Drilling experiments of CFRP/Ti6Al4V laminated stack board were carried out using of a TiN/AlN-coated cemented carbide drill and a TiAlCr/TiSi-coated cemented carbide drill. Under the experimental conditions described here, tool life was longer for lowered feed speed, and the TiAlCr/TiSi-coated cemented carbide drill had longer life than the TiN/AlN-coated cemented carbide drill. In addition, the cooling performance between dry process and water-mist-cooling were compared. The thrust and error of the hole diameter were both smaller for water-mist-cooling. Water-mist-cooling reduced tool abrasion for hole numbers of less than 100. However, the abrasion increased suddenly for hole numbers greater than 100 as in drilling at colder temperatures by water-mist-cooling, the chip may not curl and adhere to the drill.

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Hole-making in CFRP is generally done using drills. However, exit burrs and delamination occur around the hole. Therefore, we propose a new processing method with a dual-axis-driven grindstone mechanism. This mechanism has not only grinding wheel rotation but also right-angled rotation. This processing method makes it possible to drill a hole in CFRP. We present the basic performance of the drilling process using the dual-axis-driven grindstone mechanism.

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A cutting tool-type single-point diamond dresser, the tip of which has a given rake angle, was developed and its dressing and grinding performances for a small-diameter grinding wheel were investigated. The results indicated that the back rake angle of the dresser affects the grinding wheel surface topography, and the dressing mechanism changes its mode from ductile to brittle mode with increasing back rake angle in the negative direction. The cutting tool-type dresser exhibits good robustness compared with a single-point diamond dresser and multipoint rotary diamond dresser as the ground surface roughness is not markedly affected by the dressing conditions but is determined by the back rake angle of the dresser.

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Blasting is a machining method used for microholes or grooves on hard and brittle materials, such as glass and silicon, and is now beginning to be applied in manufacturing in medical and semiconductor fields. Blasting is applied for machining of flat surfaces in many cases, and some applications have been reported. However, the application of blasting is expected to extend into industrial fields, if blasting could be applied for micromachining of 3D-shaped surfaces. In this study, machining characteristics in cylindrical blasting were experimentally investigated, with analysis of stock removal, surface roughness, and the machined surface state to obtain fundamental information regarding blasting of cylindrical surfaces. Abrasive grains of green silicon carbide make finer surfaces rather than those of white fused alimina in blasting of C3604. The offset of blasting nozzle against the workpiece axis enhances the machining efficiency.

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This study was performed to investigate the effects of ball end mill rake surface on cutting characteristics. Grinding wheel grain sizes of #325 to #1000 were used, and rapping chips were added. The PVD coatings used were TiAlN , TiSiN, and CrSiN. Cutting resistance, tool wear, and the cutting surface were examined. The results indicated that the ideal grinding surface roughness was different near the edge and at the rake surface. Near the edge, it was necessary to keep the surface area small, as a sharp edge can easily bite into the material to be cut. However, the rake surface did not need a small surface to reduce cutting resistance because of changes in the region of contact between the rake surface and cutting chip.

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