| Al2O3ceramic has been widely used in MEMS for its great properties, such as high hardness, resistance against erosion, high temperature and abrasion. What is called pre-sintered is sintering on the temperature degree lower than which of wholly-sintered. This paper was focused on a new way in machining ceramic. Firstly micro3-dimensional structures were machined. And then the pre-sintered ceramic was sent to be wholly sintered. Through this processing way, we can overcome the disadvantages in traditional way of machining ceramic. In this paper’s research, processing way of machining pre-sintered ceramic was studied, and machining gap sintering shrinkage, Tool wear compensation and triple ladder cavity with small size of the error was processing.Green ceramic bodies were produced on press machine with different pressure, and the effect of pressure on density of green body were analyzed, the approximate linear relationship between pressure and green density was clear. The conclusion was drawn that with the increase of pressure, adding amount of density was decreased slightly. We obtained pre-sintered body in the conditions of sintering temperature is800℃, holding time is10h. Density of pre-sintering body was analyzed. And there is no significant change in pre-sintered body’s density because without shrinkage happened.The shape of tool was designed based on machining features.2flute end mill designed was no obvious radial wear in the processing of the cavity, end face have a good wear shape, the height difference of end face is usually less than5μm. Processing cavity bottom surface is less than2.6μm.Narrow grooves were machined on pre-sintered bodies, Using clean up debris on tool surface first then no cut into process to clean up residual debris, Clear debris effect is obvious, This method improves the recognizable of contour, Created favorable conditions for the accurate measurement of the size of the processing characteristics. Drilling, milling cavity experiment on pre-sintered bodies, machining gap of holes and cavity was measuring. Machining gap of holes is larger than Machining gap of narrow groove, which is larger than Machining gap of cavity, Shows that machining gap was larger when chip removal was harder. The shrinkage of the holes, the pitch of holes, and the cavities was measured; Shrinkage of holes was larger than the shrinkage of pitch of holes. The shrinkage of pitch of holes is consistent with the shrinkage of cavityThe impact of Machining force on the amount of tool wear was studied, found when the tool end face wear into spherical, with machining continuing the shape of tool end face remains unchanged, and Tool into the state of linear wear. Machining forces and tool wear were linear correlation when removing the same volume of material. Because of machining force of a single cavity is generally stable, thus the rate of tool wear is considered constant, To provide a basis for tool wear compensation.Three stepped cavity was made, length of side design size of stepped cavity were800μm,1000μm,1200μm after sintering, The actual manufacturing of error within±2μm; design size of depth dimensions are100μm After sintering, the actual manufacturing error control within±4μm. Satisfactory results are obtained. |
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