In this research, efficient fabrication process of metallic nanostructures for optical functional surfaces was aimed. Acetone chemical stamping on Au-quartz bonding strength modification was examined by peeling-off using an adhesive. Based on the results, Fabrication processes for Au nanodot array combining nanomachining and bonding strength control were proposed. Nanomachining was utilized in fabrication of a mother mold. A thermoplastic stamp was fabricated by duplicating a negative structure from the mother mold. The stamp was then used in Au stamping to form a nano line and space structure on the substrate. Thermal dewetting was finally conducted to induce the self-organization of Au film for forming a nano dot array.
Latent image is one of micro-machining techniques, it is applied to 500 Japanese yen to cope with the counterfeit techniques. The authors will anticipate latent image will be used for products such as a company logo, in which a sense of luxuriousness and glance is required. But few reports are available on latent image by machining. Therefore, simple operation CAM system for latent image has been developed. Using the CAM system, the authors challenged to create the latent image sample by machining. Then, the present study investigated whether: facilities for latent image by machining, tool and machining condition.
In this study, error characteristics of the thickness measurements are systematically investigated to obtain true thickness profiles of the wafers under uncertain measurement conditions. Specified factors of disturbing signals in spectroscopic data are analyzed regarding misalignment of the measurement instruments, surface integrity of wafers, and post analysis of spectroscopic data; for the causality inferences in the aberrant features in reflection spectroscopic measurements.
This work assessed the fundamental characteristics of multifunction cavitation (MFC), that was high-temperature and high-pressure cavitation, through both experimental investigations. The application of ultrasonication to the floating cavitation of a water jet was found to produce microjets containing hot spots. MFC exhibited the capacity to perform nano-level hot work at a material surface, modifying the surface morphology and the surface electrochemical condition by hot spot melting. Ultrasonic irradiation of a water jet during floating cavitation was used to generate microjets with hot spots and this MFC process was employed to perform hot work on titanium oxide (TiO2) particles as well as an ITO (Indium Tin Oxide) film on soda-lime glass and a steel surface.
In high speed machining, thermal stability of spindle has a great influence on the machining accuracy and the machining efficiency. Thermal instability of spindle is caused by the thermal deformation of spindle. Thermal deformation of spindle may be reduced by changing the material of spindle. Carbon fiber reinforced plastics (CFRP) has the advantage of low coefficient of thermal expansion. In this paper, thermal deformation and dynamic characteristics were compared for shafts made of steel and CFRP, using finite element analysis and measurement tests.
Silver nanowire transparent conductive film is expected as a new material for transparent electrodes because of its superior flexibility and electrical conductivity with high transparency at visible wavelength. Laser beam processing has been widely used for these application, and laser beam has the unique characteristic as an electromagnetic wave. Its feature has a great influence on laser-material interaction. However, these mechanism have not yet been clarified. Therefore, the polarization characteristics indicated by electric and magnetic fields were discussed, and effects of polarization direction on removal characteristics of silver nanowire transparent conductive film were investigated by using femtosecond pulsed laser with linear polarization.
This study investigated the effect of boron-doped diamond coated drill on cutting performance when drilling CFRP. The boron-doped diamond coating was deposited on cemented tungsten carbide with cobalt (WC-Co) drills with the hot filament chemical vapor deposition (HFCVD) method, adopting trimethoxyborane as dopant source. The coating characteristics, such as surface morphology and carbon bonds, were investigated by scanning electron microscopy (SEM) and Raman spectroscopy. Drilling tests included tool’s flank wear determination, measurement of thrust force and torque. For comparison, the conventional diamond coated and WC-Co drills were also used in the tests. Furthermore, drilled holes were inspected in terms of hole size and delamination. According to the results, boron-doped diamond coated drill showed advantage in tool life and quality of drilled holes over the conventional diamond coated and the WC-Co drills.
