In this study, we newly developed cutting tools having a micro stripe texture on their flank face using femtosecond laser technology to improve the flank wear resistance. Face milling experiments on medium carbon steel showed that the developed tool significantly reduced the flank wear compared to the conventional tool, and the tribological behavior of the textured flank face were discussed by evaluating cutting forces. Moreover, the relationship between the flank wear resistance and texture dimensions was investigated.

View full abstract

This paper presents the result of an experimental study about low-pressure jet coolant, with the primary focus on the influence of the flow speed and the flow rate upon the tool life in cutting stainless steel. Low-pressure jet coolant is generally preferable to flood coolant from the aspect of the tool life, because the former can attain higher jet speeds even at lower flow rates, owing to the fact that the nozzle can be installed in the close vicinity of the tool tip. In the experiments of the present study, type 304 stainless steel was turned with low pressured jet coolant, in view of extending the tool life of coated carbide inserts, with two different nozzles at two different cutting speeds. It was transpired that the low-pressure coolant method exhibits nearly the same ability as the air jet assisted machining method in extending the tool life. The results indicate that, unlike the air jet assisted machining method, the flow rate plays a crucial role as well as the flow speed in the low-pressure jet coolant method.

View full abstract

Small lot machining for elastomer has been attracting much attention to support efficient product development. Elastomer endmilling is expected as a promising approach to achieve the problem. In this research, in-process observation of elastomer endmilling is investigated to quantify instantaneous workpiece deformations. Measured deformations with straight flute endmill are compared with machining error to investigate an error generation mechanism. From the experimental results, it has become clear there are different error generation mechanisms between up cut milling and down cut milling. Instantaneous workpiece deformations show a clear correlation only in up cut milling.

View full abstract

As integrated circuits continue to be miniaturized, the penetration holes of bonding jigs have also become smaller. However, micro-drills have a tendency to break drilling small holes with high aspect ratios. Moreover, to reduce the impact on the environment, there has been a recent trend towards the use of lead-free brass as jig materials, and these are very difficult to drill. In the present research, small holes were drilled in lead-free brass using a micro-drill, and the influence of web thinning, the helix angle and the nick geometry on chip evacuation was investigated. The results indicated that a drill with a helix angle of 15° exhibited a long tool life. The formation of a nick on the cutting edge was found to be effective in decreasing the thrust force during deep drilling. A drill with a relatively shallow nick perpendicular to the cutting edge had excellent chip discharge performance, and its cutting force was stable. Nick treatment is effective in decrease of a thrust force at a deep drilling position.

View full abstract

As a fundamental study for developing a self-sharpening tool in CFRP machining, an orthogonal cutting test was carried out using a CFRP plate and a cutting tool made of high-speed steel. Through the cutting test, time changes in cutting loads and tool wear volumes were measured. As a result, it was found that the orientation direction of carbon fibers and the flank angle of the cutting tool are important factors to extend the tool life in CFRP cutting.

View full abstract

In order to prevent depth-of-cut notch wear of a cBN tool in Inconel718 cutting, BUE extrusion behavior was focused. Turning tests were conducted to make a comparison between commercial and well-designed tools. The life time of the well-designed tool for stable BUE extrusion is roughly twice longer than that of the commercial tool. The tool with positive rake angle is effective to be stable BUE extrusion. As the results of the turning test considering rake angle, the notch wear hardly appears on the well-designed tool at 1200 m cutting length while the commercial tool fractures in a macro scale less than 1000 m.

View full abstract

The demand of CFRP (Carbon Fiber Reinforced Plastics) has been become heavy for its light weight and high strength. However it is a problem that the machining cost becomes high because the tool life is very short. The objective of this research is to clarify the tool wear mechanism on the milling of CFRP. Therefore the influence upon tool wear by the fiber orientation of CFRP was focused on. Then tool wear and cutting force were measured during the milling of the CFRP which has the unidirectional fiber orientation. As a result of the experiment, the relationship between tool wear and fiber orientation of CFRP was made clear. When feed rate was 500 mm/min, for example, tool wear increased because number of cut fibers increased when angle between feed direction and fiber orientation was about 45 degrees. On the other hand, tool wear was reduced by low number of cut fibers when the angle was about 0 degrees. In addition, tool wear model that based on the experiment was proposed. Number of cut fibers and fiber cutting angle varied according to fiber orientation were considered in the model. Then the model was validated comparing with the experiment.

