This paper deals with an analysis of the cross-sectional chip area and cutting performance of radius end milling of an inclined surface using a contouring and scanning cutter path method. At first, the modeling of a cutter, an edge, a rake surface and a workpiece with an inclined surface are carried out using 3D-CAD. Secondly, the cross-sectional chip area is calculated by the interference of the rake surface and the uncut chip volume. The influence of the cutting method and the direction of pick feed on the behavior of the cross-sectional chip area. And also, the influence of the inclination angle of the machined surface on the maximum cross-sectional chip area is shown. In addition, the cutting force and surface roughness are measured by cutting tests and the cutting processes are examined. Finally, cutting conditions which would produce a good cutting performance are considered.
Printings of rough and large patterns with widths or sizes of 10-100μm are often required for fabricating various micro- or mini-size components. However, low-cost and convenient lithography tools specialized for these pattern sizes are not available. For this reason, a new scan-projection lithography using a gradient-index (GRIN) lens array as a projection lens has been proposed. Using the GRIN lens array, 1 : 1 erect images of the reticle patterns are projected onto a wafer in a wide oblong region. Accordingly, patterns in a large area are printed by synchronously scanning the reticle and wafer at a constant speed. However, caused by the lens array structure and individual differences between element lenses, exposure dose is distributed in the lens array direction. For this reason, back-and-forth sub-scan along the lens array line is adopted. As a result, pattern width distribution is drastically leveled, and almost homogeneous 12.5-μm line-and-space patterns are printed, though patterning margins are very small. Pattern-width homogeneity and exposure-dose margin will probably be improved by replacing the sub-scan stage, and increasing the sub-scan speed. Patterning margins will also be extended by adjusting the projection ratio more precisely. The proposed system is promising for the aimed patterning.
Anisotropic materials including glass fiber reinforced plastics (GFRPs) are used in various fields because of their superior mechanical properties such as high specific strength. The machinability of these materials has been extensively researched in the field of cutting. On the other hand, a few reports on the machinability in the field of abrasive machining have been published. However, there are very few reports on loose abrasive machining. The present study investigates the influence that an orientation angle of reinforcement fibers and a particle size of abrasives on the lapped surface morphology of GFRPs, and discusses the surface generation mechanism in loose abrasive machining. The major results obtained are as follows. The lapped surface morphology depends on the orientation angle of reinforcement fibers. In the case of the particle size of abrasives is 11.5μm, the lapped surface roughness deteriorates with decrease in the fiber orientation angle. A chipping width of reinforcement fibers decreases with fining the particle size of abrasives. In the case of the particle size of abrasives is less than 3μm, the transition from brittle to ductile material removal occurs. The maximum surface roughness is less than the particle size of abrasives under brittle material removal in loose abrasive machining. The use of the particle size of 2.0μm provides a good surface with little fracture of reinforcement fibers.
Nano-machining requires precise positioning of a tool on a workpiece when the start of machining or the tool is exchanged during the machining. In the 1st report we obtained the positioning repeatability of 20nm by supplying voltage between the tool and the workpiece and detecting current variation between them using the restricted voltage and current at the level of Scanning Tunneling Microscope (STM). In this report, the effects of factors affecting on the positioning repeatability is discussed and the positioning repeatability of 5nm is obtained by using a improved detecting circuit. Additionally it is confirmed that this is non-contact positioning system, where the tool and the workpiece does not contact during the positioning.
This paper introduces a fast and reliable object detection method for situations in which a target object is surrounded by similar objects. Sample image sets of the target object and similar objects are prepared in advance. And pixels that maximize the separability between these two classes are automatically selected. Robust image matching for similar objects is achieved using these pixels. In addition, processing time for image matching is reduced by using a small number of pixels. Through experiments using 400 actual images, a recognition success rate of 98.5% was achieved by using approximately 0.5% of whole pixels of the template image.
Demands for ultra-precision machined surface such as semiconductor wafer are rapidly growing. However, because of shrinking design rules of the semiconductor, it is uprising the difficulty of detecting nano-defects. To keep process yield in manufacture line, we must develop a defect measurement system with higher resolution, throughput, non-destructiveness and robustness. As such a measurement system, we have proposed the application of the structured light illumination (SLI) microscopy. The proposed method is optical inspection system and that resolving power exceeds the diffraction limit. Conventional proposed method has a difficulty about imaging system. Despite the imaging system is coherent system, the imaging system required in conventional super-resolution algorithm is incoherent system. We proposed algorithm based on coherent system, and three-light-flux interference standing wave illumination that enables new algorithm usage. In the fourth report, to verify super-resolution method with coherent image iterative reconstruction experimentally, we develop the experimental apparatus. As the result of basic experiment, 230nm structure which can't be resolved by conventional method is resolved by proposed method, under the condition of Rayleigh limit 541nm.
Chatter vibration deteriorates the machining accuracy and shortens the tool life. Thus, In-process monitoring methods have been proposed by using additional sensors such as dynamometers and acceleration sensors. However, introducing additional sensors leads to high cost and reduction of machine-tool stiffness. To solve these problems, a sensor-less monitoring method applying the disturbance observer theory was proposed in our previous research which has experimentally shown that chatter vibration can be detected only from the servo information in milling. For further demand, because chatter vibration can be classified into self-excited vibration and forced vibration, an assorted detection method is required. In this study, we propose a novel frequency analysis method combining moving variance and moving Fourier transform algorithms, which can obtain the power spectrum density of each chatter vibration type separately with small computational load. The validity of the proposed method is evaluated through milling tests with different rotational speeds.
In a previous study, we developed a new method for observation of the whole cylindrical surface in a very short time,using a laser microscope with a wide field of view. When cylindrical specimens were rotated by a motor-driven rotary table, the focused laser light was scanned along a generatrix of the cylinder surface. Thus, the whole cylinder surface could be observed easily even over a very short time. As the obtained image was a developed view of the cylinder surface, it was easy to measure the distance between any two points on the cylindrical surface. In this study, we acquired interference images of the whole cylinder surface with the aid of a reference plane. As a result, fringe patterns over the whole cylinder surface could be obtained. From image processing of the fringe patterns, we calculated the nanoscale surface profile of the cylinder.