In the grinding wheel catalog data-set, the recommended grinding conditions are shown in reference to five factors (abrasive grain, grain size, grade, structure, and bonding material) of the three main elements (abrasive grain, bonding material, and pore). Since systematic arrangement is not made, grinding conditions (cutting speed, table feed, depth of cut) have to be decided on the basis of an experienced engineer's information or experience. Moreover, although the setting of the five factors of the three elements of a grinding wheel is important parameter that affects the surface quality and grinding efficiency, it is difficult to determine the optimal combination of workpiece materials and grinding conditions. In this research, a support system for effectively deciding the desired grinding wheel was built by using a decision tree technique, which is one of the data-mining techniques. This system extracts a significant tendency of grinding wheel conditions from catalog data. As a result, a visualization process was proposed in correspondence to the action of the grinding wheel elements and their factors to the material characteristics of the workpiece material.
At submerged laser peening, laser cavitation is generated after laser abrasion and it produces impact at cavitation collapse. In order to demonstrate mechanical surface treatment by submerged laser peening utilizing laser cavitation impact, alloy tool steel was treated and the residual stress was measured by X-ray diffraction methods. At submerged laser peening, Nd:YAG laser of wave length at 1,064 nm was used. The impacts induced by laser abrasion and laser cavitation were evaluated by a PVDF sensor which was installed in target. It was revealed that the submerged laser peening can introduce compressive residual stress into alloy tool steel.
This research work was carried out aiming to investigate the strain hardening in an aluminum alloy sheet caused by punch/die shearing by mean of a micro hardness measurement and finite element method (FEM) analysis. To examine the strain hardening zone at the sheared edge, a 0.36 mm thickness of AA4047 aluminum alloy sheared sheet was chosen. Then, it was prepared and subjected to the micro Vickers hardness test. In addition, a two-dimensional FEM model for the shearing of the aluminum alloy worksheet was developed and used for simulating the strain hardening. The effects of shearing parameters on the strain hardening were numerically analyzed. The results revealed that the micro Vickers hardness test was applicable for detecting the strain hardening zone at the sheared edge. Moreover, from the FEM simulation, we found that the maximum width of the strain hardening zone remarkably depended on the punch/die clearance and the friction at the worksheet/tool interfaces. The variation of the maximum width of the zone was explained by a critical level of the maximum principal stress in the worksheet being sheared.
In recent years, the need to reduce energy consumption at production sites has been studied because of the increased awareness of environmental problems. In this study, we focus on reduction gear with a strain wave gear incorporated in five-axis machine tools. Utilizing the characteristic of the efficiency varying with temperature, we propose a rotating motion as a warming motion of the swiveling shaft. We investigate the effect of the rotational direction and rotational speed, as well as the energy consumption, after the warmingup operation.
The focus of this study was high efficiency laser quenching and laser forming, which are simultaneously achieved by the laser quenching-forming method proposed in this paper. Laser quenching-forming is premised on laser scanning repeatedly. Therefore, it is necessary to consider the influence of heat accumulation by repeated laser scanning. The deformation angle when the workpiece was preheated was investigated. Quenching was evaluated for quenching from the viewpoint of hardening range, hardening hardness, cooling rate. Accordingly, deformation and quenching behavior using preheating conditions were determined. It has been shown that laser quenching forming is possible even by repeated laser scanning.
Pure titanium (Ti) and Ti alloys have been widely used as biomaterials. However, they have the disadvantage of lacking for bioactivity. Thus, adding a new function to Ti and Ti alloys is required. One method for adding new functions is controlled cell spreading by formation of periodic surface nanostructures on the biomaterials. In this study, the nanostructures were formed on the pure Ti by ultrashort pulsed laser irradiation, and influence of laser parameters on surface profile and discontinuity of the nanostructures was discussed. Moreover, influence of the shape variation of the nanostructures on control of cell spreading was investigated.
In this study, a method to reduce the tool approach mark due to the tool deflection by cutting force in ball end-milling operation is proposed. In order to reduce the approach marks, the influence of the tool deflection onto the machined surface is investigated. Characteristics of the tool approach mark are investigated based on the measured machined surfaces by a roughness tester. On the investigation, it is confirmed that the tool approach mark exists caused by the tool deflection and the tool deflection is copied onto the surface. A compensation method to reduce the tool approach mark by changing approaching point is proposed. It is also confirmed that the influence of the tool approach mark can be reduced by the proposed tool approach path offset.
