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The formability of sheet-metal with a folding-bottom circular hollow tube has been studied both by numerical simulation and experiment. A mesh-convergence analysis has been carried out to determine an optimum element size for purposes of numerical simulation. The geometry and dimension of the dies and of the punch are designed to simulate the multi-stage deep drawing operation to take place. During the deep drawing operation, the strains of the sheet blank are always located in the second quadrant of the forming limit diagrams, and it continuously moves in a linear state to the left side of the diagram. At the final stage, the tube is drawn to a certain height without evidence of fracture. In order to obtain a quality product, an optimization of input parameters for the deep drawing operation is conducted using Taguchi method. Finally, a validation test is also employed to demonstrate the accuracy of forming processes. The result reveals sufficient agreement in both geometry and dimension between simulated and actual tubes to meet a good quality standard.

Automated dimensional inspection is commonly expensive because of the requirement of high-precision measurement devices. To perform a precision measurement, the technician must be highly skilled and fully understands the operation of the equipment. This study proposes a method for reconstructing the two-dimensional profiles of ring-shaped objects using image processing. At first, an industrial camera captures partial images of the object. After that, through several image processing procedures such as binarization, line detection, and contour recognition, the profiles in the images were detected and grouped. Then, a calibration model was introduced to calibrate and combine the contours from partial images. This process results in a point cloud consisting of every point from the outer and inner contours of the object, which can be directly used for the automatic measurement. To verify the proposed method, the data were compared with those acquired from the ATOS measurement system, revealing a favourable correlation.

Magnetic particle inspection is typically used to detect the magnetic leakage caused by defects. This method is mainly used to detect the surface and subsurface defects of ferromagnetic materials. The conventional detection method involves inspectors performing visual inspection under high-power ultraviolet light. However, the intense ultraviolet light can easily damage the eyes of the inspectors. Furthermore, the aforementioned process is not only time consuming but also susceptible to human errors. Therefore, this study developed an automated optical inspection system to perform magnetic particle inspection. Analysis of several image features revealed that a contour compactness between four and five can be used to distinguish defective and non-defective features effectively. The defect identification ability obtained with several input combinations of image features for neural networks was analyzed. The results revealed that a high identification ability can be achieved for defective features when the input combination of area, mean width, and compactness is used.

In this study, the efficiency of minimum quantity lubricant (MQL) was demonstrated during hard-milling of AISI H13 steel with a carbide-coated (TiAlN) cutting tool. A comparative analysis was done to prove the effectiveness of MQL versus the dry cutting method based on certain process parameters such as surface roughness and cutting force. The L27 orthogonal array of the Taguchi method was used for designing the experiment. An analysis of the influence of cutting parameters including cutting-speed, feed-rate, depth-of-cut and hardness-of-workpiece on the cutting force and the surface roughness was carried out by using the response surface methodology (RSM) and analysis of variance (ANOVA). The result shows that under both of the cutting conditions (MQL and dry), feed rate and depth-of-cut are main factors affecting surface roughness and cutting force. Further, quadratic mathematical models for predicting cutting force and surface roughness under dry cutting and MQL conditions were established. The analysis of the roughness and the cutting force showed the outstanding effectiveness of MQL when compared with dry cutting.

This paper presents development of a measurement and classification system for robot arm using machine vision under controlled lighting environment. The proposed system uses a single camera as a sensor for measuring and classifying objects which are bolts and nuts. Using image processing and analysis, characteristics of objects was extracted and area of blob in binary image also was calculated for classification process. For coordinate calibration process, the quadratic transformation and regression analysis were used to determine relationship between image coordinate and the world coordinate. Experiment results showed that the proposed system can measure and classify the components exactly of 100% from all samples tested and measurement errors are suitable with the system which applied to a robot arm.

