This paper describes the development of a movable manual electromagnet with an adjustable flux density to improve the inner surface smoothness of a cone pipe using a magnetic abrasive finishing process. This method is fabricated to reduce further the roughness of the internal surface of the conic shape, which was modeled as an electromagnet oscillating in the work zone with a ball roller. Statistically significant improvement in the process was achieved using unbounded magnetic abrasive, light oil, flux density, controlled feed rate, and constant rotational speed in the experiment. The ball transfer equipped on the top of the electromagnet pole plays an essential role in spinning over the outer cone pipe during the experiment and helps reduce friction while the workpiece fluctuates. Furthermore, the flux density can be changed to control the magnetic force and select the most acceptable option. In addition, a procedure for finishing has been designed for finishing a cone pipe, and we sought to understand how the flux density affects the material in removal exterior roughness. As a result, the flux density is clarified, and a higher flux density achieves excellent removal of surface roughness of the inner deformed pipe from 1.68 μm to 0.39 μm within 24 min.

The orthopedic stent wire is one of the critical medical components, which is mainly used for the replacement of physically damaged parts in the human body. Therefore, a smooth surface and lack of toxic substances on the surface of this component are highly demanded. In this study, a magnetic abrasive finishing (MAF) process was carried out using a non-toxic abrasive compound (a mixture of iron powder, diamond particles, cold cream, and eco-friendly oils) to achieve high-quality surface finishing of orthopedic stent wire. The surface roughness (Ra) of the stent wire was investigated according to various processing parameters: different rotational speeds (500, 1000, and 2000 rpm), diamond particle sizes (1.0 µm), and three eco-friendly oils (olive oil: C98H184O10; grapeseed oil: C18H32O2; and castor oil: C57H104O9) within 300 s of the finishing time. The results showed that the surface roughness of the wire was reduced to 0.04 µm with a rotation speed of 1000 rpm and a diamond particle size of 1 µm when using grapeseed oil. SEM microimages and EDS analysis showed that the MAF process using a non-toxic abrasive compound could improve the surface quality of orthopedic Ni-Ti stent wire with a lack of toxic substances on the surface finish.

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