The influence of microshot peening on the surface layer characteristics of high-speed tool steel was investigated. A compressed air-type microshot peening apparatus with a heating furnace was produced experimentally. Peening microshots, 0.1 mm in diameter, were made of cemented carbide, and the workpieces were made of high-speed tool steel. The surface roughness, compressive residual stress, and hardness of the peened workpieces were measured. The effects of processing temperature on the surface layer characteristics by warm shot peening were also examined. The use of hard microshots was shown to cause a significantly enhanced peening effect for high-speed tool steel.

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To develop efficient ELID grinding technologies, our research efforts include the development and enhancement of elemental technologies of ELID, and R&D of special machine tools. As part of these research activities, we have developed a prototype aluminum-bond grinding wheel using the accumulative roll bonding method to investigate the basic characteristics of the grinding wheel. We used aluminum alloy (Al2017) and WA abrasives to prototype the grinding wheel and investigated the basic characteristics of the grinding wheel, such as bending characteristics, frictional wear characteristics, initial electrolytic dressing characteristics, etc. Using this accumulative roll bonding method, we also prototyped a radial type grinding wheel and conducted experiments. The results confirmed that the grinding wheel is able to maintain removal ability by ELID.

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This paper describes a new magnetic field-assisted deburring process in which burrs can be removed without changing the edge shape of precision machine parts. This process is not subject to the waste fluid processing problem, and it provides an environmentally conscious processing technology. In addition, the remnants of burrs from handwork can be resolved, and the automation process and high-quality deburring can be achieved. In this study, the finishing characteristics were examined using various magnetic particles. The experimental results indicated that polygonal magnetic particles have the optimum shape.

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Co-Cr alloy used as a biomaterial must show excellent resistance to corrosion and wear, as well as biocompatibility. In the present study, we performed Electrolytic In-Process Dressing grinding on Co-Cr alloy, and evaluated the processing characteristics and resulting surface properties. Final finishing using a #8000 wheel produced an extremely smooth ground surface with a roughness Ra of 7 nm. In addition, the ground samples showed superior surface hardness and biocompatibility in comparison with conventionally polished samples. These advantages can be attributed to the diffusion of several types of element during the grinding process and the effects of grinding fluid composition.

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