Wire and arc-based additive manufacturing (AM) is one of the additive manufacturing which applies the arc welding technology. This process is especially expected to be useful in fabricating large-sized die and prototype machine parts. However, it is difficult to determine process parameters such as torch feed speed, welding current, welding voltage because the optimal process parameters depend on various factors such as material, target shape, deposition area condition. Estimation of the deposited metal shape in advance helps to determine appropriate process parameters. In this study, two-dimensional bead model for shell structure was proposed and built shape simulator was developed. Then, the accuracy of the simulator was investigated. As a result, accuracy of the simulator was about ±1mm in the area where the influence of deposition start and stop was small.
In grinding process, grinding wheel profiles are copied to workpiece surfaces. Therefore the finished workpiece surfaces can be estimated by the grinding wheel surfaces. In this paper, new measuring method of the distribution of cutting edges in grinding wheel surfaces by two AE sensors is proposed. From experimental results, it is confirmed that the distributions of cutting edges in wheel surfaces can be measured easily by the proposed method compared to other measuring methods developed so far.
It is important for product and material designers to forecast the performance and nature of the designing product early in the design process by computer simulation. The multi-scale product design and lifecycle simulation (MPDLS) system proposed here is a kind of multi-scale CAD system. The MPDLS system is designed to design the product or material across the micro-scale to the macro-scale continuously. Also, the MPDLS system includes product lifecycle simulation to estimates the ecological and economic efficiencies of the product. A MPDLS system prototype has been implemented using MPI-2.
Strong excitation at the chatter frequency results in the change of the phase shift between the dynamic cutting force and the displacement depending on the phase characteristic of machine tool. In this paper, the chatter was detected by monitoring this phase shift with the mechanical energy factor (MEF). To construct the sensor-less MEF monitoring system on the ball-screw-driven system, mode-decoupled cutting force estimation was applied to two inertia model, and the phase shift was monitored in the vibration mode. Through a milling test, the chatter vibration was detected in the vibration mode with low computation cost and simple threshold.
In response to the demand for high accuracy and high resolution of angular positioning and movement of CNC machine tools, the demand for rotary encoder systems has also increased for the detection of ultra-precise angular position and movement. Authors had developed a new principle of self-calibration with multiple detecting head which enables detection of the error components of higher order with the less number of detecting heads. In this study, the angular accuracy of the rotary encoder for servo control inside a machine tool was examined with reference to the self-calibration of the rotary encoder using the proposed method. Measured data of the accuracy of that were also utilized to generate the calibration data of the rotary encoder, and the rotary encoder was calibrated with the calibration data. The measured accuracy showed a resolution of 1/236. It was confirmed that the angular positioning accuracy was improved because of the calibration.
Current machining methods for polybenzimidazole (PBI) plastics produce a large number of fine cracks that reduce the strength of the machined surface. To reduce the cracking caused by milling, prior research focused on the cutting temperature of the workpiece and machining at about 700 K, the glass transition temperature for PBI. This produced a good crack-free machined surface, but it required a high cutting speed of 40 m/s to maintain the temperature, which is too fast for general machine tools. Here, we present a practical combined cutting method, using laser-assisted machining to reduce the cutting speed.
Thermal roll-to-roll nanoimprint (T-R2RNIL) using a flexible replica mold made of a special UV-curable resin was demonstrated. This UV-curable resin is able to be used for the nanoimprint process without a release agent. In this study, we examined the relationship between the hardness of the UV-curable resin and the transfer performance using flexible replica molds made of three types of UV-curable resins. The experimental result found that the special resin is a good candidate for fabrication of a replica mold for T-R2RNIL because of its high hardness and good release properties.