A machine vision system for the automatic classification process is developed under different lighting environments, and has been applied to the operation of a robot arm with 6 degrees of freedom (DOF). In order to obtain accurate positioning information, the overall image is captured by a CMOS camera which is mounted above the working platform. The effects of back-lighting and front-lighting environments to the proposed system were investigated. With the front-lighting environment, four different conditions were performed. For each condition, global and local contrast threshold operations were used to obtain good image quality. In this study, a quadratic transformation used to describe the relationship between the image coordinates and the world coordinates was proposed, which has been compared to linear transformation as well as the camera calibration model in MATLAB tool. Experimental results show that in a back-lighting environment, the image quality is improved, such that the positions of the centers of objects are more accurate than in a front-lighting environment. According to the calibration results, the quadratic transformation is more accurate than other methods. By calculating the calibration deviation using the quadratic transformation, the maximum positive deviation is 0.48 mm and 0.38 mm in the X and Y directions, respectively. The maximum negative deviation is − 0.34 mm and − 0.43 mm in X and Y directions, respectively. The proposed system is effective, robust, and can be valuable to industry, as it offers an automated robotic system with an improved flexibility for separating dissimilar items of nominal value, in order to reclaim material investments, and decrease the expense of purchasing the same items again.

With the advance of technology, aluminum alloy has been widely used in industry. In this study, the formability and spring back phenomena of thick aluminum alloy sheet metal were investigated. Deform-3D and Simufact.forming software were used to simulate the sheet-bulk forming. To find the optimal element size, the convergence analysis method for mesh of simulation process was utilized. In addition, thickness distribution and spring back phenomena of the rectangular blank with round feature of corners were also evaluated. Simulation results were compared to scanning file that obtained via ATOS based on spring back phenomena from experiments. Study results show that the optimal element size is 2 mm. The cross section that is near binder area in x-direction and near quarter area of laptop keyboard in y-direction has minimum spring back. Solid-shell element is better than tetrahedral element for analyzing sheet bulk metal forming process.

Hand-tool is one of the important products which are widely used in manufacturing industry as well as in human life. The torx is one kind of hand-tools which is considered as a case study in this research. There are two trial preforms designed to analyze their influence on forgings formability. Firstly, DEFORM-3D software was used to simulate and analyze forming processes of different preform shapes for observing the formability of each trial preform and defects during the forming processes. Die stress analysis was also conducted to investigate the die stress of the forming stages in different forming processes. Secondly, according to the formability and the die stress, the most suitable forming processes and preform were selected for actual experiments. Finally, to verify the simulation results accuracy, the feature matching and hardness test were performed. The result of this research show that appropriate forming processes and preform applied improve the quality of product compared to original product.

The magnetic particle inspection method is to detect the surface of the ferromagnetic material and the subsurface flaw. It can be considered as a combination of two nondestructive inspection methods which are magnetic flux leakage inspection and visual inspection. The visual inspection is performed by the quality control personnel under high-power ultraviolet light. Because of the strong ultraviolet light, this method has caused damage to the eyes of quality control personnel, and the detection results are prone to errors and cause missed inspections. Therefore, this study developed an automated detection system that can be used to replace manual visual inspection. This study uses a self-made aluminum alloy semi-circular tube type cover, diffused light source, high-resolution CMOS industrial cameras and image processing algorithms. The intensity of the ultraviolet light source used in this study was derived from the illumination of the semi-circular tube type light source cover. The best UV light source parameters were available when the bilateral light source was fully open, the light source illumination angle was at 120°, the light source intensity was at level 2, and the filter was used. The average value of the RGB values and the standard deviation of defects on work-piece were analyzed. Experimental results showed that the RGB average values were 38.66, 35.99, and 26.06, respectively, and the maximum standard deviation was G standard deviation of 86.83.

In this research, the performance of orthodontic self-drilling correction screw of Titanium alloy (Ti6Al4V) and stainless steel (Stainless 316L) was analyzed by using the finite element method. SolidWorks software was employed to design the 3D models. The dimensions and geometrical parameters of the mini-screw according to ASTM F543-07. The analysis was conducted by using Ansys software. The biomechanical test is carried out that includes the static bending test and the torsion test. Based on the analysis of the results of the tests, the initial stability of the stainless steel screw is slightly higher than the titanium alloy screw. However, in prolonged stress results, attention to interactions with biological organisms from the medical perspective, the titanium bone screw have more advantages. In terms of the maximum load, the titanium alloy screws are better than the stainless steel screws. In terms of stiffness, the stainless steel screws proved superior to the type of titanium alloy. The orthodontic self-drilling correction screw saving of about 30% of the torque and more stable compared to the nonself-drilling type.

