Reaserch On ELID Gringding Mecha-Nism And Cutting Performance Of Nano Cemented Carbide

Nano cemented carbide is superior to common cemented carbide in properties, such as high hardness, toughness and strength. Nano cemented carbide has wide use in places such as some hard-wearing die, tool and cutter (for example: microtool), etc. Research focus of the nano cemented carbide is concentrated on preparing technology of nanometer powder, spraying technology, sintering technology and friction and wear per-formance, and cutting performance etc., but research of ultraprecision processing mechanism and technology of the nano cemented carbide is relatively less. So, explore ultraprecision processing technology and mechanism of the nano cemented carbide, to turn the nano cemented car-bide into application, and to expand their application fields have impor-tant significance.ELID (Electrolytic In-process Dressing) grinding technology is new technology of ultraprecision grinding, that is developed for the past few years. The oxide film is formed on grinding wheel by electrolytic in-process technology, thus the wheel is in-process dressed. Performances of the oxide film of wheel surface on grinding process and grinding sur-face quality have important influence. It's good for grinding difficult to machine materials as hard and brittle materials etc. To obtain good results grinding cemented carbide by ELID grinding technology. So, prepare grinding nano cemented carbide by ELID grinding technology.In this paper on the basis of research progress in country and oversea for ELID grinding technology, the thickness, contact stiffness of the oxide film on wheel surface in ELID grinding are systematic researched. Fur-ther ELID grinding mechanisms for nano cemented carbide are researched. On the basis of research progress in country and oversea for nano ce-mented carbide and its processing technology, the friction and wear per-formances and cutting capability are researched.First, the thickness, and contact stiffness of the oxide film on wheel surface in ELID grinding is systematic researched. When the wheel is electrolyzed by pulse power, set up calculate model of the oxide film thickness and go on theoretical simulation and experimental researches, from the pulse electrolysis capacity this new angle the non-linear elec-trolytic reason in ELID grinding is announced. Set up calculate model of the oxide film contact stiffness and go on simulation and experimental analysis, the characteristic, that oxide film contact stiffness with grinding changing is reflected, self-adapting law of the oxide film in ELID grind-ing has showed.Second, from the performances of the oxide film, base on the theory of minimum thickness of cut (MTC) the surface micro topography for-mation mechanisms of nano cemented carbide in ELID grinding are re-searched. MTC is theoretically analyzed and simulated, and microcutting mechanism of sharp grits and burnishing mechanism of passivating grits is theoretically analyzed, simulated and experimentally researched a little. ELID grinding mechanisms of nano cemented carbide are studied, because the hardness is relatively high, and grinding forces are relatively great, make oxide film larger elastic deformation, and actual depth of cut (ADOC) of a grinding wheel is small. At the same time, because the effect of stiffness coefficient of the oxide film, the nano-burnished of the pas-sivating grits included in the oxide film makes ELID grinding surface quality of the nano cemented carbide better.Third, friction and wear performance of nano cemented carbide is experimentally researched. The coefficient of friction and hard-wearing of nano cemented carbide are studied by ball-on-disk friction and wear tester, the worn surface is observed by SEM, and the wear mechanism is studied. Results have suggested, as the crystalline grain degree is reduced, the coefficient of friction of nano cemented carbide has the tendency to reduce, and the wearability of nano cemented carbide is reduced with the cobalt contents increase. The cobalt content of nano cemented carbide is different, the wear mechanisms are prominent and different, the WC-7Co shows the crystalline grains come off, the WC-10Co shows the plastic flow.Fourth, based on ELID grinding technology new style nano-cutters are manufactured and its cutting performances are generally researched from the sharpness and wear rate of cutter. The blade is accurately ground by ELID grinding technology, and the edge radius on blade is researched by AFM. The white cast iron and aluminium base composite material is cut by nano cemented carbide cutter; the cutter wear rate is measured, set up cutter wear rate model, and carried on preliminary simulation and experimental analysis. Results have showed, good agreements between the predicted and measured tool flank wear land width show the devel-oped tool wear model can accurately predict tool flank wear to some ex-tent.