View full abstract

CFRP (carbon fiber reinforced plastic) is a composite material having strong anisotropy. The direction of carbon fibers influences tool life, surface integrity, and machining accuracy. In this study, the experiments based on side milling tests are carried out by changing the carbon fiber direction and the coolant (dry/wet/LN_2). The effects of these changing factors on the cutting force, surface integrity, and tool wear are examined. As a result, the machining accuracy is found to be affected by the radial depth of cut and the direction of the carbon fibers. The use of cryogenic machining improves the surface integrity.

View full abstract

In this paper describes the optimal shape of cutting edge on the ball-nose end mill for cutting technique of CFRP composite plates without burrs and delaminations. The shape of a ball-nose end mill is evaluated as one of the useful cutting tools for CFRP drilling by our experiments. The connection point which is between outer peripheral side flute edges and bottom blade on the ball-nose end mill is remarkably affected to finished surface and accuracy of diameter on the drilled holes. The cutting edge around connection point of tip and side cutting edge lift the top layer of CFRP as burrs and delaminations.

View full abstract

This paper reports about the stress field inside of the workpiece under ultrasonically assisted orthogonal cutting(UAC) condition. UAC improves processing accuracy by reducing average cutting force. However general dynamometers have an insufficient frequency band to measure processing phenomena in ultrasonic vibration band. Stress field inside of the workpiece during UAC was observed by combining method consists of the pulse emitting source synchronized with ultrasonically vibrating cutting edge and the photoelastic method. Instantaneous stress field also was observed during UAC. It was found that UAC reduced the stress field in comparison with conventional cutting (CC).

View full abstract

Vibration at an ultrasonic frequency is superimposed on the motion of the cutting tool used in conventional machine tool in ultrasonic-vibration assisted turning. Ultrasonic assisted turning (UAT) combines precision machining with small-amplitude tool vibration to improve the fabrication process. It has been applied in the turning machine for more precise in machining process. In this paper, theoretical modelling and instrumental implementation issues for ultrasonic assisted turning are presented and explored in depth. The modelling is focused on establishing the scientific relationship between the process variables/tooling geometry and all the process outcomes including tool wear, surface roughness, cutting force and surface integrity. Instrumental implementation mainly includes the design of the ultrasonic generation device and its control system. The design of the vibration assisted machining device is based on combining a piezo actuator into a turning tool holder (VAT Tool Holder). The control system is developed using LabVIEW programming. Frequency and amplitude of the vibrations can also be controlled by using this LabVIEW programming system together with the interfacing between the computer and the Data Acquisition (DAQ) card. For the Finite Element Modelling (FEM), Ansys Software will be use analyse the Modal and Static Analysis. This paper also concludes with a further discussion on the potential and applications of the techniques and systems developed for the usage of turning machining in manufacturing purposes.

View full abstract

Free abrasive machining has been widely used for the finishing of mono-crystallined sapphire wafers. There are, however, critical issues remaining, such as degradation of flatness due to the nature of pressure controlled in-feed dynamics, environmental load due to disposal of wasted slurry, and time/cost consuming. Fixed abrasive machining is one of the potential alternatives to make a breakthrough to such problems. This study aims to development of fixed diamond abrasive pellet for final finishing of mono-crystallined sapphire wafers.

View full abstract

The tracking interferometer is a laser interferometer with a steering mechanism to change the laser beam direction to follow a retroreflector ('target') attached to the machine spindle. Based on the multilateration principle, it measures the target's three-dimensional position at an arbitrary location in the workspace. This paper proposes the 'open-loop' tracking interferometer, where the laser beam is regulated toward the command target position. This eliminates the automated tracking mechanism and thus may significantly reduce the manufacturing cost of conventional tracking interferometers. The paper investigates its measurement uncertainty both analytically and experimentally.

