Precision processing of ceramics by the raster machine

Abstract

Ceramic materials processing techniques have been briefly presented in the article. The process of grinding, lapping as well as the stages of technical ceramics processing have been reported. Up to 80% of the material to be removed at the first stage, where a rough tool was utilized for machining at high speed. At stage second, the fine grain instrument was employed for the grinding process. Thus, the volume of the grinded material is reduced. At the third stage, lapping is performed by diamond abrasive flour grains and pastes of the necessary granularity. After the stage of lapping the polishing of the surface is done to achieved high accuracy and elegant finish. The investigation of abrasive lapping of the parts made of VSH-75 oxide ceramics material. It has been found that the efficiency of the diamond flour grains is 15-30 times greater than the efficiency of Al2O3 and SiC flour grains. With the increasing of granularity, the volume of the total material removal and surface finish enhances. In order to obtain the highly finished surface (Rz=0.8 µm), it is recommended to use ASM20 synthetic diamond flour grain. The influence of the part’s contact pressure (range 25-150 KPa)on the lap has also been investigated. The volume of the total removal is distinctly increased with the increase of contact pressure from 25 to 50 KPa, while the diamond discharge intensity and the processed surface finish reduces. Further, the contact pressure increases up to 150 KPa exhibited deep scratches and machining marks on the tool surface which seriously impairing the tool. The optimal contact pressure for the superior ceramics lapping on the cast- iron lap SCH-28 should be in between 50-100 KPa