Study On Ball Milling Preparation Technology And Finishing Experiment Of Fe/Al₂O₃Magnetic Abrasive

The subject is supported by the National Natural Science Fund project (51175365)" study on characteristics and index system of magnetic abrasive on magnetic abrasive finishing". The project is mainly to explore the method and the preparation process of magnetic abrasive, and study the finishing performance of magnetic abrasive and establish the comprehensive evaluation system of magnetic abrasive.Surface quality of the parts has a lot to do with the using performance, reliability and service of the parts, and also has a big impact on the life of the whole of the product, so improving surface quality of the parts is of great significance. The magnetic abrasive finishing technology as a new technology of surface finishing, its development and popularization will have an impellent function to promote finishing quality of the parts. However, the magnetic abrasive as grinding apparatus of this finishing technology, its performance has a crucial function to surface quality of the finishing parts.At present, preparations of the magnetic abrasive methods are not able to meet the needs of this technology development. Various preparation methods have its advantages and disadvantages, and are not able to make magnetic abrasive finishing technology used widely in the actual industrial production. This paper first starts from the mechanism of magnetic abrasive processing, in-depth studies magnetic abrasive development states in order to have an in-depth understanding of the performance and composition of magnetic abrasive, so contributing to the development of the new preparation technology of magnetic abrasive.A new process of preparing Fe/Al2O3magnetic abrasive by high energy ball milling is submitted in this thesis. The microstructure size of magnetic abrasive under different milling times were analyzed and examined by X-ray diffraction and SEM. The size variations under different milling times were analyzed by granularity instrument. By analyzing the kinetics of rolling ball milling, the forcing and movement of the grinding balls and the impact behavior between milling balls is investigated in the process, and theoretical relationships between the technical parameters of ball milling (angular velocity of ball milling, ball to powder ratio, radius of milling ball) and ball speed and the collision frequency are established in this thesis. From the process of stress and deformation of powder, the relationships between stress of powder, height and volume captured, broken, cold welding and milling process parameters are established. The results show that the magnetic abrasive prepared by ball milling have small particle, good performance, even organizations, the short preparation period and low cost, and is benefit to make large-scale production. Through the processing experiments using the Fe/Al2O3magnetic abrasive prepared by ball milling to45steel, it determines the motion, process and equipment parameters, which affects magnetic abrasive finishing. Based on the determined parameters, we continued to use magnetic abrasive to do machining experiment so as to determine the factors influencing the process of preparation of magnetic abrasive. Finally, we further conclude the preparation parameters of excellent performance of magnetic abrasive.