View full abstract

This paper describes estimation and evaluation of volumetric errors of machine tools based on the multi-lateration principle. The principle of multi-lateration is to determine the target location by measurement of distances from three points. The measuring method in this paper is for quicker, low-cost evaluation of volumetric errors by using only a laser interferometer. We evaluate its estimation accuracy by experiments and simulation. To simplify the problem, this paper focuses on the two-dimensional measurement of the target position.

View full abstract

On-machine measurement using a laser displacement sensor, with rotating a workpiece on a 5-axis machine tool, has a strong advantage in its measurement efficiency. In such measurement, miscalibrations of a laser displacement sensor' position and direction, as well as motion errors of the machine's rotary axes, are clearly major contributors for the measurement uncertainty. This paper first formulates the influence of miscalibration of the sensor's installation on the measurement uncertainty. Then, based on the present formulation, a method to identify location errors of rotary axes, by using the present on-machine laser measurement system, is proposed.

View full abstract

Measurement devices are proposed for the relative thermal displacement between the grinding wheel and the workpiece, and for the thermal displacement of the wheel spindle itself during rotation of the wheel spindle. Then by separating the thermal deformation of the wheel spindle and the wheel spindle head from the relative thermal deformation between the wheel spindle and workpiece, the thermal deformation of the grinding machine is evaluated in detail. The following results are obtained. (1) The grinding wheel spindle and the wheel spindle head cause the thermal displacement in various directions. (2) A percentage of the influence of the wheel spindle and the wheel spindle head in the relative thermal deformation is different depending upon the direction of the thermal displacement.

View full abstract

To understand the material removal mechanism in MCF polishing process, distributions of pressure and shear stress in polishing zone during MCF polishing are investigated. Larger pressure occurs at the position which is closer to the center of MCF slurry, and the maximum shear stress appears at the position of about 5 mm from MCF slurry center. MCF carrier rotation speed and working gap have strong correlations with the material removal rate (MRR) while magnet revolution speed shows a little effect on MRR. Shear stress shows more influence on MRR than pressure. A MRR model including both shear stress and pressure is proposed.

View full abstract

In the telescopic interferometer KAGRA (Large-scale Cryogenic Gravitational wave Telescope), the mirror made of sapphire (α-alumina) is required. The focal length of mirror is 7 km and it must be finished by polishing after grinding. In order to polish the mirror precisely, polishing characteristics of the sapphire must be researched. In this study, the polishing characteristics are examined and the dependence of the crystal orientation on the polishing rates is researched. In the experiment, sapphire wafer is polished by using rotational small tool and SiO_2 abrasive.

View full abstract

Recently, needs for high-precision large aspheric glass lenses are increasing. The chromatic aberration is caused by changing the refractive index by the wavelength of light. In order to remove the chromatic aberration, it is effective to counteract the change of refractive index by combining the convex lens and concave lens. In this study, magnetic field-assisted polishing setup using a permanent magnet is proposed and developed for the uniform polishing of the concave large aspheric glass lenses. In this experiment, the ground concave aspheric glass lenses were polished uniformly and the changes of the aspheric form and surface roughness were evaluated. The experimental results show that very smooth surfaces of 10 nm Rz were obtained by 90-minute polishing. It was clarified that the proposed uniform polishing methods are useful for the finishing of large concave aspheric glass lenses.

View full abstract

In this study, the fundamental polishing characteristic of fixed abrasive polishing by using alumina abrasive grain for single crystal Si was investigated. Pyramidal structured polishing pad including alumina abrasives was used and KOH aqueous solution was used as polishing fluid. As a result, it has been clarified that an optimum concentration of KOH aqueous solution to create a smooth surface has been about 5wt%. In this condition, finished surface roughness has been about 80nmRz. Furthermore, they have been shown that cutting edge has worn hardly and polishing performance has kept in long time polishing without dressing.

