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Magnetic Abrasive Finishing of Additively Manufactured Components 

Dr. Hitomi Yamaguchi, Associate Professor, University of Florida, USA

Additive manufacturing (AM) technologies have broken out of the traditional manufacturing paradigm, especially the manufacturing of complex components in small batches. Selective laser melting (SLM) is one of the most versatile AM processes. Components made using SLM have applications in a wide variety of industrial areas including aerospace, biomedical engineering, etc. However, the powder-consolidation mechanism in SLM influences the mechanical properties, surface morphology, and surface integrity (e.g., hardness and residual stress) of components and the corresponding product functions. Therefore, choices of post-SLM processes, such as heat treatment and surface finishing processes, plays an important role in minimizing these defects and maximizing the component performance. 

A manufacturing technology called Magnetic Abrasive Finishing (MAF) has been applied for surface finishing of SLM-produced 316L stainless steel components. In MAF, ferrous particles are suspended by magnetic force and link together along the lines of magnetic flux in a magnetic field. The ferrous particle chains, connected by magnetic force, enable a flexible configuration. This unique behavior of the ferrous particles allows the application of the finishing operation not only to easily accessible surfaces but also to areas that are hard to reach by conventional mechanical techniques, such as freeform components (e.g., knee prostheses), the interiors of capillary tubes (e.g., needles), and flexible tubes (e.g., catheter shafts). This presentation describes the surface characteristics of SLM-produced 316L stainless steel parts. Secondly, the fundamentals of MAF and the effects of MAF on the surface roughness, surface texture, tribological properties, and residual stress of SLM-produced parts will be demonstrated. This presentation will also include some on-going research at the University of Florida related to the use of MAF on additively manufactured components.