Mirror-Like Finishing of Soft Materials Using a Polishing Tool with Controllable Hardness by Heat Softening

Abstract

The polishing process is one of the traditional finishing process for improvement of geometrical tolerance and surface roughness. Most of polishing processes are conducted by skilled worker as a manual process at present. The productivity of this process is very lower than other mechanized processes and is difficult to be controlled. An automated polishing system and optimized slurry for this system were developed from these reasons. In the case of the polishing to soft material such as plastics, variation of the grain size and the shape strongly effect to finished surface roughness. Hence, many scratches are easily occurred on the surface of the workpiece. We focused on the relationship of the Vickers hardness between workpiece and the polishing head for the machining of them. When the Vickers hardness of the tool head takes less than 20% of the workpiece, the finished surface roughness become good because of uniform cutting depth of grains on the workpiece. A polishing tool which can control the hardness of the head surface by heat softening was developed. The thermoplastic resin is used as material of the head and optimum polishing pressure was cleared. Several soft materials were machined as 0.16μmRz using the developed tool. It is concluded from the result that; (1)The suitable hardness of the tool head is less than 20% of the workpiece for uniform cutting depth of the grains. (2)A new polishing tool with controllable its surface hardness was developed. (3)By the developed tool, soft materials can be finished as mirror-like surface.

An Investigation of Lapping Characteristics for Mirror-Like Finish Using a Lathe with Linear Motor

“…From the results, the surface roughness Rz lower than 0.1µm Before lapping rocess After lapping is possible when the hardness ratio of lapping head to work surface is lower than 20 percent. This result also agreed with the simulation study in other research [6].…”

Research on oxidation phenomenon during titanium machining and its prevention

“…In this regard, titanium with additional characteristics, such as: high strength, heat resistance, low thermal conductivity, light weight and biocompatibility are frequently being used. In the same way, the latest industrial applications require the use of grinding and polishing processes to achieve a mirror-like surface finishing [4][5][6]. Nevertheless, machining titanium products presents a significant challenge, given that titanium tends to oxidize.…”