森田 昇

In order to improve the laser micro-machinability of borosilicate glass, the glass surface was doped with metal (silver or copper) ions by an electric field-assisted ion-exchange method. Doped ions drifted and diffused into the glass substrate under a DC electric field. The concentration of metal ions within the doped area was approximately constant because the ion penetration was caused by substitution between dopant metal and inherent sodium ions. Nanosecond ultraviolet laser irradiation of metal-containing regions produced flat, smooth and defect-free holes. However, the shapes of holes were degraded when the processed hole bottoms reached ion penetration depths. A numerical analysis of ionic drift-diffusion behaviour in glass material under an electric field was also carried out. The calculated results for penetration depth and ionic flux showed good agreement with the measured values. ? Published under licence by IOP Publishing Ltd.

The measurement of cutting force is important to monitor the status of the process during micro drilling. It is used the cutting dynamometer, the shape of the workpiece is restricted and must be set to the center. These problems can be resolved by adoption of the spindle with built-in sensor. The purpose of this study is the development of the sensor built-in spindle for micro drilling that the thrust and the torque can be measured simultaneously. The structure of the spindle uses a static pressure bearing and a capacitance sensor to realize high accuracy measurement. As a result of study, this spindle was able to measure very weak thrust and torque to occur by micro drilling of 0.05mm in diameter. These results of research can be constructed the advanced processing system which prevents the breakage of the drill by monitoring the cutting force.

The relationship between the grinding conditions and AE wave in constant-cut surface grinding was considered for the purpose of examining the cognitive technology of a situation of grinding. Grinding of fine-ceramics generally advances by a brittle fracture. This report was considered the processing model of constant-cut surface grinding based on the Vickers hardness test. And, the amplitude of AE was formulated based on two kinds of cracks generated from this processing model. It was predicted that the amplitude of AE wave and the chip coefficient are a correlation. Some grinding experiments were conducted in order to examine the validity of the calculation formula. As a result, although some problems remained, relationship between the grinding conditions and the amplitude of AE wave was clarified. From this result, the guideline which predicts the situation of grinding using the amplitude of AE wave was acquired.

Soft composite materials are used for a functional film for a thermal interface material. The surface of this functional film must be flatter and thinner, and contacting fillers to have a better thermal conductivity. Cutting would meet these requirements to slice such soft materials. Soft composite materials consisting of acrylic rubber bulk and graphite fillers were prepared and sliced into films (1mm thickness) as thermal interface materials by developed cutting method. Measurements of curl radius and cutting forces were conducted on the orthogonal cutting experiments. It was found that the following three strategies were effective for reducing curl of chip and cutting force: (1) higher operating temperature, (2) slower cutting speed, and (3) larger tool rake angle. This result suggested a useful method for the effective slicing by controlling the cutting conditions.

In this study, brittle materials were mechanically modified under precise normal force control at the mN~/i,N level using PCD tools as a nano tool. The lab-made PCD attached micro cantilevers were customized for tribo nanolithography. The machined patterns were measured under an atomic force microscope (AFM) to obtain the machining characteristics of the samples for each set of conditions. Then the samples were etched using aqueous solution to verify the etch characteristics of the machined surface. Our results showed that either protruding or depressed patterns could be generated on the scratched surface by controlling normal load, scan pitch, and etching condition. The unique mask effect of brittle material after mechanical scratching under PCD tool can be controlled by the conventional mechanical machining conditions such as chip formation, plastic flow, and material removal. We used SEM, TEM, SIMS, and AFM to investigate the etch characteristics and structural change of brittle material under nano scale mechanical machining conditions. ? 2010 American Scientific Publishers.

Single crystalline silicon were mechanically modified (TNL, Tribo nanolithography) under precise normal force control at the mN ? μ N level using PCD tools as a nano tool. The machined patterns were measured under an atomic force microscope (AFM) to obtain the machining characteristics of the samples for each set of conditions. Then the samples were etched using aqueous solution to verify the etch characteristics of the machined surface. We used SEM, TEM, SIMS, and AFM to investigate the difference in etch characteristics and mechanical properties produced under various mechanical machining conditions. Our results showed that either protruding or depressed patterns could be generated on the scratched surface after chemical etching by controlling the normal load and the etching condition. In addition, the mask effect of brittle material after mechanical scratching was controlled by the conventional mechanical machining conditions such as contact area, chip formation, plastic flow, and material removal. Then, this study will be preceded to hybrid electrochemical nanolithography applications in near future. ?2010 IEEE.

There are three processing modes of fine-ceramics, which are ductile mode grinding, brittle mode grinding, and composite mode grinding. Composite mode grinding is the mode which the ductile mode grinding and the brittle mode grinding blend. In this paper, grinding processing models of ductile mode and brittle mode under the constant cut surface grinding was composed, and the grinding force was formulated from these grinding processing models. It was assumed that grinding force in composite mode grinding is proportional to the ratio of the removal volume of ductile mode and brittle mode. In addition, the removal volume of brittle mode was assumed to be proportional to exponential distribution. As the result, the calculated grinding force was well corresponding to the grinding force obtained by experiment. Therefore, the possibility of evaluating the grinding force from both mechanical properties of fine-ceramics and grinding condition was found.

This study aims to develop novel cutting tools that have either microscale or nanoscale textures on their surfaces. Texturing microscale or nanoscale features on a solid surface allowed us to control the tribological characteristics of the tool. In this report, the textures were applied to drills with the diameter of 0.5 mm and drilling experiments of aluminum alloy were performed to evaluate the developed tools. The texture decreased thrust and its fluctuation range under the high feed rate conditions. This effect depended on the direction of the texture and lower thrust was observed when the texture was perpendicular to the chip flow direction rather than the parallel. The breakage resistance could be improved utilizing this phenomenon. These results indicate that the developed tool is effective as a drill for small holes.