining center with in-situ measurement is proposed. Bamboo fibers with high precision shape are efficiently acquired. In the present report, we propose the fabrication of binder-free composite by a hot press forming method that only uses bamboo fibers extracted by a machining center. We experimentally demonstrated various hot press forming conditions and achieved proper forming conditions to optimize the forming process. We also made various three-dimensional shapes considering the practical applications of the formed binder-free bamboo fiber moldings.
Nickel-Hydroxyapatite as Biomaterial Catalysts for Hydrogen Production via Glycerol Steam Reforming
Authors: Lukman Hakim , Yaakob Zahira , Manal Ismail , Wan Daud Wan Ramli
Published: September 2010

Nickel-hydroxyapatite as biomaterial catalysts exhibited high activity and selectivity in glycerol steam reforming. The catalytic steam reforming of glycerol (C3H8O3) for the production of hydrogen is carried out over nickel supported on hydroxyapatite [Ca5(PO4)3(OH)] catalyst at 600 oC with atmospheric pressure and 120 minute time reaction. The catalysts were prepared by mean of wet impregnation method and varied nickel loadings (3, 6, 12 %) on hydroxyapatite. It is found that the 3% wt% Ni/HAP show higher hydrogen production rate over the other nickel loadings on hydroxyapatite, which is correlated with Ni/HAP catalyst surface area measured by BET adsorbtion and morphology of catalysts. Glycerol steam reforming with water-to-glycerol feed ratio 8/1 much more hydrogen production (77-82%) compared feed ratio 4/1. The catalysts were characterised by BET surface area and SEM-EDX techniques.
Properties of Test Coupons Fabricated by Selective Laser Melting
Authors: Liu A. , Chua Chee Kai , Leong Kah Fai
Published: September 2010

Selective Laser Melting (SLM) is a popular and promising Additive Manufacturing (AM) technique as it can produce parts with complex internal features with part density close to 100%. However, unprocessed raw SLM fabricated parts have surface roughness issues and the mechanical properties of raw SLM parts without heat treatment are not ideal. The material used to address some of these issues in this research is an Aluminum alloy, AlSi10Mg – a strong and light weight metal. The SLM machine engaged for the test coupons fabrication is M2 Cusing from Concept Laser, Germany, which uses a diode pumped Yb-Fibre laser (Ytterbium-doped fibre lasers) with an effective output power of 200W. It is found that SLM fabricated parts with and without sandblasting shows up to 80% difference in surface roughness values. Also, the tensile test experiments of raw untreated SLM parts carried out at room temperature and at high temperature (200oC) show superior result compared with heat treated casted parts. Other properties such as hardness and density (porosity) are found to be better than heat treated cast parts as well.
Effects of Molding Parameters and Addition of Fillers on Gate Chip Off Formation during the Degating Process in Transfer Molding
Authors: Sulong Abu Bakar , Keong Gan Tek , Sahari Jaafar
Published: September 2010

In the electronics packaging industry, Epoxy Mold Compound (EMC) polymer matrix is filled with fused silica (SiO2) to obtain the required roughness and hardness. Gate chip off, which occurs during the degating process in transfer molding is one of the common defects which contributes to the failure in the proper functioning of the package. During the degating process, surface contact between two solid bodies (degating blade and gate) generate a high shear stress on package, thus creating a high potential for the incidence of gate chip of. In this study, the influence of transfer molding parameters and size of fillers (normal and fine) on the gate chip off were investigated. The application of Design of Experiments (DOE) using regression model and Analysis of Variance (ANOVA) showed that molding parameters do not significantly influence the incidence of gate chip off. Numerical simulation was used to investigate effect of two filler sizes and molding parameters on the mold fill time, end pressure of fill and shear stress at the wall. The results showed there were no significant influences on mold fill time but the fine filler showed lower pressure at the end of fill and lower shear stress at the wall. Experimental results of two sizes if filler shown that fine filler mold compound exhibited in reduction of gate chip off formation, compared to normal filler mold compound. Smooth surface of fine mold compound lead to decrease of friction shear stress during degating is expected contribute to this finding.
Driving – A Flexible Manufacturing Method for Individualized Sheet Metal Products
Authors: Scherer Daniel , Yang Z. , Hoffmann H.
Published: September 2010

