Abstract
Here, we propose a method of internal polishing for circular pipes by changing the slurry flow of a steel ball to serve as a weir in the circular inner surface. This processing method draws the steel ball into the circular pipe, with a magnet outside the pipe to control its movement. The slurry is designed to collide with the circular inner surface as it passes through the gap between the steel ball and the circular pipe to polish the circular inner surface by applying a spiral motion. Equipment using this principle was tested and shown to perform better than a simple slurry flow. First, a circular acrylic fiber pipe with a small initial surface roughness was used as a working material, and the polishing ability of the proposed technique was evaluated by a simple method. Commercial acrylic pipe with surface roughness of 0.01 μmRa after 60 minutes of polishing was gradually roughened to 0.24 μmRa. In contrast, without the steel ball, the surface roughness hardly changed and remained about 0.02 μmRa. Next, polishing was performed for metal with an initial surface roughness of 0.82 μmRa, and the results indicated that a smooth surface of 0.28 μmRa was obtained.