Porthole die extrusion has a great advantage in the forming of hollow section of aluminum alloy tube. The proposed paper aims at the development of an extruding seam square tube of AA7075 high strength aluminum alloy by simulation and experiment. There are several factors related to extrusion load such as: billet temperature, billet dimensional, flow stress, die cavity and product geometry. The extrusion loads and die stresses for a hot extruding square tube of AA7075 with respect to different product have been investigated. This study used DEFORM 3D software based on finite element analysis to simulate two different types of hollow extruding die configurations in the square tube extrusion process, namely: Type I welding position at the corners of the square tube and Type II on the side faces. The welding strengths of these two kinds of extruded tube are studied by expanding test and tensile test. The die life of these two extrusion die components are studied based on the die stress and die wear information. The results of FE analysis are compared with those experiments.

This paper describes the establishment of a machine vision system for measurement compression spring. This kind of spring is used in the automotive suspension systems on cars. The special features for this kind spring are non-uniform diameter, non-regular helix and non-unique center line. A reverse engineering to construct spring geometry for further manufacturing becomes necessary when there is no CAD data for this spring. The reverse measurement facilities include contact stylus instrument, laser scanner and white-light grating system. These devices can be used to measure spring, but time and money consuming is a common problem with this measurement solution. In this paper, a new method with low-cost measurement developed to solve this problem. A man-machine interface for measurement by Visual Basic 6.0 has been developed which adopted a single camera mounted in a three-axis measurement frame. A fixed focal length camera and image processing technique were used to construct the object's position as well as coordinates. Therefore, the spiral of the measured spring can be constructed. By comparing the measured data to the ATOS system with Poly-works, the differences can be obtained. The largest upper deviation is about 3.3 mm and the largest lower deviation about −2.7 mm for spring geometry construction.

A method for fabricating a microlens array composite optical film by a seamless roller mold of self-assembly is presented. The roller with a lot of random cavities is used to produce a polyethylene terephthalate (PET) composite optical film with 3D random microlens arrays using the ultraviolet (UV) roll-to-roll printing. The luminance gain and haze are 1.247 and 86 %, respectively, giving the PET composite optical film the properties of a brightness enhancement film and a diffuser. Solid glass beads (SBs) are used for parameter testing for self-assembly. Then, 3 M glass bubble beads (BBs) are used to fabricate a seamless roller mold. The optimal parameters of the self-assembly process for the SB are a coating speed of 135 mm/h with a 39 % volume ratio, and those for the BB are a coating speed of 30 mm/h with a 3 % volume ratio. Finally, the PET optical film is used in the green energy lighting testing of a commercial bicycle light-emitting diode (LED). The results show increased lighting angle and light uniformity, making it similar to traditional tungsten light.

Die-casting process is significantly used in the industry for its high productivity and less post-machining requirement. For high pressure die-casting, it needs well-design of gating and runner system; therefore, die cavity design and technology parameter calculations are essential. In the current paper of die-casting for automobile starter motor casing, the following issues are focused: filling simulation, defect analysis, and finally the use of the Taguchi multi-quality analysis method to find the optimal parameters and factors to increase the aluminum ADC10 die-casting quality and efficiency. When the casting speed is increased, the volume shortage detects due to solidification procedure can be reduced. However, if the casting speed exceeds a permissible level, the defects of gas volume and porosity will occur. After Taguchi method analysis, the results of the optimum parameters are: for the gate area of 40mm2, group 2 of the gate location, the speed of the liquid metal at the gate 50 m/s, the temperature of molten aluminum 670° C.

