Fabrication And Experimental Research On Grinding Performance Of Novel Micro Grinding Tools

As mechanical and electrical products gradually become miniaturized,lightweight and multi-functional,the contradiction between the quality precision,processing efficiency and production cost of small parts has become prominent.High quality,high efficiency and low cost processing of complex shape of micro-size parts has become a difficult problem to be solved in the manufacturing field.Micro-grinding technology,as a micro machining method which can obtain nano-scale machining accuracy,micro-grinding technology has broad application prospects.However,due to the tight distribution of abrasive particles coated on the surface of micro grinding tools and the narrow chip holding space,the working surface of micro-grinding tools is easy to produce blockage,which leads to the characteristics of fast wear and short service life of micro grinding tools.Service life of micro grinding tools has become one of the key factors restricting the application of micro grinding technology.Considering that the conventional micro grinding tools have the problem of fast wear and short service life,a novel micro grinding tool with chip-holding structure on the surface was proposed,in order to enhance the chip-removing ability of the novel micro grinding tools and improve their service life.Specific research contents are as following:(1)Based on the principle of LS-WEDM turning,the parametritis model of chip holding structure of novel micro grinding tool was established,and the mapping relationship between chip holding structure parameters and process parameters was obtained.The static simulation model of the novel micro grinding tools and the flow field simulation model of the micro grinding contact area was established to reveal the chip removal and friction reduction mechanism of the chip containing structure.The experiment of LS-WEDM turning technology was carried out to complete the high quality machining of the novel micro grinding tools matrix.Experimental research on plating process of novel micro grinding tools was carried out to solve the difficult preparation problem of novel micro grinding tools with a diameter of 800μm.(2)Based on the theory of brittle fracture mechanics and the grinding processing,considering the chip structure characteristics,the surface morphology simulation model of brittle material machined by new type micro grinding tools was established,and the surface formation mechanism of brittle material machined by the novel micro grinding tools was revealed.Sapphire micro-grinding process experiment was carried out to explore the influence of chip structure parameters of the novel micro grinding tools on surface quality of brittle material.(3)Based on contact mechanics and indentation fracture mechanics,considering the micro-contact between abrasive particles and workpiece,the micro-grinding force model of the novel micro grinding tools was established to reveal the mechanical characteristics of brittle materials processed with novel micro grinding tools.Sapphire micro-grinding process experiment was carried out to compare and analyze the variation rule of micro-grinding force of the novel micro grinding tools,and the corresponding relationship between micro-grinding force and surface roughness Ra was obtained.The etching experiments on sapphire surface machined with novel micro grinding tools were carried out to obtain the influence of chip structure parameters on the depth of damage layer.(4)The wear contrast experiment between the novel micro grinding tools and conventional micro grinding tools was carried out to explore the influence of the chip structure on the wear form and morphology of the micro-abrasive,and the wear rate changes of novel micro grinding tools and the conventional micro grinding tools were compared and analyzed.The variation rule of machined surface roughness Ra with the amount of material removed was obtained,and the wear resistance mechanism of the novel micro grinding tools was revealed.