Study Of Micro Deep Drawing Process Of Foil Conical Parts

Lubrication plays an important role in the micro-forming technology, but thetraditional lubrication methods are largely restricted due to the existence oftribology size effect produced by the miniaturization of specimen size. Mold surfacemodification technology provides a completely new lubrication method formicro-forming technology. Diamond-like carbon film (DLC film) has advantagessuch as low friction coefficient and good wear resistance etc. so it has broadprospects in the mold surface modification. However, the DLC film preparedthrough traditional methods has low capacity binding to the substrate, it has greatimportance to improve the ability of DLC film binding to the substrate and researchthe lubrication conditions fitting for Foil Micro-forming.Transition layer DLC films was deposited on Si surface with a voltage of20kVby plasma ions implantation, then with the changing sputtering voltage, the surfaceof DLC films were prepared on the basis of the transition layer membrane, whichconstituted the DLC functionally graded film (referred to DLC film). In this paper10kV,13.5kV,16.5kV and20kV were chosen as sputtering voltages to prepare DLCfilms. The properties analysis of thin films was studied by atomic force microscopy,Raman spectroscopy, scratch test and nano-indentation test.The results showed that the results showed that with increasing sputteringvoltage, the graphitization of the DLC films increased, and when the surface filmsputtering voltage was13.5kV, the DLC film particles arranged in neat rows, with alow friction coefficient and high intensity, had good overall performance.With the tensile test the wear failure mechanism of DLC film was studiedunder the conditions of lubrication and plastic deformation. The results showed that,compared with without lubrication, when use the DLC film lubrication, the frictioncoefficient between the specimen and the indenter was significantly reduced, in theexperimental process, the DLC films of indenter surface was wear failure, and themacroscopic failure mechanism was abrasive wear, and the micro-failuremechanism was the chemical bond changes.The simulation for cone deep drawing was built to optimize the parameters ofthe forming process, which showed the best starting position of the blank holder was down to0.3~0.4mm to the die when the T2purple copper foil was in the deepdrawing.A cone-shaped deep drawing mold was manufactured based on the simulationresults. The influence of the forming force and material status to the materialformability during the deep drawing process was studied, and the results showedthat with the increasing drawing speed, the maximum forming force requiredreduced; the material formability was sensitive to the holding temperature instead ofthe holding time. The mold surface modification was done though depositing DLCfunctional graded film with a voltage of13.5kV. Then the micro-deep drawing testwas performed, as a result T2purple copper foil parts with good surface quality anduniform size distribution were get.