Grinding Mechanism Research On Ultrasonic Vibration Honing Processing Nd_Fe_B

The ultrasonic honing is the application of vibration cutting in the honing, which provides a new effective method for the processing of hard brittle material. The paper analyzed the grinding mechanism of ultrasonic vibration honing processing Nd_Fe_B, established the kinematics and dynamics model and discussed the mechanism of grinding, material removal model and the processing efficiency, which has the very vital significance to promote the application of the Nd_Fe_B permanent-magnet material in the engineering.The paper has conducted the research and the discussion mainly from the following several aspects.1. The present research situation of ultrasonic vibration process technology, the ordinary honing and the ultrasonic vibration honing are elaborated. The Nd_Fe_B material's physical property, the processing present situation and so on have been researched.2. Analyzed the grinding mechanism of the ultrasonic vibration honing and the vibration cutting kinematics characteristic. The unique spatial cutting phenomenon and the supersonic cavitation effect have been pointed out. The spatial cutting phenomenon has reduced the working pressure, the grinding temperature and the distortion of craft system and so on. The supersonic cavitation effect forms the supersonic air bubble or the cavity, which distributes around the abrasive. Once bursts, the instantaneous pressure is several thousand times atmospheric pressure, thus forming the intense shock-wave, which provides the supersonic energy for the superficial material's elimination and raises the honing processing efficiency.3. When we used the turning, milling and wire electrical discharge and so on conventional methods to process Nd_Fe_B material, it's easy to appear brittle collapses, the tool wear excessively quickly, bad processing quality and so on. In order to meet the Nd_Fe_B material's precision sizing, the special ultrasonic vibration honing resonance system has been designed.4. When ultrasonic vibration honing processing Nd_Fe_B material, each abrasive on the oilstone has the impact characteristic, the speed change characteristic and the reciprocate irons and press characteristic. When ultrasonic vibration honing processing Nd_Fe_B permanent-magnet material, with the function of the high frequency vibration, the single abrasive's trace is longer than ordinary honing in unit of time, which raises the processing efficiency.Analyzed the vibration cutting process of the single abrasive grain and established the single degree-of-freedom and two degree-of-freedom dynamics model. In the foundation of the single abrasive grain's dynamics model, the entire ultrasonic vibration honing system's dynamics model is established.On the platform of UG NX7.0, the system's simplified model has been established. Then with the module of NX7.0 NASTRAN, the finite element modal analysis and the power response analysis have been carried on. The modal analysis obtains the ideal mode of vibration base frequency is 18.54 KHz, which is close to the actual 18.6 KHz. The power response analysis obtains the displacement cloud and the stress cloud, which confirmed the high frequency amplitude is bigger than 10 ?m.Based on the indentation fracture mechanics, Nd_Fe_B material removal mechanism has been discussed. Synthesizing the single abrasive dynamics model and the empirical formula, the supersonic honing processing Nd_Fe_B material removal model has been obtained.5.The analysis of surface roughness and the material removal quantity indicated that the ultrasonic vibration honing precision processing Nd_Fe_B material can obtain the lower surface roughness, simultaneously confirmed the material removal model to have the guiding significance to the practical work.The research result promulgated the grinding mechanism of ultrasonic vibration honing processing Nd_Fe_B material, consummated and developed the new technology of ultrasonic vibration honing processing hard crisp Nd_Fe_B material, which further promoted the Nd_Fe_B permanent-magnet material's project practical application.