This study investigates bonding and shear flow phenomena for nanoscale BGA (Ball Grid Array) solder joint in electronic package pads with or without intermetallic compounds (IMC). Three types of solder joints have been studied, such as Sn100%, Sn44%-Cu56% and Sn92.5%-Ag3.5%-Cu4%. The IMC layer composes of Cu6Sn5 and Cu3Sn materials. The above materials are arranged according to the single crystal structure. The molecular dynamics method and the embedded atom potential are used to understand the internal micro structure, interface layer and the bonding strength differences for welded joints. The total energy of the simulated system includes the molecular potential energy, kinetic energy and electromagnetic coupling moments. An aging process at 453K for solder joint without IMC layer has been conducted to understand the aging effect.

The proposed paper aims at the development of extruding seam square tube of AA7075 high strength aluminum alloy by simulation and experiment. There are several factors related to extrusion load such as billet temperature, billet dimension, flow stress, die cavity and product geometry. The extrusion loads and die stresses for hot extruding square tube with respect to different product have been investigated. Since AA7075 behaves high forming resistance comparing to AA6063 and AA6061, the product design and die design should be modified in order to meet with the limitation of extrusion machinery. Moreover, AA7075 has high thermal welding crack behavior by comparing to AA7003. Therefore, In order to provide high contact pressure enough to conduct solid welding for the split AA7075 materials in welding chamber, the specific die cavity design has been finished. Then, the solid welding pressure can be increased. The research results show that under the same forming conditions such as fixed ram speed and billet temperature, the extrusion force for the product with thick thickness is small than the one with thin thickness. The same result was obtained for die stress. A square tube extrusion experiment has been conducted by installing die set into forward extrusion machinery. The experiment and simulation results have been compared and discussed.

Nanoimprint lithography (NIL) was used to create a film with photonic crystal structures in the organic light-emitting diode (OLED) component. By utilizing various stamps, such as with photonic crystal structures and with grating structures in polymethylmethacrylate (PMMA) were studied. The better formability belongs to a stamp of photonic crystal patterns and molecular weight of PMMA in 350K and 996+15K in double layers. A photonic crystal with nanostructures in a period of 400nm was fabricated as a photonic crystal film and was integrated into an organic light emitting diode (OLED). The experiments show that the OLED without photonic crystal films behaves 2.11cd/m^2 for luminous intensity, 2.336cd/A for lightening efficiency (@h"L), and 0.475lm/W for lightening power (@h"P), under the driving voltage of 10V and current of 0.009012A; the OLED with the photonic crystal films behaves 250cd/m^2 for luminous intensity and 2.774cd/A for @h"L, and 0.871lm/W for @h"P, under the same driving voltage and same current, which shows that the latter performs well.

According to MD simulation results, pressing depth between two bonding materials will affect bonding strength. Alloy material (Al0.9Cu0.1) had void defect phenomenon in low bonding speed condition because the increasing chance of atom migration which will result in low bonding strength. High tensile speed causes material fracture phenomena happen earlier than low speed. Material stress in low speed is smaller than in high speed. Fracture morphology of material is different in different tensile speed. In low speed condition, material can be stretched thinner than in high speed condition. Material in high temperature has greater kinetic energy than low temperature; therefore, material in high temperature has better formability and behaves larger tensile strain than low temperature. For pure aluminum, when temperature raises to 900K which is close to melting point (933K), its crystal structure is no longer belongs to F.C.C. structure, so bonding strength is weaker than low temperature. Large size material has larger contact area than small size material; therefore, the tensile force and tensile strength of the former are larger than the latter. The order of bonding strength for these three materials is: binary alloy > pure copper > pure aluminum.

Large size TFT-LCD (Thin-Film Transistor Liquid-Crystal Display, which is commonly called as panel) is made after lots of processes and is cut based on the required size in the last process. Deckle-edge (Burr) and other defects were produced by cutting. Therefore, it needs to examine the products’ defects before grinding the edges or the following processes. This research developed a new type and high-efficiency apparatus for panel-edge inspection. The defects are sorted based on three types “Fractures, Cracks and Dark-spots” by using image-subtraction, binary thresholding, and blob-analysis methods. The proposed system can improve the efficiency on panel-edge inspection for panel manufacturers. The production of flat panel-edge inspection can be increased to over 40% which can resolve the bottleneck processes for panel industry.

