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Parameter Optimization Of The Surface Roughness Of B4C Engineering Ceramic In WEDM

Posted on:2008-06-14Degree:MasterType:Thesis
Country:ChinaCandidate:C M YuFull Text:PDF
GTID:2121360212994459Subject:Mechanical Manufacturing and Automation
Abstract/Summary:PDF Full Text Request
B4C engineering ceramics is focused as a very important material for its excellent performance of physics and chemistry. Its rigidity is inferior to diamond which challenges the traditional machining method and restricts its application badly. For the electrical resistivity of B4C is 0.3-0.8?·cm in normal temperature and the EDM can machine the material whose electrical resistivity is less than 100?·cm, the EDM becomes the key method for the wide application of B4C .Wire electrical discharge machining is an unconventional method which machines the material with a soft wire. The feasibility of machining with EDM is only related to the electrical resistivity no matter how hard it is which is different from traditional machining method. The difference from the traditional machining method is made use of to machine the B4C engineering ceramics which is not accomplished by traditional machining method. This paper based on the research results both here and abroad, mainly completed two part research items. One research is about the effect rule of ti, toff/ti and ie to the finished surface quality, the other one is to optimize the combination of the three parameters in order to maintain the best combination.The single factor experimentation of the three parameters discussed the effect rule of ti, toff/ti and ie to the B4C engineering ceramics finished surface quality and analyzed the micro view of the finished surface through ESEM getting a straight understand. The differences are discussed trough the contrast between the experimentations of both metal and B4C engineering ceramics. The disfigurements—crack and"knurl"of the finished surface are found in the contrast experiments of the peak current which are explained through making the removal mechanisms clear. In the contrast experiments of the toff/ti, the rules of effect for both metal and B4C are unified by the curve of"the three ranges curve of the finish surface quality and toff/ti"which proved that the effect rule of toff/ti for finish surface can be explained by only one theory curve no matter what the material is.The best combination of the three process parameters is optimized by the orthogonal test which is got by the design of the experiment technique. All the data of the results is analyzed by analysis of range. The primary and secondary effect factors and the optimized combination of the three process parameters are got through different data processing of the experiments data which are obtained through different measurement. And the results are validated later to make the final decision.Some researches are made about the effect rule of the process parameters for the finish surface, the differences between metal and B4C are found through contrast experiments and the reason is explained in theory and practice. The optimized combination and the satisfying surface quality are gained through the orthogonal test, with the roughness by straightforward measuring reaching 0.369μm and by perpendicularity measuring reaching 0.414μm. But the cognition for the removal mechanisms is not clear yet.
Keywords/Search Tags:WEDM, B4C engineering ceramics, Process parameters optimizing, Finish surface, Orthogonal test
PDF Full Text Request
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