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In this research the Magnetic Abrasive Finishing capabilities in AISI 4140 steel polishing was studied. Surface roughness was considered as a function of the tool rotational speed, working gap, abrasive material and abrasives particle mesh size. To conduct the tests, a specific magnetic tool was designed to polish the flat steel surfaces by a milling machine. Experiments were arranged based on Taguchi method and using abrasive material consisting of Aluminum Oxide or Silicon Carbide with paraffin oil and Carbonyl Iron powders with different mesh sizes. After surface roughness measurement of samples, the effect of each parameter on the surface quality was inspected by ANOVA method. Results showed that in Magnetic Abrasive Finishing of mentioned steel, the parameters of working gap, tool rotational speed and the abrasive material type are of the most importance as ordered. Finally, a roughness predictor function was introduced by regression method.

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The attempts of researchers in industries to obtain accurate and high quality surfaces led to the invention of new methods of finishing. Magnetic abrasive finishing (MAF) is a relatively new type of finishing in which the magnetic field is used to control the abrasive tools. Applications such as the surface of molds are ones of the parts which require very high surface smoothness. Usually this type of parts has freeform. In this study, the effect of magnetic abrasive process parameters on freeform surfaces of parts made of aluminum is examined. This method is obtained through combination of magnetic abrasive process and Control Numerical Computer (CNC). The use of simple hemisphere for installation on the flat area of the magnets as well as magnets’ spark in curve form is a measure done during testing the experiments. The design of experiments is based on response surface methodology. The gap, the rotational speed of the spindle and the feed rate are found influential and regression equations governing the process are also determined. The impact of intensity of the magnetic field is obtained using the finite element software of Maxwell. Results show that in concave areas of the surface, generally speaking, the surface roughness decreases to 0.2 µm from its original 1.3 µm roughness. However, in some points the lowest surface roughness of 0.08 µm was measured

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Ultrasonic Assisted Magnetic Abrasive Finishing (UAMAF) is the combination of magnetic abrasive finishing (MAF) and ultrasonic vibrations to finish the surfaces in nanometer scale. In this work, the experimental setup for UAMAF was prepared to finish inner surface of tube workpiec. By using experimental setup, the effect of experimental parameters such as ultrasonic vibrations, mesh number, the type of abrasives (SiC and diamond) and finishing time has been investigated on the changes in the surface roughness of AL6061 tube workpiece. The experimental results showed that the use of ultrasonic vibrations has a significant effect on reducing the surface roughness. The changes in surface roughness increases with the mesh number from 90 to 800 and finishing time from 30s to 5 min. Among two types of abrasives, diamond showed the best performance in finishing. Optical microscopy images showed that the dominant finishing mechanism in MAF for coarse grains (with mesh size of 90 and 120) is two body and for fine grains (with mesh size of 220, 400 and 800) is three body. In UAMAF for both of the coarse and fine grains the dominant finishing mechanism is three body.

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Magnetic abrasive finishing process (MAF) is one of the latest advanced machining processes. After eight decades have passed since the registration of the magnetic abrasive polishing process, the applicability of this method has been proven in finishing all kinds of surfaces, including flat, cylindrical and free surfaces. In this research, the influence of MAF process movement parameters on the concave surface of cold-worked steel has been investigated experimentally using the response surface method. These parameters include rotational speed, linear speed, gap between abrasive brush and workpiece, magnetic flux density and curvature angle. For this purpose, a spherical head magnet is used and the powder used is prepared by mechanical alloying method. Cold-worked steel is used in the manufacture of roll forming molds, which is used in air engines to shape compressor and turbine blades, and also to investigate the feasibility of the MAF process on the workpiece surface with high hardness and yield stress, such as Cold work steel is selected. According to the results, the optimal value of the magnetic flux density is 0.55 tesla, and with the increase of the distance between the abrasive brush and the workpiece, the surface roughness changes initially increase and decrease after passing the optimal value.
 

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One of the components of the MAF process is the magnetic field that is applied through the field source. This source can be permanent or electrical. In terms of shape, permanent magnets are divided into two main categories: cubic and cylindrical. In the past researches, cylindrical overhead magnets have been used to perform MAF on free surfaces, which is not very efficient due to the time-consuming process. In this research, first of all, the methods of making overhead magnets have been examined to find the optimal magnetic conditions. Then, in order to increase the efficiency of the process, methods to increase the efficiency of the overhead magnet have been investigated. Based on this, the mentioned methods have been discussed and evaluated. According to the results, in the method of using a ball magnet and connecting it to a cylindrical magnet, the magnetism density is significant, and also by grooving the head magnet, the roughness changes on the inclined surfaces of the ferromagnetic workpiece from 21% to It reached 34.4% and in the inclined area with a curvature angle of 90 and 105 degrees of the surface of the ferromagnetic workpiece, a 9% increase in roughness changes occurs.