This study deals with the expansion of the diameter of a hole fabricated on the inside wall of another straight hole by means of electrical discharge machining. Although our research group has developed devices which can machine a hole inside another hole, the shape of the fabricated hole has been limited. Aiming to diversify the hole shape, this study has improved the device so that it can machine such a hole with a larger diameter. The experimental results indicate that such a hole with about 3.3 times diameter can be fabricated. As a result, it is proven that the improved device has the ability to machine a hole with a larger diameter inside another hole.
Formation of chromium carbide on the tool steel surface by EDM with chromium powder mixed fluid was examined in this study in order to discuss the applicability of inexpensive carbon tool steel SK105 to metal mold. Experimental results showed that the surface hardness, corrosion resistance, and releasability of molded resin from the surface were significantly improved by this method, since chromium carbide containing layer could be formed on the EDM finished surface. Moreover, hybrid powder mixed fluid EDM with chromium and silicon powders was proposed for further reduction in surface roughness. As a result, it was made clear that the formation of high functional EDM finished surface with smaller surface roughness was possible under optimum mixture ratio of chromium and silicon powders and EDM conditions.
The purpose of this study is to establish a method of estimating, in real time, the machining error caused by vibrations of the cutting point of an end mill. The vibration displacement at the shank of the end mill and the dynamic cutting force were measured during cutting tests while spindle speed was increased from medium to high. It was found that the vibration displacement, which was calculated by convolution of the dynamic cutting force and the impulse response of the tool system, showed a good agreement with the measured vibration displacement in all spindle speed range.
In nanosecond pulsed laser processing, laser beam irradiation normally induces plasma generation, which leads to the reduction of laser energy absorbed into a specimen. Therefore, material removal characteristics are strongly affected by phenomenon of laser induced plasma. Plasma generation is affected by pulse duration and laser intensity, but influence of plasma generation on material removal characteristics has not yet been clarified sufficiently. In this study, influence of pulse duration and laser intensity on plasma was investigated by measurements of transmittance of laser energy through the plasma. Finally, effective energy to material removal characteristics was discussed with calculated laser energy relating to removal volume of mild steel.
Displacement sensors based on laser or optical fiber technology are well recognized for the non-contact measurement of distance by reflection from the object. These technologies limit the distance of measurement along with the increase of resolution. The other option could be light wave interferometer built with the mirrors on the object. However, long distance measurement requires large and stabilized-wavelength laser source. This report explains another solution; non-contact, grating interferometer displacement sensor which enables Pico-meter resolution with semiconductor laser source.
For heat transfer performance improvement at boiling zone, minute unevenness with the various shapes to the generating surface is proposed in pool boiling. Growth of an air bubble influences big by the minute difference in the shapes. So it's the current state to predict correct heat transfer characteristics by an experiment. The purposes of this study are the specification of the minute unevenness which reduces one nuclear boiling arrival and consideration of the mass production method. And this report was estimated experimentally about the periodicity of the minute unevenness and the influence the looseness exerts on heat transfer characteristics.
In order to clarify the micro EDM deposition mechanism in fabricating 3-D micro sedimentary structures, a series of EDM deposition experiments were conducted using Cu-W electrodes with several kinds of diameters and a few types of discharge conditions under air and argon atmosphere, and the deposition processes of the melted electrode were mainly examined as the first step. At first, preferable EDM deposition conditions for fabricating 3-D micro sedimentary structures with enough heights were examined, and it turned out that the electrode diameters of around 100 μm or less are the most preferable for fabricating micro cylindrical and spiral sedimentary structures irrespective of the machining atmosphere. Then, precise observations of the deposition processes were performed using a laser microscope, and simple deposition models for the two different kinds of micro structures described above were proposed, respectively.
This paper describes influence of preload and retainer of linear ball guides on feed drive system in microscopic region which become important when the linear guides are used in precision machines. At first, relationships between nonlinear-spring-behaviors of the guide and behavior of quadrant glitches are analyzed based on proposed friction model. Behavior of the quadrant glitches, nanometer step responses and steady vibrations are also measured with the three different guide conditions; with/without ball retainers and preload changes. Time constant of the step responses are also analyzed based on the friction and control system model. From the analysis and experiments, it is clarified that the behavior of quadrant glitches and step responses are strongly influenced by the friction characteristics of the guides, and the behavior can adequately be estimated by the analysis. It is also clarified that the steady vibrations are also influenced by the friction characteristics, the amplitude of the vibration is proportional to the compliances of the nonlinear-spring-behavior.
