This paper describes the elucidation about the removal of Fe-42wt% Ni alloy (It abbreviates as alloy 42.) surface oxidation layer after heating processing using dilute electrolyzed oxidizing water. Almost, it clarified that electrolyzed oxidizing water could remove the surface oxidation layer of alloy 42, by the immersing experiment and the surface analysis of the samples. Next, it made clear when the barrier operation of the high nickel concentration area which was formed by heating processing, was cause about that the dissolved oxygen in electrolyzed oxidizing water didn't diffuse to the samples surface layer after the heating processing. Moreover, by the oxidation layer removal experiment which used the samples of the existence or non-existence of the heating processing, it reinspected that electrolyzed oxidizing water could remove alloy 42 surface oxidation layer after heating processing. Like oxygen, as for carbon there was not diffusion to the sample surface layer. The results indicate that electrolyzed oxidizing water can, indeed, be applied to remove alloy 42 surface oxidation layer after heating processing.

抄録全体を表示

CMP is the standard planarization method for silicon wafers. For environment reasons, semiconductor manufacturers have to reduce the consumption of materials, such as slurry. The oscillation-speed-control-type polishing machine uses a small tool and supplies slurry from a pad center, so the slurry spreads to the polishing area easily. This report shows the polishing characteristics under low slurry flow rate conditions. In non-oscillation polishing, it is difficult to reduce the slurry flow rate to less than 200 ml/min since a shortage of slurry results in a damaged area on a wafer. In uniform oscillation speed polishing, no damaged area was found to occur even with a slurry flow rate of only 5 ml/min. In addition the experimental results corresponded with the simulated ones. It was demonstrated that in oscillation speed control polishing, the minimum oscillation speed and slurry flow rates were different for different pad materials. In experiments, a flatness of better than 0.2 μm over the entire surface was achieved using both an IC1000 pad with a slurry flow rate of 20 ml/min and a SUBA800 pad with a flow rate of 40 ml/min.

抄録全体を表示

This paper describes the limit of miniaturization of micro EDM using the electrostatic induction feeding method. In this method, it is possible to minimize the influence of the stray capacitance existent parallel to the working gap because the point of electric feeding can be located near the working gap. Hence, the minimum discharge energy is smaller than that of the relaxation pulse generator. As a result, the diameter of discharge craters of this method was 0.4μm, smaller than that of the relaxation pulse generator by 0.3μm. Therefore, the minimum diameter of rods obtained using this method was 0.8μm, smaller than that of the relaxation pulse generator by 0.1μm. Moreover, the success probability of fabrication of micro rods thinner than 2.0μm in diameter was two times higher than that of the relaxation pulse generator.

抄録全体を表示

This paper describes the machining characteristics of the electrostatic induction feeding method. With the conventional relaxation pulse generator normally used in micro electrical discharge machining, since the gap voltage begins rising after the end of the previous discharge, it is difficult to keep the minimum necessary discharge interval between pulse discharges to recover the dielectric breakdown strength of the gap. Thus, localized discharge and abnormal arc easily occur, resulting in machining instability. Moreover, since discharge even occurs before the capacitor is fully charged due to the long time constant of the RC circuit, it is difficult to obtain uniform discharge energy per pulse. In contrast, with the electrostatic induction feeding method, since only a single discharge occurs for each cycle of the periodic pulse voltage, the discharge gap can be cooled regularly during the discharge interval, resulting in stable machining. Therefore, machining characteristics of the electrostatic induction feeding method were investigated using the machining system newly developed for micro-hole drilling. Machining results show that the machining speed of this pulse generator is higher than that of the relaxation pulse generator in micro-hole drilling, especially when rotation speed of the tool electrode is low.

抄録全体を表示

High-aspect-ratio microdrilling of borosilicate glass has been demonstrated by the forth harmonic of nanosecond Nd : YVO₄ laser. Borosilicate glass plate with a thickness of 2 mm was drilled through. Firstly, the profile of the drilled hole was measured. As a result, diameters were φ8.2 ± 3.1 μm andφ6.3 ± 1.0 μm at the depth from 480 μm to 2040 μm and from 1360 μm to 2040 μm, resulting in an aspect ratio of higher than 190 and 100, respectively. Drilling process was observed by ceasing laser illumination every 500 pulses. Depth of the drilled hole increased ∼200 μm by very 500 pulses. Re-deposition layer with a thickness of a few micrometer was observed in the range from the top surface to a depth of 1600 μm. Inner surface of the drilled hole was observed by scanning electron microscope (SEM). Melted surface was observed at around the surface (in the range ∼100 μm from the surface) area. Debris with diameters of less than 500 nm was observed in the range of 100 μm - 600 μm from the surface. At around 650 μm, debris with diameters of 500 nm - 1 μm were recognized. In the area deeper than 700 μm, no clear debris was observed and flat surface was obtained. Cracks were observed in the same area where the re-deposition occurred.

抄録全体を表示

In order to experimentally assess effects of MnS morphology on growth of built-up edge (BUE) in low carbon free cutting steel, quick stop tests were conducted for a leaded steel and two non-leaded steels which contained different type of MnS inclusions. Deformation structure in chip shear zone of tested specimens was microscopically observed. In the leaded steel, micro-cracks grew from the deformed globular shaped MnS in the vicinity of BUE, which seemed to contribute to form a small BUE. It was clarified from TEM observation that this small BUE was composed of elongated fine ferrite subgrains microstructure, in which a lot of fine cementite particles dispersed. In the non-leaded steels, the BUE originating from the non-leaded steel containing the globular shaped MnS was small similar to the leaded steel, but one from the steel containing the slender shaped MnS developed bigger. The difference in size of BUE was affected the surface roughness in the non-leaded steels. It is considered that difference in deformation characteristics of different type of MnS affects the size of BUE through the generation of micro-cracks in the shear zone in the vicinity of BUE.

