In the previous report, a new dynamic grinding model capable of incorporating the effects of cutting path density and machine tool stiffness was described. Here, the proposed model was verified in an empirical study. The results demonstrated that the dynamic grinding model can provide a better explanation of interference between the cutting edge and substrate, and the geometric profile generated in comparison to the conventional static model. Following the optimal conditions obtained through simulation by the dynamic model, an extremely flat wafer with PV less than 0.5μm has been successfully achieved in infeed grinding scheme.

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This study was performed to develop a new ultra-precision magnetic abrasive finishing process. This process uses a new type of "magnetic abrasive slurry" made by mixing super-minute spherical iron particles, super-minute abrasive grains, and oily grinding liquid. When internal finishing was performed, the stirring phenomenon of the magnetic abrasive slurry occurred, and super-minute abrasive grains and minute iron particles were uniformly distributed in the magnetic abrasive slurry. Thus, a super-precision internal tube surface could be created. Internal magnetic finishing experiments of SUS304 stainless steel tubes were performed with a magnetic abrasive slurry consisting of spherical carbonyl iron particles (6μm in mean diameter) and diamond abrasive grains (0 - 0.25μm in mean diameter). The results indicated successful creation of an ultra-precision internal surface, and it was confirmed that the initial surface roughness of 320 nm Ra could be improved to 5 nm Ra.

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The authors have developed an electroconductive porous rubber-bonded wheel to enhance finishing characteristics in ELID grinding, and investigated the electrolytic dressing characteristics and grinding characteristics of this grinding wheel. In this study, we fabricated grinding wheels with #400 SiC abrasives, and ground Ti alloy by ELID lamp grinding. Experimental results showed that electrolytic dressing forms a layer with large specific wear and frictional coefficient on the grinding wheel surface. We also conducted ELID grinding experiments of Ti alloy, and the results confirmed that the grinding wheel maintains grinding performance and the ground surface has excellent tribological features.

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In this study, we investigated a technique for precision machining of microgrooves and pockets on hardened materials with a high aspect ratio. First, we studied fabrication of micro-end mill made of sintered cBN as a super hard material. We obtained micro-cBN end mills with a diameter of 30 μm and an aspect ratio of 5. Second, we studied a cutting technique using the fabricated micro-cBN end mills. We applied an ultrasonic cutting method to the above micromachining. The results indicated that the micromachining of grooves and pockets with a high aspect ratio can be realized by applying the ultrasonic cutting method using the fabricated micro-cBN end mills.

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