Reducing the roughness of internal surface of an additive manufacturing produced 316 steel component by chempolishing and electropolishing

Abstract

Surface roughness of an as produced AM component is very high, which prohibits the direct utilization of additively manufactured (AM) components for the intended applications. Reducing surface roughness is exponentially more challenging for the internal surfaces of an AM component. This paper reports our research in the area of postprocessing of interior surfaces of an AM component. We have investigated electropolishing and chemical polishing (chempolishing) methods to reduce the surface roughness of the internal surface. We found that chempolishing was effective in simultaneously reducing the internal and external surface roughness of 316 steel AM components. Chempolishing is found suitable for any complicated AM shape and geometry. Our electropolishing methodology was effective in reducing the surface roughness of the internal or external surfaces provided that a counter electrode could be positioned in the proximity of the surface to be polished. We have performed optical profilometry, scanning electron microscopy, and contact angle measurement study to investigate the difference between electropolishing and chemical polishing methods.