View full abstract

This paper describes a new method in increasing discharge energy by changing the duration of high frequency discharge. In this method, a train of high frequency pulses are supplied within a pre-determined duration after discharge ignition is detected. The high frequency discharge can continue during the pulse train, thus enlarging the crater size. The results show that when the pulse train duration is increased, higher number of discharges per pulse train can be obtained and size of discharge crater can be enlarged. At higher frequencies, the probability of obtaining continuous discharge was higher because interval between individual pulse discharges was short. Higher material removal rate can be obtained when longer pulse train duration is used.

View full abstract

This paper describes micro electrochemical machining (ECM) of curved patterns using shaped electrolyte jet. In electrolyte jet machining (EJM), the workpiece is machined locally in the area hit by the jet. To fabricate a curved groove without translating a cylindrical jet, a novel slit nozzle with curvature was developed. The machining characteristics of the curved slit nozzle were investigated experimentally, and it was found that curved grooves similar to the cross section of the jet can be machined. The electric potential distribution in the electrolyte flow and the current density distribution over the workpiece surface were calculated and compared with those of a cylindrical nozzle.

View full abstract

In this research, discharge duration and pulse frequency were studied to determine the optimum conditions for creating a single crater. In addition, the relationships between pulse frequency and the surface characteristics of a whirling electrical discharge texturing (WEDT) processed were determined. It was confirmed that the texture-area ratio and the total removal volume of craters, but not crater diameter or crater depth, can be controlled by adjusting pulse frequency. Moreover, after honing, surface characteristics decreased owing to the removal of protrusions. With honing, the surface roughness of the textured surface expectedly led to a reduced friction coefficient.

View full abstract

In this paper, the authors describe a highly efficient deburring method using whirling electrical discharge machining (whirling EDM) with a wire tool electrode. The back-surface deburring of a small hole or a cross-drilled hole is difficult. Thus, whirling EDM method with a wire tool electrode, which requires no changes of the tool electrode after deburring, was developed. The authors clarified the processing features of whirling EDM and dry whirling EDM with a wire tool electrode through fundamental experiments on the back-surface chamfering of small holes. They also verified that it is possible to remove back-surface burrs of a small hole by dry whirling EDM.

View full abstract

In large-area EB irradiation method, the convex corner tips of workpiece could be rounded with preferential material removal at the tip, which would deteriorate the shape accuracy. The shape changes of convex corner were experimentally investigated by SEM observation of the cross sections. Also, unsteady heat conduction analysis at the convex corner was done with considering the EB concentration at the tip and the electron penetration effect into the surface. The shape change estimated by the simulation of temperature distribution at the corner agreed well with the experimental one, which enable precise prediction of shape change by large-area EB irradiation.

View full abstract

In this study, the movements of tungsten wire electrode during fine wire EDM were investigated by the direct observation using high-speed camera. The results showed that the vibration amplitude and frequency depended mainly on the wire tension, and the amplitude in the direction parallel to the machining direction was a little larger than that in the perpendicular one. Also, the backward deflection of wire could be confirmed even in fine wire EDM. Furthermore, the wire vibration mode was analyzed, and it could be varied with the machining position of the thin workpiece, which possibly led to smaller wire amplitude.

View full abstract

To machine complicatedly-shaped holes is required for building pipe lines of pneumatic components or hydraulic equipments. However, the degree of freedom of machinable hole shapes is limited, since holes are usually fabricated by drilling. In order to improve the degree of freedom of the shapes, the authors devised the method to fabricate a hole on the inside wall of a hole by means of electrical discharge machining. The method employs a very simple device. The results obtained from the fundamental experiments show that the method has the possibility to machine such a hole.

View full abstract

This paper proposes a method of improving the sensitivity of the angle sensor for angular motion errors of precision linear stages. The sensitivity of the angle sensor based on laser autocollimation depends on the diameter of the incident beam on the objective lens. The relationship between the sensitivity of the sensor and the beam diameter is investigated by expanding the diameter and using a single-cell photodiode as the position-sensing detector corresponding to a small light spot. From the experimental result, the sensitivity is improved by expanding the diameter and the sensor can detect angular motion of about 0.001".

