| Micro-features are usually used in the core product of micro-machining devicemechanism and system; it has significant theoretical value and application in IT,energy, environmental protection, biology, medical and national defense. Ultraprecision mechanical indentation is one of the most important methods of precisionand ultra-precision machining. This method use elliptical validation assistedapparatus making continuous high speed indentation with PCD die which may haveone or thousands of micro-feature arrays to obtain ultra precision molds which thefrequency can even reach1KHz.After then ultra precision molds are used to producemicro-features in volume production. So in compare with other micro-machiningtechnology, elliptical vibration assisted ultra precision indentation has manyadvantages:(1) Comparing with MEMS lithography, ultra precision mechanicalindentation has cheaper cost of making molds;(2) Comparing with mechanicalprocessing such as turning and milling, ultra precision mechanical indentation canobtain smaller geometry shape and has no risks of interference;(3) Comparing withthermochemical imprint processing, ultra precision mechanical indentation arecapable of manufacturing of varieties of materials, not only soft material, but alsohard metal, even hard brittle material. All in all, ultra precision mechanicalindentation has significant value of research and application.However, in order to produce ultra precision mechanical indentation with highefficiency and quality, the most important issue is the development of a newapparatus for elliptical vibration indentation with high precision and frequency.Therefore, the following issues are concerned seriously:Firstly, the development of ultra precision mechanical indentation process beganby doing research in indentation theory, investigating indents created using a standardhardness tester and comparing the results to an ANSYS finite element analysis (FEA)simulation.Secondly, the matching issue between elliptical vibration machine and precisionmachine, the elliptical tooling path, indentation parameters are also consideredseriously. After that the relationship of tool spindle speed, feed-up and frequency arebuilt which is important in indentation experimentThirdly, a non-resonant two-dimensional elliptical vibration assisted indentationapparatus is designed by using flexible hinge In this paper, three row symmetricalflexible hinge mechanism oriented the two independence movement, three motionaxes are staggered to each other, flexible hinge mechanism is to be designed integrateto avoid assembly errors. The PICMA type piezoelectric stack drive the flexible hingemechanism directly, the Microsense TM II5300-type capacitive displacement sensorare used to detect the displacement feedback. According to the layout to optimizeflexible hinge mechanism, the main dimensions of the components are used to designvariables, stress, frequency and elastic restoring force as the constraints, the minimum reduce the required parasitic motion in the plane as the objective function, andultimately draw the corresponding parameters optimize the value of obtained thisoptimization parameters stiffness, frequency and maximum stress values.Last but not the least, the offline test is made to check the performance of theapparatus. The finite element based on design results validates the analysis and theactual stiffness test. Analyzes the stiffness of the two directions: Y to42.13N/μm, Zto32.15N/μm, the first natural frequency:1111Hz. The test is derived to test thestiffness of the Y and Z three directions, respectively40.32N/μm and32.26N/μm,system resonant frequency is228Hz in the experiment and1111Hz in the simulation.The resolution ratio can achieve10nm in Y direction and9nm in Z direction. Its steptracking performance is proved to be good. In addition, the apparatus is proved to bedecoupled completely. The test results verify the validity of the calculation andanalysis, fully able to meet the test requirements. |
PDF Full Text Request