Magnetic abrasive finishing technology has been known very well in finishing of stainless steel SUS304 pipes to mirror finish standard. However, the applications in softer metal such as aluminum A2017 were difficult due to soft metal characteristic itself. In 2002, Zou and Shinmura had developed a new method of magnetic field assisted machining process using magnetic machining jig for SUS304 pipe [. The development has since then expanded in many research. This research finds the optimum finishing condition for mirror finish standard in internal surface of aluminum A2017 pipe. We use a 100% polyester fabric that does not cause scratch on the material and found that the optimum pole-pipe gap to be 13mm to achieve the best surface roughness Ra of 0.020μm after finishing, from surface roughness Ra of 0.195μm before finishing.

Abstract:The research proposes a new internal surface magnetic abrasive finishing (MAF) process, which compounded with electrochemical machining (ECM) to decrease machining time. The electrochemical process changes the morphology of the aluminum tube internal surface, producing an oxidation film. Then, we removed the film by magnetic abrasive finishing, results in minimized surface roughness in a significantly reduced processing time when compared to the conventional MAF. In this research, a new experimental set up with a tool that capable of magnetic abrasive finishing and electrochemical finishing was designed and developed to study the machining feasibility. The newly developed finishing method demonstrated simultaneous process of aluminum oxide film formation by ECM and its removal by MAF. This process plays a significant role in preventing the deepening of the pit during ECM and speed up the planarization. The method was developed step by step; firstly, ECM and MAF were conducted in two separate processes. In the second experiment, we modified the finishing conditions to facilitate one-stage finishing method. An investigation of the finishing surface is focusing on the pit size that formed by ECM. The pit size indicated the residue of oxide film because it is a part of the oxidation film construction. Pits morphology changes were observed for certain finishing time to determine the minimum finishing time for its removal. Surface roughness and SEM photograph of the finishing surface were recorded and studied.