In buffing stainless steel, it is necessary to decrease defects such as microscratches and improve the finishing efficiency. In this study, the role of the grease contained in buffing compounds was investigated to clarify the mechanism of scratch generation and action of material removal. The grease was shown to have a large effect on scratch generation as the binder that strongly ties buff fibers together and holds grains, cutting chips, and any hard materials present in the processing atmosphere. On the basis of the mechanism, compounds containing fine urethane particles were newly developed to decrease microscratches by inhibition of retention and hardening of grease. A series of stainless steel buffing experiments indicated that the new compounds along with adjusting the quantity of grease maintained good finishing efficiency and reduced microscratches.

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In cylindrical plunge grinding, thermal deformation of a workpiece due to grinding heat can make it difficult to fulfill the requirement of dimensional accuracy. Therefore, prediction of the thermal deformation in the grinding process is expected to reduce the dimensional error. In this study, an in-process system for prediction of workpiece thermal deformation during cylindrical plunge grinding was developed. In this system, workpiece thermal deformation is estimated without measuring the grinding force. The grinding force is calculated from the measured surface temperature and stock removal rate, which can be measured easily. The temperature distribution in the workpiece is derived from the calculated grinding force and the thermal deformation of the workpiece can be predicted. Good agreement was achieved between the estimated thermal deformation of the workpiece and the experimental results.

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Single-crystal sapphire wafers were cleaved by irradiation with a pulsed CO₂ laser. Laser cleaving is a useful method to cut sapphire wafers. A striped pattern on the cleaved surface is observed when a pulsed laser is used. Laser cleaving makes it possible to cut the sapphire along the circular arc. Sapphire wafers can be cleaved by laser irradiating along a pre-made shallow groove.

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