Recently a productive high efficiency and high grade finished surface machine technique has been required because of the demand for high quality components. Thus, there is an increasing need for an appropriate grinding technique. There have been few studies on grinding characteristics of fluid. In this study, grinding of steel (SKD11) with a cBN wheel was investigated. The results indicated that extreme pressure additives have a marked influence on the grinding wheel face. The normal grinding force is increased markedly by use of emulsion containing extreme pressure additives. When total wheel-workepiece contact is high, the use of grinding fluid containing extreme pressure additives is effective to grinding characteristics.

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In this study, the correlations between surface quality and contamination in coolant were investigated on the assumption that chips produced in grinding and abrasive grains released from a wheel affect the work surface. The number of scratches, which is one of the most important problems in production fields, in relation to sludge and abrasive contents was systematically summarized. The experimental results showed that the number of scratches increased monotonically with increasing sludge contents, and remained constant at 50×10⁷/l. Meanwhile, abrasive grains in coolant were dominantly involved in the formation of scratches, and had a 40-fold impact on the number of scratches rather than sludge. Moreover, optical microscopy indicated that configurations of scratches could be categorized as linear-type or curve-type. Whereas the former was observed with increasing sludge contents, the latter emerged with contamination of abrasive grains.

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In dental Nd:YAG laser therapy, a quartz optical fiber is generally used to transmit the laser beam for caries treatment and periodontal tissue excision. As normal optical fiber has difficulty irradiating a narrow space and the inner root canal uniformly, it is effective to use a processed optical fiber tip that allows a diffuse and circumferential laser beam. To obtain such laser beams, a new process with titanium dioxide (TiO₂) powder was proposed in a previous paper. The present paper describes use of zirconium dioxide (ZrO₂) powder, manganese dioxide (MnO₂) powder, and silicon dioxide (SiO₂) powder to process the fiber tip, and the processability of the fiber tip with these powders was evaluated. The influence of the weight concentration and radiation conditions on a straight laser beam at the fiber tip was investigated. The results indicated that the straight laser beam from the processed fiber tip decreased with increasing weight concentration and laser energy per pulse, and TiO₂ powder was most effective for processing of the fiber tip.

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This study was performed to clarify the effects of machining environments and conditions on the diamond grinding process of silicon wafer. In this study, the lubrication effects due to air on material removal were examined by nano-scratching using a scanning probe microscope (SPM) under air and vacuum. For comparison, molecular dynamics simulations were also performed by changing the dissociation energy of a Morse potential function between a pair of Si and C atoms to evaluate the lubrication/adhesion effects. The experimental and simulation results confirmed that lubrication due to air is effective for reduction of subsurface damages, grinding forces, and tool wear, but is accompanied with reductions in material removal rate.

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