Impact of Variable Process Parameters of Magnetic Abrasive Finishing on Surface finish of mild Steel Using a DC current for Electromagnets

Fine finishing or finishing is the generally last process of the production of jobs that demand utmost quality with regard to shape, precision, and surface integrity. Fine finishing is a process that improves the surface of the jobs, enhancing its functional and excellence aspects. The major manufacturing sectors requires accurate finishing to enhance the appearance, performance, and durability of its components. Mild steel is generally utilized in the production of various components required in automotive and other applications. Conventional finishing and fine finishing methods can be challenging to apply when manufacturing components of varied shapes and sizes. To address this, unconventional fine finishing and finishing techniques are being employed. One typical method is magnetic abrasive finishing (MAF), a finishing technique that produces components of outstanding quality. In this method a cutting tool is the flexible magnetic abrasive brush (FMAB), guided by a DC magnetic field, to achieve the preferred surface finish. Typically, the magnetic abrasives used in MAF consist of key components like DC electromagnetic field, mixture of ferromagnetic powder and abrasives powder. In this study, mild steel bars undergo fine polishing using a MAF technique, with varying process parameters being examined. Aluminum oxide (Al2O3) serves as the abrasive, while a hemisphere pole shaped DC electromagnet is employed for the fine-finishing process. The process key variables, including magnetic flux density, workpiece rotational speed, and the percentage of abrasives with ferrous powder in the mixer, can be adjusted to achieve best surface finishes. The efficiency of the process is influenced by factors such as the abrasive particles content in the mixing ratio, the speed of the workpiece, and the input DC voltage that regulates the magnetic flux density. The results indicate that increasing the rotation speed and DC voltage enhances the surface finish of the mild steel rods. Specifically, experiments reveal that improvements in rotation speed and DC voltage can lead to a 47% increase in the maximum enrichment of surface roughness.