The electric rust preventive machining method that uses only water as the machining fluid has been developed. The water recycling system in the rust preventive machining method can remove very fine particles and ions from water. Therefore, removal of various contaminants from the water (water for water-soluble cutting fluid, rinse water, etc.) is possible. In this investigation, using a water recycling system, purification of water containing cesium (¹³³Cs, 1 mg/L) was examined. The cesium removal rate of 99.6% was achieved. In addition, the quantity of refined water was 10.5 L/min. Moreover, the removal ratio of 96.43% was indicated in the concentrated water of reverse osmosis membrane. It is thought that it is caused for adsorption of unique adhesions on membrane.

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Small, high-performance products made of hard brittle materials, such as glass and ceramics, are increasingly attracting attention. Ultrasonic machining (USM) is an effective method for fabricating various structures on hard brittle materials. However, when machining size is reduced to the sub-millimeter range, as the size of abrasive grains is in the micrometer range, machining efficiency of USM becomes low. In this study, to obtain guidelines to improve machining efficiency of USM, the mechanism of material removal in USM was analyzed by the smooth particle hydrodynamics (SPH) method. The simulation results indicated that the material and shape of abrasive grains in the slurry used in USM markedly influence the machining efficiency. Finally, experiments indicated that USM with spherical alumina as the abrasive grains in the slurry showed high efficiency.

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To investigate the effects of friction-work on fatigue properties, rotary bending fatigue tests were performed on friction-worked S45C steel specimens in laboratory air at room temperature. Tests were also conducted on electropolished specimens for comparison. The results indicated that the fatigue strength of friction-worked specimens was considerably improved compared with that of electropolished specimens. This was due to the high compressive residual stress and the work-hardened layer, which consisted of submicron grains formed on the specimen surface by friction-work. In addition, the coaxing effect appeared for friction-worked specimens as a result of stress-incremental tests.

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This paper describes the cutting characteristics of lithium niobate, which is used for surface acoustic wave type micro pumps, with regard to the formation of micro grooves by direct cutting. As lithium niobate is a brittle material with strong crystal orientation dependency, significant differences were observed in the characteristics of the finished surface with different directions of cutting. The ductile mode cutting of lithium niobate was found to be feasible with cutting depths of approx. 5μm or less. In addition, results of the study indicated the feasibility of the formation of minute grooves through cutting of lithium niobate using milling with an end mill.

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