Milling of thin-walled mechanical parts is limited by chatter, which affects surface quality. This paper concerns vibration analysis in milling with respect to nonlinear and non-stationer signals. Initially, a stability lobe diagram was created to determine cutting conditions. Therefore, hammering test was conducted to determine modal parameters. Following, milling tests were conducted under different cutting conditions. Data obtained in milling were analyzed by Hilbert-Huang Transform (HHT) and were compared with Fast Fourier Transform (FFT) results. HHT decomposes original signals into a series component, called IMFs, by empirical mode decomposition (EMD). Each IMF separated tooth passing, natural and chatter frequencies within frequency bandwidth used. Thus, the EMD made it easy to recognize the chatter growing as cutting depth was increased. The Hilbert transform is then applied on each IMF. The energy associated to chatter frequency increased in the Hilbert spectrum. The increasing of energy indicated the occurrence of chatter. HHT revealed the transition of machining state, from stable to unstable. The results showed that the HHT has an advantage over the FFT.
In current transfer machines for the conveyance of flexible bands, operation sometimes stops as a result of fluctuations in the tension of the flexible band, necessitating the readjustment of the machine and causing a reduction in productivity. Therefore, in this study, the factors influencing the positioning accuracy of the flexible band were clarified, and a method of monitoring the operating condition of the transfer machine was developed and with the ultimate goal of improving productivity. The results of this study indicate that the cause of the failure is the fluctuations in the torque of the transfer machine and the displacement of the part used to process the flexible band (processing part). To detect abnormalities in the tension of the flexible band, methods using a clamp-on ammeter, a rotary encoder, and a strain gauge were proposed. The displacement of the processing part was measured using a laser displacement sensor. Because the tension of the flexible band and the current and torque of the motor were found to show the same trends as the rotational speed of the motor was varied, it is considered that abnormalities can be detected by monitoring the current and torque. In addition, because the processing part apparently undergoes elastic deformation, it is necessary to determine the influence of this deformation on the machining accuracy.
In recent years, environmental degradation, highlighted by global warming and the transboundary movement of hazardous waste, has become a critical problem. In response to the deterioration of the environment, researches have turned their attention toward energy-saving technology. In particular, energy-saving machine tools indispensable for production sites is important. Therefore, in this study, an energy-saving tool path generation algorithm for a 5-axis machine tool was developed with a focus on minimizing the power consumption of the feed drive axis. Furthermore, an example the generation method was demonstrated for an overhang shape.
An important facet of the contouring performance of machine tools with computer numerical control (CNC) is the machining of workpieces within the desired accuracy and within as short a time as possible. However, conventionally, the accuracy (error) and the speed are evaluated separately. Therefore, in this research, a method is proposed to evaluate the speed and accuracy of CNC machine tools using two-dimensional expressions of error and speed based on actual trajectories. Experiments have verified that it is possible to quantitatively evaluate the speed and accuracy of multiple CNC machine tools using two-dimensional graphs of maximum error and actual speed.
This paper discusses a surface functionalization by the combination of surface modification with hydrophilic material and texturing. Modification of a silicon substrate with polyethylene glycol (PEG) is introduced first. Then, it was confirmed that PEG modified surface had stable oleophobic property in water for long time which can be applicable to self-cleaning characteristics. It was also found that array of micro-pillars well enhance the functionality. Lubrication function is also expected. Changing the normal load and sliding speed, coefficient of friction against steel ball (φ5 mm) was measured. It was found that good lubrication performance (μ 0.1) was observed under the condition of low contact pressure and low sliding speed.
