Ultra precision dry cutting by diamond tool with heat sink layr

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Since the content of minute diamond particles involved in the electroless-plated Ni・P layr is about 4wt% ( : 6.6Vol%), the thermal conductivity of the layr is not large enough as a heat-sink layr for temperature control of cutting edge of diamond tool. It is observed a constant cutting force in wet cutting. But a changeable force in dry operation is observed and this becomes from the change in true depth of cut by thermal elongation due to cutting heat. Temperature increase of diamond tool in dry cutting is nearly three times of that in wet cutting. Recession amount of cutting edge of the tool is small, but it is obtained from a change in the contour of cutting edge made by plunge type cutting. Surface roughness by wet cutting is nearly the same as the theoretical value, but that by dry cutting is several times of the theoretical one. From the SEM photograph of chips the uniform layrs are observed all over the free surface of chip formed by shearing deformation. Several obvious lines along the chip flowing direction are observed over the surface rubbed against rake face. Along these lines, sometimes, series of small holes are found or the chip is separated and hence only narrow chips are observed. Mirror surface are not made on aluminum workpiece by dry cutting.