Along with social progress, people pay attention to health. Modern people choose the gym to maintain posture and body functions well, therefore, the gym popularize everywhere. Popularity of expensive fitness equipment to bring a lot of convenience, but different users share of fitness equipment have different condition, often caused damage by use, which is the most important factor for the material fatigue damage. This study chose the exercise bike parts “self run bushing” to create a fatigue life assessment mechanism. In this study, to the fatigue analysis was conducted, by using finite element analysis according to the material S-N curve and Miner cumulative damage theory in a series of cyclic loading. To analyze fatigue life, analytical and experimental studies through mutual verification were conducted which can obtain the expectation life period of the self run bushing. The load spectrum based on different user can also be considered in this study. Based on the design frequency from different users, after the study of distribution of reliability and failure, the most appropriate time-out and the best replacement time can be obtained.

Direct extrusion by porthole – bridge die configuration has been successfully used to fabricate products with hollow cross sections for 6000 series aluminum alloys. However, if for 7000 series aluminum alloys, this situation alerts since different alloy composition such as Cu causing hollow extrusion failed due to not enough welding strength in seam. In order to determine the solid welding conditions during hollow extrusion with porthole die structure for high strength aluminum alloy, an easy tooling configuration has been designed. The proposed method is easy and cheap because there is no necessary to conduct experiment in controlled environment such as in vacuum chamber of Gleeble test or in a protective atmosphere. A seam and hollow extrusion for square tube has been conducted to obtain the welding strength comparison to the proposed solid welding method which shows good agreement.

Image-processing technology is widely used in industry for automatic inspection and measurement through the capturing of object images by CCD (Charge-Couple Device) cameras and the built-in algorithms. VR (Virtual Reality) is a high-end user interface that involves real-time simulation and interactions through multiple sensorial channels. Three important characteristics of VR are: immersion, interaction, and imagination which enable the users more direct and useful communications with manufacturing prototyping systems. In this paper, an image processing system was developed for measuring small parts such as 3C rivets automatically. If using optical sensors to measure such small parts, the mechanism is complicate. However, if using image process technology, the mechanism is simple and the measurement is efficient. All we have to do are to develop measuring algorithms as well as computer programs. A VR-based image processing system was also developed by importing 3D CAD objects and applying the relationships between these objects. Therefore, the image processing algorithms as well as the layout of the measurement system can be tested by using the proposed VR system without any real machine such as transfer mechanism, CCD camera, and computer with image processing program.

The effects of extrusion temperature, extrusion ratio, and workpiece size on the extrusion process of NbTi alloy nanowires (workpieces) are studied using the modified embedded atom method potential. The results are discussed in terms of atomic trajectories, potential energy, extrusion force, and stress. Simulation results show that the workpiece atoms near the ram lose their structural order when the extrusion process begins. The number of disordered atoms gradually increases with increasing ram displacement in order to relax the increasing pressure from the ram. The extrusion force and potential energy increase with increasing temperature. The effect of extrusion ratio dominates the extrusion force once the workpiece atoms start entering the mold opening. A large extrusion force is required for large workpieces with a small extrusion ratio; however, a small workpiece with a large extrusion ratio could lead to high peaks and a large oscillation in the force curve.

