Study On The Preparation And Polishing Performance Of Bonded Magnetic Abrasive

Magnetic Abrasive Finishing (MAF) is a new kind finishing method by the magnetic field acting on magnetic abrasives. In the process of lapping, the magnetic abrasives between tool and machining surface are flexible and can be controlled easily. Due to its advantages, this method has been successfully used to finish the mould curved surface, inner surface of stainless-steel air bottle etc. In view of the wear of magnetic abrasives, they should be refreshed necessarily and frequently. So, the abrasives with better performance and lower price have been one key factor to determine the machining effect. Although much research has been done on MAF, magnetic abrasive has not been commercialized yet so far, which greatly restricts the development of MAF. Aiming to solve above problem, we investigated the development of magnetic abrasive and its machining performance.Firstly, by analyzing the methods of making magnetic abrasives, for the sake of low cost and easy production, binding method was chosen as the research method to make magnetic abrasive. According to the performance requests of magnetic abrasive, binding principle and the process of binding, one technological process of mixing, binding, pressing, crushing and filtering was drew out. Then, Fe+Al₂O₃ and Fe+SiC bonded magnetic abrasives were made respectively. Finally, the experiments were constructed to compare the polishing effect of the above abrasives. The results indicate that both abrasives have fine machining performances. However, Fe+Al₂O₃ abrasives are better than Fe+SiC ones on the aspect of improving surface roughness and duration. And the surfaces with Ra0.1μm around can be obtained.On the other hand, in order to improve the surface quality and shape precision of mould curved surface, NC magnetic abrasive finishing method of 2D curved surface was presented based on the honing principle. Then, simple polishing tool with permanent magnets embedding in the tool body and CNC machining program soft was also designed. The experiment results present the fine polishing effect with this method. This study is expected to be helpful to improve the efficiency of finishing process, reduce worker's labor intensity, realize the effective control of finishing process and obtain fine quality of workpiece surface.