As the displacement of the brush increases beyond the flexibility of the bush the magnetic bristles are able to break and reform further increasing the flexibility and versatility of this finishing process.
Specifically the selection of iron particles and abrasive particles dictates the minimum surface roughness that can be achieved. One key parameter that the user needs to be aware of is the proper completion of the magnetic circuit to ensure the magnetic flux uniformly permeates through the workpiece at the desired finishing location.
Close control of the surface texture and roughness can be manipulated through the selection of the right abrasive size and oscillation speed and spindle rpm.
The different MAF processes are listed in increasing surface roughness resolution while decreasing in applied force. Unlike a conventional brush the magnetic chains of particles are flexible and will conform around any geometry.
As the surface roughness decreases smaller abrasive particles are necessary to continue material removal.
The main difference between internal and external finishing operations is the location of the brush and the workpiece however the application of force is essentially the same hence the material removal mechanism is identical in both cases.
However it can also easily be applicable to internal finishing processes and is especially effective at finishing the internal surfaces of workpieces that are difficult Magnetic abrasive finishing access otherwise such as capillary tubes and other small gauge needles.
Over time the surface roughness of the workpiece surface reaches a minimum value, this is due to the physical limitations of the current finishing setup.
The addition of an oil based lubricant, the magnetic brush can also be considered a magnetorheological fluid. This process is repeated as the contact between the brush and the surface continues during the finishing operation. This is primarily due to the reduction in iron particle size from one type of finishing to the next.
The magnetic particle and abrasive mixture is commonly referred to the "magnetic brush" because it appears and behaves similar to a wire brush. Each type has its specific niche that it may fulfill better than its counterparts therefore knowing the application of the process is key to selecting the proper finishing operation.
Generally speaking the faster the motion of the brush the more dense the finishing marks on the surface and the higher the surface roughness. In order to alleviate these problems it is common practice to mix the magnetic particles with both large and smaller particles to "fill" the "holes" of the brush, the small particles effectively coat the larger particles within the particle chain.
Therefore, this specific variety of MAF is aimed towards finishing of the free form external surfaces such as airfoils or prosthesis.
The particle sizes for the magnetic particles in the brush dictate the finishing force which is governed by the magnetic force on a particle equation. Material removal[ edit ] The combination of tangential force and normal forces exerted by the brush onto the workpiece is theorized to remove material from the top peaks of the surface asperities.Magnetic Abrasive Finishing (MAF) Process Harry P.
Coats first patented MAF in Although US originate this idea, most of later period development is done by USSR + Bulgaria. CONCLUSION • Magnetic abrasive finishing process can be used for surface finishing as well as surface modification of hard to finish surfaces such as brass, stainless steel, etc.
• Magnetic abrasive finishing can be successfully used for finishing of internal as well as external surfaces of complicated design. Magnetic Abrasive Finishing (MAF) is the process which is capable of precision finishing of such work pieces.
Since MAF does not require direct contact with the tool, the particles can be introduced into areas which are hard to reach by conventional techniques. Magnetic abrasive finishing (MAF) is one of the advanced finishing processes, which produces a high level of surface quality and is primarily controlled by a magnetic field.
In MAF[1,3}, the work piece is kept between the two poles of a magnet. The working gap between the work piece and the magnet is filled. I am doing my Ph.D in Magnetic Abrasive Finishing. If any one knows the new research information of MAF please let me know. I'm a Masters student at IIT, Bombay completing my studies in the coming July.
I did my thesis on optimization of MAF process. I've carried out some experiments and collected. Magnetic Abrasive Finishing (MAF) is a process in which a mixture of non-ferromagnetic abrasives and ferromagnetic iron particles is used to do finishing operation with the aid of magnetic force.
The iron particles in the mixture are magnetically energized using a magnetic field.Download