Despite the large number of methods available for deburring the outside of parts, it is difficult to remove burrs on the inside of small and long parts. Here, a new magnetic internal deburring method is proposed. This method applies a magnetic field-assisted machining process using a magnetic machining jig (permanent magnet tool). The machining force applied to the magnetic machining jig can be controlled freely by adjusting the clearance between the outside pole and magnetic machining jig. A flexible half-fixed finishing behavior can be obtained, because finishing can be achieved through magnetic particles attracted to the magnetic machining jig. In this study, we examined deburring of a hole drilled on the inside of SUS304 stainless steel tubing. The results showed that internal burrs could be removed using this magnetic deburring process.

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Three-dimensional finite element analysis for Vickers indentation on soda-lime glass was performed. The time-dependent stress distributions around and below the contact area during the indentation cycle, especially at the end of loading and at the beginning of the unloading phase, were investigated in detail. The results indicated that when the indentation depth was set to 2μm, at the corners of the indentation from beginning unloading the tensile stress increases dramatically and reaches the maximum value. It can be predicted that the radial cracks nucleate mostly from beginning of unloading at the shoulders of the indentation and propagate along the diagonal of the impression. Furthermore, the tensile stress below the contact surface increases considerably from unloading, which may explain why the lateral cracks nucleate from unloading half cycle. The analytical results were in good agreement with the experimental results.

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Demands for the development of dry cutting technology are increasing, as such processes do not require use of cutting oil and are therefore environmentally friendly. This study was performed to clarify the cutting mechanics in dry hobbing, and to develop guidelines for practical application of dry cutting in hobbing. Experimental investigations were carried out to cut SCr420 alloy steel with high-speed steel hobs, flank faces of which were coated with TiAlN, and the tool wear and adhesion of chips onto the cut surface were analyzed. It was shown experimentally that crater wear on the rake face of the hob is reduced when cut under dry cutting conditions as compared to conventional wet cutting. The adhering chips protect the rake face and the suppress generation and growth of crater wear. On the other hand, there are cases where the cutting accuracy is reduced due to the chips adhering to the rake face. The adhesion of chips can be eliminated by changing the chip formation process. It was also shown that the adhesion of chips could be predicted from the tooth height coefficient and the average thickness of the chip generated between the pitch circle and the tooth bottom.

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This report describes micro-fabrication of polytetrafluoroethylene (PTFE) to make a micro-fluidic device. The micro-cutting process was employed for fabrication of required elemental micro-structures, such as micro-channels and micro-reservoirs, for the device. In general, burrs are generated easily in the cutting of soft materials, such as PTFE. It is important to determine how to prevent burr generation and how to clean the generated burrs to ensure device quality. To obtain fundamental information about burr generation in the micro-cutting of PTFE, through-hole drilling, groove milling, and face milling were performed. Elemental micro-structures without burrs were fabricated on PTFE plates. Furthermore, the plates were sealed with sealing film assisted by pressure. Testing leakage with fluid samples confirmed that the pressure-aided sealing was useful.

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