Experimental Investigations On Magnetic Abrasive Finishing

There are many long and thin tubes using in medical treatment,biochemistry,spaceflight and food making. It is required that these tubes have a very fine surface roughness. But the traditional processes can not do the effective machining for the specific characteristics of these tubes. In addition, fine surface finishing of some small workpieces is in high demand in many areas. Because it is very hard to fix them, the traditional processes also can not polish this surface. So it needs a new process to solve these problems.Magnetic abrasive finishing is a precise polishing method that the magnetic abrasive is the cutting tool, the abrasion pressure is controlled by a magnetic filed to produce a relative motion between the abrasives and the work surface. A limited amount of material will be removed to obtain the required surface. Owing to the magnetic field, the magnetic abrasives will become a flexible magnetic brush. When the cutting resistance is larger than magnetic force, the magnetic abrasives will roll and slide on the work surface. So this process can not do serious damage to the surface. Furthermore, the process doesn't need the strict precision of the equipment and the vibration nearly will not affect the surface quality. Because of these characteristic, magnetic abrasive finishing can do polishing for long tubes and small workpieces. In order to realize the mechanisms and practicability of magnetic abrasive finishing, the main work and achievements of this paper are listed as follow:(1)The finishing mechanisms of long tubes and small workpieces by magnetic abrasive finishing are investigated. Some investigations are done to analyze the forces exerted on magnetic abrasives and the movement of magnetic abrasive brush and the mechanism of the cutting.(2) In this paper, we design the experiments of magnetic abrasive finishing for inner surface. The abrasives are non-combined. The results demonstrate that the best surface roughness can be attained is 0.18μm. Then the experiments are researched to analyze the influences of reciprocating movement and the generation of electromagnetic field.(3)By the simulation of inner surface finishing using Matlab, the effects of the main parameters on the quality of the process are analyzed. The conclusions can be consulted by the practical experiments.(4)The finishing experiment device for small workpiece is developed. Some experiments are done to research its performance. Experimental results demonstrate that the performance of this method is good, we can attain the roughness of 0.15μm.