抄録全体を表示

The research aims to build the high mass production system for ultra-smoothness polishing of double sides of workpiece. For the aim, the linear motion type of double sides polishing method is newly devised. Furthermore the linear motion type of machine which is possible to polish continuously without the rest or with a short rest of polishing operation by feeding linearly the workpiece parallel to linear movement of polisher is manufactured on trial. By polishing the magnetic disk substrate with the trial machine, the possibility of application of the new method to double sides polishing is examined. Using the new machine, double sides polishing of the substrate is roughly ascertained possible.

抄録全体を表示

This study aims to develop nano-level image storage, “Nano-blackboard” with nanoscopic additional processing, using an atomic force microscope (AFM) probe as chalk and glass as blackboard. This study also clarifies the optimal conditions for using chalk, and proposes a theoretical formula to estimate the volume of wear particles and transfer particles left on the blackboard. This formula is based upon thermodynamics, because chemical reactions are responsible for wear of chalk. The volume of wear particles and transfer particles calculated using this formula are consistent with the obtained experimental values. Furthermore, character shapes are fabricated efficiently by processing under optimal conditions based on this formula.

抄録全体を表示

The UBMS (UnBalanced Magnetron Sputtering) method is applied to the coated end mills and some kinds of such tools are used in high-speed milling of SUS304. This coating film is designed to improve lubricating ability rather than heat resistance. TiCN film deposited by UBMS method (U-TiCN) has smooth surface and low coefficient of friction. XPS analysis reveals that the U-TiCN film includes many free carbons rather than carbide phases, and this structure acts as lubricant as well as thermoprotective film. Long tool life and good finished surface quality are obtained with U-TiCN coated end mills than standard commercially available coated end mills in high-speed side milling without coolant. An U-TiCN end mills having a low coefficient of friction suppress adhesion of workpiece material and overlap of chips to the cutting edge.

抄録全体を表示

In machining of products in which a large number of cutting tools and machining processes are required, the sequence in which a workpiece is machined has an effect not only on factors relating to productivity such as machining time, machining cost, and power consumption, but also on the machining error and quality of the machined surface. However, the number of combinations of processing sequences for machining of such products is extremely large, and it is therefore difficult to design an optimal machining process within a short time. In this study, an algorithm for solving the shortest path problem is used to develop a process planning support system that takes into account the various above-mentioned factors in machining using a machining center. The system incorporates various functions such as prevention of interference between the tool and the workpiece resulting from the machining sequence, prevention of processes in which previous machining is invalidated, and integration of processes performed using a same tool. Machining times based on NC data are calculated, and the shortest machining time for a product requiring 15 processes (using 9 tools) is analyzed. A comparison of results obtained using the proposed system with machining times required for processes designed by operators confirmed that the analytical results are valid.

抄録全体を表示

This paper describes trajectory design using clothoid segments. As a trajectory path, clothoid is superior to the other curves because its curvature varies linearly with its curve length. However, a single clothoid segment is not able to match both tangent and curvature designation at its terminals because it has no sufficient parameters. In our study, “triple clothoid” is introduced to match both tangent and curvature designations. The triple clothoid is a set of three clothoid segments connected internally with curvature continuity. It has sufficient parameters needed for tangent and curvature matching at its terminals. The triple clothoid segments are used to construct a smooth transition passing through arbitrary point sequence. The resultant trajectory possesses curvature continuity and matches all tangent and curvature designations at the giving points. Those results are extended from two-dimensional (2D) to three-dimensional (3D) space. In 3D space, a predefined 3D clothoid is used to construct triple 3D clothoid. The resultant 3D trajectory also possesses kinematical superiority because of its differential linearity in both pitch and yaw angles. The triple clothoid can also be used for connecting two straight segments with curvature continuity.

抄録全体を表示

The H-slit beam structure is an effective structure used in design of force sensor. It can enlarge sensitivity while it keeps enough rigidity and stiffness. One of the characteristics of the H-slit beam structure is that its deformation pattern is same as that of a four bar link mechanism. In this kind of mechanism, it is highly important to show recovery from deformation force under specific distance between the parallel beams. Like a Roberval balance mechanism, the H-slit beam structure is also capable of moment canceling though the mechanism involved in it has not been explicitly developed. This paper investigates the efficiency of the H-slit beam structure by comparing the generated strains of it with that of the Roberval mechanism. Here the strain is calculated by using FEA (Finite Element Analysis) and experimental models. All of the results show that the H-slit beam structure is effective in canceling the moment due to the distance between strain signal sensing position and loading position. The results also demonstrate that when the distance between two parallel beams in the structure is too narrow, the structure will become ineffective for moment canceling.

抄録全体を表示

The research deals with a novel modeling and compensation approach for the transmission error in harmonic drive gearings. This paper, as the first report, presents a mathematical modeling framework for nonlinear components in the gearing, where nonlinear friction, nonlinear elastic characteristic, and angular transmission errors are handled to provide a precise numerical simulator. In the modeling of transmission errors, physical phenomena due to nonlinear elastic deformations in micro-displacement region are especially dealt with, as well as the synchronous component which has been already discussed in a variety of conventional studies. Based on the analyses of the phenomena, the nonlinear elastic component can be mathematically formulated by applying a modeling approach for the rolling friction with hysteresis attributes. Numerical simulations and experimental results using a prototype show the effectiveness of the proposed modeling.

抄録全体を表示