View full abstract

A surface encoder, which can measure the XYZ-directional displacements, has been developed. The XY-directional measurement range depends on the size of the XY-axis scale grating. A mosaic XY-axis scale grating, which consists of multiple XY-axis grating, has been proposed to expand the XY-directional measurement range of the three-axis surface encoder. And multi-probe surface encoder, which has two-probe, for the mosaic scale grating has been proposed. In this paper, an optical sensor head, which has four-probe for the mosaic XY-axis scale grating, was developed and basic experiment was carried out to confirm the feasibility of the proposed method.

View full abstract

This paper describes a method for evaluating damping capacity of a linear rolling bearing against bending moments. The column for generating bending moments is fixed to a carriage of a linear rolling bearing. The free end of the column is excited by a shaker. The frequency response function is calculated by an FFT analyzer based on the excitation force and response acceleration. The dynamic characteristics of a linear rolling bearing are evaluated as the modal stiffness and modal damping ratio. As a result, the stiffness and damping capacity changes depending on the direction and amplitude of the excitation force.

View full abstract

A six-degree-of-freedom (six-DOF) optical sensor has been developed for the precision positioning of a surface motor stage. The sensor consists of a two-dimensional (2D) planar grating and a reading head. This sensor has been designed in such a way that three-axis translational motions and three-axis angular rotations of the stage can be measured simultaneously through sharing a same laser source and a same measurement point on the scale grating. To improve the accuracies of the multi-DOF (MDOF) measurement system, crosstalk errors were investigated and described, and the methods to reduce the errors were proposed in this paper.

View full abstract

A long-stroke scanning electrostatic force probe (SEFP) is presented in this paper. The long range electrostatic force keeps large probe-to-sample distance when SEFP scans the profile. The probe is driven by an ultra-high precision Z scanner, which has a long effective measurement range of 50 μm with non-linearity error less than 10 nm as well as least significant bit resolution of 0.5 nm. The profile of a prism sheet with large amplitude of 25 μm is measured by the SEFP. The experiment result is analyzed and the effectiveness of the proposed SEFP for profile measurement of large amplitude micro-structured surface is demonstrated.

View full abstract

A strain-gauge-type precision displacement sensor, which is developed for positioning of a micro-XY stage, is described in this paper. The designed patterns of Cr-N strain gauges are directly sputtered on zirconia plates, which would be used as leaf springs in the micro-XY stage, by using photolithography processes to form a Wheatstone bridge circuit. The patterns of the strain gauges on the leaf spring are optimized to be sensitive area so that the displacement of the stage can be measured with a higher sensitivity. The experimental results confirmed that the designed sensor is applicable for sub-micrometre-scale positioning of the micro-XY stage.

View full abstract

Demands for a nanometer positioning with high resolution and long stroke have increased in a variety of industries. This paper presents a magnetic attraction force-preloaded aerostatic guideway, which can apply to high speed nanometer positioning system. In the proposed aerostatic bearing, in order to minimize eddy current loss, magnetic attraction force adds to a structure following the positioning table. From evaluation results of characteristics of the aerostatic guideway, the magnetic attraction force-preloaded is designed so as to obtain high performance. After optimizing the magnetic force preloaded, the experimental results confirm that the proposed guideway has sub-nanometer positioning capability.

View full abstract

A method of fabricating a lens array mold by electrical discharge machining (EDM) is proposed. In this process, the tips of rods are machined individually to form a specific surface, and then a number of the machined rods are arranged side-by-side to construct an electrode for EDM. The present study demonstrates the effectiveness of our proposed method for shaping lens array molds. The use of an electrode with multiple rods is effective for producing a lens array mold in a short time. Moreover, the repetition of the EDM process is found to be effective for generating a lens array mold.

View full abstract

This paper describes a possibility of physical 3D models created by rapid prototyping technology for informed consent in a medical field. For this purpose, a system for generating human body parts from DICOM (Digital Imaging and COmmunication in Medicine) data including an image data of CT (Computed Tomography) or MRI (Magnetic Resonance Imaging) to manufacture a real model with using a RP (Rapid prototyping) machine has been constructed. A feasibility of the proposed system is demonstrated by analyzing some created physical 3D model shapes and operating cost in this research.