This paper provides general information about the qualification of driving as an on-demand manufacturing concept for the production of individualized sheet metal products. Driving allows the creation of almost any 2D or 3D geometry, but it is a highly interactive, manual production process. Due to the inevitable variations of the incremental forming process (mechanical properties, tribology, wear etc.) and the high number of forming steps, it cannot be automated by traditional approaches. At the Institute of Metal Forming and Casting (Technische Universitaet Muenchen) a kraftformer machine has been equipped with measuring and controlling instrumentation. An optical online measurement system is installed to detect any geometry deformation of the current work piece and to visualize the deviation between the actual and the stored reference geometry during the whole production process. This variance comparison is the first step for planning any following incremental forming actions based on acquired and/or learned knowledge. The second step is the integration of an industrial robot for work piece handling and the automation of the whole manufacturing process. The last step is the integration of neural networks to predict production strategies for any desired unique geometry.
Thermal Behavior and Tool Failures on Rotary Cutting of Difficult-to-Cut Materials Utilizing Multi Tasking Lathe
Authors: Yamamoto Hiromasa , Satake Kentaro , Sasahara Hiroyuki , Narita Toru , Tsutsumi Masaomi , Muraki Toshiyuki
Published: September 2010

In rotary cutting difficult-to-cut materials, less tool wear is observed at higher cutting speeds, contrary to the case of conventional single-point turning. In order to examine this characteristic feature of rotary cutting, this study focuses on the effects of cutting speed and tool peripheral speed on tool failure. Dry rotary cutting tests of stainless steel SUS304 were carried out using coated carbide tools. Cutting speeds were set at 100 m/min, the speed typically recommended for conventional turning, and 500 m/min. At 100 m/min, adhesions and subsequent chippings were observed on the cutting edges. Meanwhile, at 500 m/min the higher average temperature at the tool-workpiece contact area caused small wear spots, rather than adhesions at the optimized tool speed. Hence, for rotary cutting, a higher cutting speed is more effective in terms of both achieving several-times-higher productivity and reducing the amount of tool failure due to the difference of tool failure modes.
Development of Flexible Worktable for Endmilling Based on Parallel Mechanism
Authors: Tanaka Tomohisa , Komori Masahiro , Zhu Jiang , Saito Yoshio
Published: September 2010

Parallel mechanism has many advantages, such as high stiffness, high accuracy, high degree of freedom (DOF), etc. These fine features are suitable for work table of machine tools for production of recent complicated designs. In this study, six axes linear-actuated parallel mechanism was chosen as the basic design for work table. First, geometrical parameters of the table were designed to satisfy the required movable range with minimum cutting load. Then, the work table was actually constructed and its performance was evaluated. From positioning accuracy measurement, it was found that the table is suitable to be used for machining of complicated products. On the other hand, from actual cutting tests of primitive shapes using chemical wood and measurement of the machined shapes, potential of the table for real cutting application was confirmed.
Compound Micro/Nano Machining – A Tool-Based Innovative and Integrated Approach
Authors: Rahman Mustafizur , Asad A.B.M.A. , Masaki T. , Wong Yoke San , Senthil Kumar A.
Published: September 2010

Compound micro-machining is the most promising technology for the production of miniaturized parts and this technology is becoming more and more important and popular because of growing demand for industrial products with not only increased number of functions but also of reduced dimensions, higher dimensional accuracy and better surface finish. In this paper, the development efforts in micro/nano-machining based on solid tools (tool-based micro/nano-machining) in NUS are introduced. In order to achieve meaningful implementation of micro-machining techniques, this research seeks to address four important areas; namely (a) development of machine tool capable to do both conventional micro-machining, (b) process control, (c) process development to achieve necessary accuracy and quality, and (d) on-machine measurement and inspection. An integrated effort in these areas has resulted in successful fabrication of micro-structures that is able to meet the miniaturization demands of the industry. In the area of nano-machining machine tool and process developments have also been carried out for electrolytic in-process dressing (ELID) grinding and ultra precision machining using single point and poly crystalline diamond tools to produce nano surface finish on hard and brittle materials. An ultra-precision diamond turning machine has been developed which incorporates a fast and fine tool servo system to produce nano-precision surfaces and features.