Research Of Mechanisms And Heat Characteritics In Axial Power Ultrasonic Honing

The technology of power ultrasonic honing is a kind of effective untraditional processingmethod in the fields of precision and ultra-precision machining, especially in the fields ofbrittle-hard materials processing, which has a broad application prospect for low cutting force,temperature and high processing efficiency, surface quality. Grinding temperature is one ofthe most important physical quantities in the grinding process affecting the workpiect surfacequality, it has being studied that ultrasonic grinding processing can reduce the grindingtemperature effectively, but there is no systematic theory to explain the internal mechanisms.The paper mainly discussed the grinding heat in the axial power ultrasonic honingcombining theoretical study and numerical analysis, stated the machining characteristics ofultrasonic honing, analysed producing machanisms of grinding heat in ultrasonic honing, anddiscussed the internal reasons for temperature reducing in ultrasonic honing, which providefoundmental theories in the research of grinding heat of ultrasonic grinding. The researchcontants can be summarised as fllowers:1. The paper expounded the mechanisms, kinematics characteristics and the phenomenonof empty cutting in the power ultrasonic honing; the feasibility is demonstrated that theductility processing of brittle materials with ultrasonic honing, based on the theory ofindentation fraction mechanics.2. The model of effective abrasive grains numbers on the oilstone surface was establishedby the theory of statistics, taking into acount the grains distribution and the grains numberworked as actual cutting effect; assume that the brittle material was removed in ductility, forcemodel was builded consist of chip deformation and grain-workpiece fraction based on thesingle grain cutting; the force formulas of single oilstone were derived combine with theultrasonic honing kinematics characterics, and it was compared with traditional honing withdifferent machining parameters by numerical analysis. 3. Primary cause that grinding temperature reducing with ultrasonic was analysed by theaspects of machining characteristics, adiabatic shear, and ultrasonic cavitation; grinding heatmechanism was analysed according to the material removal processing, and the relationsbetween process parameters and specific grinding are discussed; the models of heatdistribution and coolant convective heat transfer on the grinding zone in the ultrasonic honingwere established, the value of coolant convective heat transfer coefficient with ultrasonic is9times than ordinary honing, which enhance the coolant efficiency and reduce the grindingheat transferred to the workpiece, consistent with the text results.4. The temperature distribution model was set up on the grinding zone of ultrasonichoning, according to the moving heat resource theory and the superposition principle; assumethat the NdFeB material was machined with diamond abrasive grain under the coolant ofparaffin, the numerical analysis of temperature distribution on workpiece can be presented byMATLAB, the results can be concluded that the temperature of workpiece surface withultrasonic is average50%lower than traditional honing, and the cooling effect is morepronounced with higher honing speed and depth.