As a successful solution applied to hard machining, the minimum quantity lubricant (MQL) has already been established as an alternative to flood coolant processing. The optimization of MQL parameters and cutting parameters under MQL condition are essential and pressing. The study was divided into two parts. In the first part of this study, the Taguchi method was applied to find the optimal values of MQL condition in the hard milling of AISI H13 with consideration of reduced surface roughness. The L9 orthogonal array, the signal-to-noise (S/N) ratio and analysis of variance (ANOVA) were employed to analyze the effect of the performance characteristics of MQL parameters (i.e., cutting fluid type, pressure, and fluid flow) on good surface finish. In the results section, lubricant and pressure of MQL condition are determined to be the most influential factors which give a statistically significant effect on machined surfaces. A verifiable experiment was conducted to demonstrate the reliability of the results. In the second section, the optimized MQL parameters were applied in a series of experiments to find out cutting parameters of hard milling. The Taguchi method was also used to optimize the cutting parameters in order to obtain the best surface roughness. The design of the experiment (DOE) was implemented by using the L27 orthogonal array. Based on an analysis of the signal-to-noise response and ANOVA, the optimal values of cutting parameters (i.e., cutting speed, feed rate, depth-of-cut and hardness of workpiece) were introduced. The results of the present work indicate feed rate is the factor having the most effect on surface roughness.

Due to the rapid progress of industrial development, the formation of lightweight and small-size parts is becoming increasingly important. Especially in the IC and 3C industry, the sheet metal forming of miniature parts is especially interesting. Size effects such as specimen dimension, blank thickness, punch corner dimension, grain size, and grid dimension (for strain measurement), as well as the microstructure of material and surface condition all seriously influence the forming of miniature parts. In this paper, systematic experiments including Erichsen stretch forming and hydraulic bulge, and strain analyzers including for circular and rectangular grids are described for establishing the relationships of sheet metal formability to process parameters. The details of the experimental procedures and results are presented and discussed.

A molecular dynamics analysis scheme is proposed to study nanoimprint processes by considering the following effects: temperature, punch velocity, spring back, etc. The nanoimprint process being studied in the proposed paper is similar to nanoimprint lithography, except that the material under investigation is metal. The nanoimprint process being simulated in the proposed paper is comprised of one punch and one specimen. By varying the environment temperature and the punch velocity, useful information has been obtained. If the environment temperature is higher, then the needed punching force becomes smaller. When increasing punch velocity, the needed punching force also increases. The internal energy of specimen under high temperature is smaller than that of low temperature. When increasing punch velocity, due to shorter relaxation time in the specimen, the absorbed energy will increase rapidly, and finally if it reaches the marginal value the specimen collapses. The spring back effect is an important factor to discuss. Since the imprinting energy is absorbed mainly by those atoms close to the punch, especially at both sides of punch, if as the punch leaves the specimen, the spring back phenomena of deformed-atomic structures in horizontal direction are more serious than in vertical direction.

A molecular dynamics analysis model is proposed to study the effects of parameters on the nanoimprint process, for example, taper angle, imprint depth and spring back. The nanoimprint process comprises one punch and one specimen at an isothermal state of 400 K, while the deformed material is a copper fcc single crystal and the punch material is a nickel fcc single crystal. There were a total of 10,080 atoms in copper measuring 12.02 nm and 5.72 nm in length and height, respectively. There were a total of 4,200 atoms in nickel with a typical length and depth in a punch tooth of 6.24 nm and 3.52 nm, respectively. Computer simulation codes based on Hamiltonian dynamics, periodical boundary conditions and the Morse potential function were used to simulate the nanoimprint process. By varying the punch taper angle and the imprint depth, useful information about the nanoimprint process was obtained.

Hydroforming is one kind of plasticity working, which can be used to increase the diameter, to change the geometry, or to expand the outer walls of cylindrical shells or tubes. The forming principle of hydroforming is by using a die to constrain the outer geometry of a tube and then pumping high pressure oil into the inner tube, so as to force part of the tube to flow into the die cavity. In order to prevent local thinning and to improve material flow capability, an axial force may be imposed on the both sides of the tube. If the axial force is not imposed correctly, a buckling defect will occur. The forming theory and plasticity of the hydrostatic bulging process are studied. The parameter effects on the hydrostatic bulging process will be analyzed by using a DEFORM-3D finite element analysis package. A new approach to measure 3D deformations and plastic strains in forming parts is also presented. A strain analysis module is also built based on the geometry of deformed grids and initial grids. The principal stretch ratios and angle changes of grid patterns are calculated, and the logarithmic strains are also computed.