The goal of this study was to perform additive fabrication onto the thin end of a plate using wire and arc-based additive manufacturing to repair turbine blades using Inconel 718. We investigated the relationship between lamination conditions and lamination width by fabricating a wall structure while maintaining a constant interlayer temperature. Results clarified that the lamination width is determined uniquely from a combination of wire feed speed and torch feed speed. By back calculating the combination of these two speeds from the target lamination width, we were able to roughly fabricate a wall structure with the target lamination width onto a thin plate end with a thickness of 1 mm or more.
The accuracy of a machine tool is depending on the estimation and compensation of deviation from the ideal kinematic. For machine tool builders the offsets of the rotary axes of five-axis machines can be difficult to measure, especially if it is a Cardan kinematic or if due to the positioning limits it is impossible to measure position at which the calculation is easy. Thus there is a requirement of software based measuring and compensation. Here a survey of approaches for measuring and compensation of five-axis machine tools and the achievable results is made.
In Directed Energy Deposition, which is one of the metal additive manufacturing methods, it is important to monitor the temperature of entire layered objects. For temperature monitoring, a non-contact measurement using a thermal imaging camera is desirable. However, it is difficult to measure the temperature of layered objects having large fluctuations in emissivity. Therefore, a method was proposed for measuring the average temperature of square areas on the surface using a single emissivity. The measurement result shows that the surface temperature of layered objects can be measured with sufficient accuracy using appropriate square areas.
This paper presents that the small displacement device to be driven by electro-magnetic force compensates the quadrant glitches which is one of machining error caused by dynamic motion error of machine tool table. New small moving device is designed and made by way of trial and the device is installed to spindle head of machine tool. The proposed compensation method is verified through simulation and experiment.
In this study, we have fabricated the arrays of convex microstructures on single crystal silicon (SCS) substrates using the procedure which includes two types of anisotropic etching process. We firstly fabricated the arrays of micropillars with vertical sidewalls using deep reactive ion etching (D-RIE) process of SCS. After that, we etched the micropillars additionally using the anisotropic wet etching process of SCS. We investigated the etched shape of the convex microstructures in the microfabrication procedure, and successfully fabricated the arrays with bilayer etching masks composed of the layer of aluminum and silicon dioxide with the controlled thickness.
The purpose of this study is to develop a novel mechanical vibration suppression method for high speed tracking motions. In this study, the mechanical vibration suppression method by applying vibration compensation torque to cancel the mechanical vibration during high speed tracking motions is proposed. In order to evaluate the effectiveness of the proposed method, rectangular corner tracking motions with applying the compensation torque are measured and simulated. As the results, it is confirmed that the proposed method can effectively suppress the vibration when the motion direction changes. It is also clarified that proposed method can effectively works for various feed speed by automatically adapting the torque based on the proposed criteria.
The purpose of this study is to clarify the influence of the torsional damping and the lead of ball-screw onto the vibration characteristic of the feed drive system. In this study, the measurement tests are carried out with a feed drive system consisting of an AC servo motor, a coupling, a ball-screw, and linear ball guides. It is clarified from the experiments that the feed drive system has three main vibration modes. It is also confirmed that the second vibration mode can directory be influenced by the torsional damping of the coupling, and smaller lead of ball-screw makes higher amplitude of the second vibration mode and lower amplitude of the first vibration mode.
Since cutting force acts on feed drive and spindle drive systems as force disturbance, feed speed and spindle speed are changed. As the results, cutting force is also changed. In this study, a coupled simulation method of the vibration of machine tool, the dynamic behaviors of feed and spindle drive systems and the cutting force is developed. Simulation results are compared with the experimental results, and it is confirmed that the vibration of the feed and spindle drive systems due to the cutting force can be simulated by the proposed method. It is also confirmed that the cutting force influenced by the vibrations can be expressed.
It is known that the machined shape errors occurred in the NC machine tools can be compensated by modifying the CL-data based on amount of the errors calculated by measurement results of workpiece shape. By this method, however, the shape errors cannot be compensate accurately in case of 5-axis machining, because the final machining shape may not a copy of motion trajectory of tool functional point due to the motion errors of translational and rotary axes. In this study, a modification method of CL-data which based on the amount of motion errors of tool center point trajectory during the machining motion is newly proposed. Simulation and experiment of wing profile machining motion is carried out to confirm the effectiveness of the proposed method. As the result, it is confirmed that the motion accuracy can significantly be improved by applying the proposed method.
