| 摘要 |
PURPOSE:To improve shape accuracy and the accuracy of the roughness of a finished surface and to shorten the time of working to a greater extent by converting a surface to be worked to a hard and brittle material contg. silicon to an amorphous state and projecting a short wavelength laser in the presence of an aq. electrolyte to the surface thereof. CONSTITUTION:While the work 1 which is; for example, Si3N4 hard and brittle material, is transferred in a direction 2, a porous elastic body impregnated with the aq. electrolyte 3 of a supplying device 4 is brought into contact with the unworked layer 1a of the rough surface by the coarse crystal particles to coat the liquid 3 on said work. An aq. Ca(OH)2 soln. or the like which allows easy electrolytic dissociation of water and can accelerate the hydration reaction of SiO2 is used for the liquid 3 and an electrode mounted to the device 4 is energized to accelerate the electrolytic dissociation of the water. Extreme projecting parts 13 are then ground by a diamond grinding wheel 5 and the surface thereof is converted to the amorphous layer 1b by aggregating the fine crystals of the roughness conforming to the roughness of the grinding wheel. The short wavelength laser 9 is projected to the layer 1b which is held coated with the liquid 3 to change and soften the Si3N4 in the front layer to the hydrate of SiO2. The softened layer 1c is ground by a diamond blade 11.
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