View full abstract

A novel metal additive manufacturing system called Rafael 150V was developed that uses a 500 W quasi continuous wave (QCW) laser for sintering and a vacuum system for antioxidizing and contamination removal. The effect of the QCW laser was not considered here. The vacuum effectively prevented the built parts from oxidization and removed contamination from a powder surface, when the vacuum pressure during fabrication was less than 2x10^<-2> Pa. Samples fabricated from titanium alloy (Ti-6Al-4V) powder using this system had a density higher than 99 %, good surface condition, and a roughness (Ra) of about 15μm. The vacuum system enables the Rafael 150V system suitable for practical use.

View full abstract

Fabrication of replica nickel mold by thermal nanoimprint and development of nickel mold materials which were softened at high temperature were investigated. Ni-based CNT composite coatings were formed by ultrasonic assisted electroplating using a horn sonicator. Nickel sulfamate plating bath adding 1.6 g/L CNTs which was 9.5nm in diameter and 1.5 μm in average length was used. Vickers hardness of Ni-based CNT composite coatings was over 500 HV at room temperature and under 50HV at high temperature range from 400 to 600℃. After heat treatment at 500℃, grain size of Ni-based CNT coatings became larger than that of normal coatings. Ni-based CNT composite coatings had random crystal instead of column crystal which pure nickel coatings had. It was thought that softening of Ni-based CNT composite was based on containing CNTs and transformation of crystal structures. Replica nickel molds containing carbon nanotube with 5μm square dot pattern could be fabricated by thermal nanoimprint.

View full abstract

The tool damage in the high speed rotary machining process was evaluated to understand the mechanism of tool damage in this process. In order to reduce the model size and simulation time, a specialized numerical simulation technique was proposed by combining the non-isothermal analysis using the decoupled heat transfer analysis for tool to find out the tool temperature in the steady state. The simulation results were applied to the wear damage model proposed by Usui to find out the tendency of tool wear depth for tool damage evaluation.

View full abstract

An analytical model is applied to prediction of cutting force in drilling of carbon fiber reinforced plastics (CFRP). The orthogonal cutting tests were conducted to measure anisotropy in the uniaxial CFRP, where the cutting direction is changed with respect to the fiber orientation. The orthogonal cutting data were associated with the relative angle of the cutting direction to the fiber orientation. The thrust and torque in drilling of the unidirectional CFRP are predicted in the chip flow model with piling up the orthogonal cuttings. The periodical changes in the cutting forces are also simulated by anisotropy due to the fiber orientation.

View full abstract

In this paper, the cutting mechanism and cutting performance of a ball end mill on an inclined surface using the straight-line path method are investigated. First, a cutting model assembled by a tool and a workpiece is carried out using 3D-CAD. Next, the cross-sectional cutting area is calculated by the interference of the rake surface and the uncut chip volume. Then, the evaluation value corresponding to the cutting torque is calculated. After that, the cutting force and surface roughness are measured and the cutting torque is calculated. Finally, analytical and experimental results are discussed, and then the cutting conditions which are expected good cutting performance are considered.

View full abstract

In this paper, we examine ways to evaluate the appearance of unpainted plastic parts as a basic study for reducing environmental impact by manufacturing plastic products that do not need to be painted. We focus on burn marks, which are typical examples of the poor appearance of plastic products detected at factories. First, we take photographs of test pieces, and then we examine the characteristics of each image by using image analysis. Subsequently, we compare the results of image analysis of the various burn marks, and study the influence that the change of the degree and the area in burn marks has on the characteristic of an image.

View full abstract

The drilling of CFRP and titanium stack was carried out and the temperature at the bottom surface of a hole being drilled was measured by using an infrared radiation pyrometer with an optical fiber. The optical fiber is inserted into the oil hole of an internal coolant carbide drill. The temperature measured is considerably higher during the drilling of titanium alloy than that during the drilling of CFRP. A heavy thermal damage is observed at the CFRP-hole edge of Ti/CFRP stack. This is probably because the resin was thermally damaged by the Ti-burr which is heated to high temperature.

