Reducing the Roughness of Internal Surface of an Additive Manufacturing Produced Steel Component by Chempolishing and Electropolishing

Reducing the surface roughness of an additively manufactured (AM) component is one of the most critical factors in determining the suitability of an AM component. As produced surface roughness of an AM component is very high. This prohibits the direct utilization of AM components for the intended applications. For most of the engineering applications, surface roughness must be reduced significantly. Reducing surface roughness is exponentially more challenging for the internal surfaces of a component. This paper reports research in the area of post processing interior surfaces of an AM component. Electropolishing and chemical polishing (chempolishing) methods were applied to reduce the surface roughness of the internal surface. It was found that chempolishing was very effective in simultaneously reducing the internal and external surface roughness of steel AM components for any complicated AM shape and geometry. The electropolishing methodology employed was very effective in reducing the surface roughness of the internal or external surfaces as long as a counter electrode could be positioned in the proximity of the surface to be polished. However, electropolishing produced better performance on the outer surfaces as compared to chempolishing. This paper summarizes research efforts to tackle the critical issue of reducing the surface roughness of complex AM components.