Proposal for Surface Smoothing of Additive Manufactured Cooling Channel with Electrochemical Machining and Basic Research on Its Application to Straight Holes

Abstract

Additive manufacturing has been used to fabricate molds with intricately curved cooling channels, because it is easy to fabricate complex shapes. However, there is a problem that the surface of cooling channels fabricated by additive manufacturing is relatively rough. Therefore, it is necessary to reduce the surface roughness of the cooling channels. Because conventional smoothing methods usually require a rotating tool, they are unsuitable for handling channels with complex shapes. In this study, the authors proposed the use of electrochemical machining (ECM) to realize surface smoothing because it does not require rotating tools to smooth the channel surface. We designed and fabricated a tool electrode unit with a disk-shaped electrode sandwiched between insulating hemispheres that can move freely along complex channels. The movement and smoothing characteristics of the developed tool-electrode unit were investigated experimentally. It was found the tool unit could move freely through a curved channel, and the surface roughness was decreased by scanning the ECM tool unit through a straight channel. Furthermore, it was found that the larger the machining amount, the better is the surface roughness.