View full abstract

This paper defines static and dynamic component parameters based on the method that converts thrust and torque detected during drilling process into equivalent thrust force and principal force. The features of the parameters are extracted by wavelet packet transform (WPT) and then they are transferred to a back propagation neural network (BPNN) as inputs to predict the drill wear. Experiments with different drilling conditions and workpiece materials were conducted to prove the reliability of this method.

View full abstract

Although machining operation monitoring may significantly enhance manufacturing performance, industries remain hesitant to implement complex external sensor systems. We previously proposed a sensor-less method for monitoring the tool condition based on disturbance observer theory, but the applicability of this theory to tool wear monitoring has not yet been proven. The present paper advances and applies disturbance observer theory to tool wear monitoring during drilling. The experimental results showed the feasibility of determining wear-induced increases in the cutting load. Future research will involve extending the wear monitoring approach to other manufacturing processes.

View full abstract

Presently, buffing processes are manually conducted by a technical expert. Therefore, the automation of this process is desirable. To automate the buffing process, an effective process monitoring technique that supervises the buffing tool conditions in real time must be developed. The authors propose a technique that monitors the buffing tool conditions without additional sensors. The validity of the proposed method is verified through numerical simulations and experiments.

View full abstract

MQL has been proven as the best method to replace flood machining condition due to its ecological and fluid coolant benefits. From the previous research, it is found that the benefits of MQL can be fully utilized by a proper applying and understanding the mist character. The supplied coolant comes with different flow patterns such as laminar, transient and turbulent flow. The different flow pattern produces different velocity of the moving particles and the knowledge of flow pattern are not highly stressed. This study is done to determine the appropriate flow pattern of the mist in order to choose the nozzle distance from the cutting tool for the minimum quantity lubricant using Particle Image Velocimetry (PIV). Particle Image Velocimetry (PIV) can be considered as a reliable tool to measure the mist flow to obtain mist velocity and flow pattern. The nozzle distance of 5 mm from cutting edge under MQL machining, shows reduction in temperature and cutting force using higher pressure to supply cutting fluid.

View full abstract

This research work aims to reveal the cutting characteristics of a stacked silicone rubber sheet (50 Shore A) subjected to the indentation of keen tungsten-carbide (WC) blades. Cutting parameters, i.e. feed velocity and blade type were varied as experimental condition. Through the variation of these cutting parameters, it was found that they affected the cutting characteristics of the worksheet. In addition, a finite element method (FEM) analysis was carried out using a non-linear elastic Mooney material model. It was revealed that an appropriate crack propagation model is needed to simulate the silicone rubber indentation.

View full abstract

In recent years, the productivity of machine tools have been significantly improved by using computer based CAD/CAM systems for Computer Numerical Control(CNC) program generation. There are many CAM software in the market that provide tool path programming and can be applied to different types of machining. However, in most cases the efficiency of machining in CNC is still relied on the optimization of the tool path. Hence, this present paper presents a Genetic Algorithm Tool Path Optimization (GATPO) method using to obtain the shortest tool path for three axes CNC drilling machine. A user friendly Graphical User Interface (GUI) has been developed using MATLAB to input various parameters which adapts Travelling Salesman Problem(TSP) in determining the distance took during machining. Two kinds of crossover method have been applied, i.e., single-point crossover and two-point crossover to observe the effect of them. The simulation result ascertained that our proposed GA based tool path optimization is useful to find a lower distance of tool path generation for hole drilling process.

View full abstract

This paper presents the automation of soil testing using an industrial robot with six degrees of freedom. Mixing soil and cement for soil testing imposes a heavy burden on workers. For shortening the soil test time, we focused on soil and cement mixing and developed a controllable mixing system using a robot and a motor unit to monitor and carry out soil-cement mixing, respectively. Using a software program, the system alters the mixing paddle revolution, rotation, position, and posture angle. As a result, the phenomenon that occurs during soil-cement mixing is evaluated using the system and the data for developing in demand.

View full abstract