The authors suggest a low fluence laser processing method for a power semiconductor wafer using a femtosecond double-pulse beam. In this report, we investigate the temporal variation of the surface reflectivity after the ultrafast laser irradiation as a result of a surface photo-excitation. In the double pulse processing method, the surface reflectivity is constantly high until 5 ps after the first pulse irradiation and then gradually decreased with increasing the time interval to shot the second pulse. In addition, the laser induced damage on SiC target is observed at a bottom of the ablated crater by using scanning transmission electron microscope (STEM). The thin amorphous layer whose thickness is about 10 nm can be observed at the ablated area.
Laser forming is a non-contact processing technique for metallic materials, which has usually been used for bending metal sheets. Because laser forming does not have spring-back compared with the conventional bending method, it is usually used for high-precision bending. In the previous research, the authors have successfully used laser forming for fabricating small, thin wire parts. However, it is very difficult to precisely control the bending angles because the heat capacity of the micro-wire is very small. In this study, the target is focused on the laser forming of micro-wire, with the diameter of 0.05mm. An error compensation method based on visual feedback is proposed. As a result, the dispersion of the bending angles by this proposed method can be achieved around 0.2 degrees.
Recently, 5-Axis machining centers have attracted attention in the mold manufacturing field where complex, high-speed and high-precision machining is required. ISO 10791-7, which is test conditions for machining centers, was revised in 2014. However, S-shaped test was proposed as an accuracy inspection standard for aircraft parts from China additionally and it is currently under discussion. In this research, the problems will be considered based on the S-shaped test proposed additionally as an annex to ISO 10791-7 in May 2015 and September 2016.
Along with the progress of processing technology on substrate, devices having a finer structure are being manufactured. Particularly in semiconductor manufacturing sites, the minimum unit has reached about 10 nm, and the existence of particulate defects of several nm affects the yield, so inspection techniques with higher sensitivity than conventional methods are required. Therefore, we propose an optical inspection method of nanoparticle defect based on a new principle that liquid is used as a probe. In this report, we introduce the phase contrast microscope for high sensitivity of the proposed method and report on the result of characteristic analysis.
It is strongly expected that sintered tungsten carbides, having extremely higher hardness and heat resistance than conventional steel materials, will be utilized widely as molds and dies. In this study the cutting performance of the diamond-coated tools in milling of sintered tungsten carbide is examined through a series of cutting experiments of nine types of sintered tungsten carbide workpieces bonded together in 10wt%, 15wt%, 20wt% or 25wt% cobalt on a 3-axis vertical machining center.
Recently, high heat density has become a problem in electronic devices. Therefore, high heat-transfer efficiency is required in copper heat exchangers. Previous studies have reported that a copper oxide layer enhances wettability. In this study, we focus on a copper oxide layer produced under warm conditions (from 200 to 300°C), which are suitable oxidation conditions for improving wettability.
Experimental results showed that the hydrophilicity was enhanced by the warm copper oxide layer. The surface roughness was approximately constant. The results from SEM observations showed that the warm copper oxide layer consisted of stacks and combinations of nanoscopic warm oxidation particles.
Surface structures and crystalline microstructures are the key factors to control surface functions. Through the combination of plastic deformation and heat treatment, it is possible to fabricate surfaces with predesigned textures and thus gain control of surface functions. However, the link between metals in deformed state and the resulting microstructure after annealing remains uncovered. In this work, plastic deformation through tensile test and following static recrystallization in annealing are carefully studied. In-situ observations were performed to trace the microstructure evolution during annealing. The results have shown that the nucleation tend to happen at sites with largest strain gradient and the grain boundary generally migrated along  planes in grain growth. These preliminary conclusions may help to control surfaces microstructure for development of functional surfaces.