Hiroo Shizuka

The Effect of Cutting Edge Sharpness on Cutting Characteristic of Polycarbonate

Polycarbonate is used in various fields because it exhibits high-impact resistance and light-weight properties. Products requiring high flatness are made using an end mill. When the cutting edge of an end mill becomes dull, the surface quality worsens. This is a serious problem. In this experiment, sharp and worn tools were prepared to investigate the effects of an edge’s sharpness on the cutting characteristics of polycarbonate. The cutting force was measured, and the finished surface was observed. When the sharpness of the cutting edge was changed from 1 to 12 μm, the cutting force increased 20 % and the quality of the finished surface greatly worsens. In conclusion, small wear of a cutting edge, e.g. within 11 μm, degrades a surface’s finish and transparency.

The Assist Effect of Nitrogen Atmosphere on MQL Cutting Performance

This paper investigates the effects of using nitrogen gas on Mist cutting. In this study we tried to improve the cooling effect of mist on cutting by using N2 gas to assist cooling. As a result, tool breakage was prevented when using carbide tools and a large reduction in tool wear was confirmed when using cermet tools. Our conclusion is that N2 gas assisted mist cutting reduces oxidation wear, which means that the cutting characteristics are better than in conventional mist cutting.

Study on Cutting Characteristics under a Nitrogen Atmosphere

In the existing circumstances, a lot of oil is used in the cutting process and almost all oil is finally incinerated. One of the problem is that dioxin may be produced when the oil is incinerated. Therefore, we have to make a new cutting process to reduce these oils. A ideal solution to this problem is dry cutting, but the tool life is probably shortened because of the lack of cooling factor. Without the cooling factor, tool temperature increases significantly. About this heat process, we can surmise that, there are two factors in it. One of the factors is frictional heat between tools and work, and the other factor is generation of heat by oxidation. Then, the cutting in nitrogen gas can control the generation of heat by oxidation and increase the tool life. However in nitrogen cutting, higher, the concentration of nitrogen, more, the adhesion occurs. In this study, we tried to solve the adhesive problems by changing the cutting condition and tool materials. As a result, we can increase tool life such that high speed dry cutting is possible, which has been infeasible. Furthermore, Nitrogen cutting has the possibility that oxygen concentration changes the cutting characteristics by the lubricating effect of metal oxide film. In this study, we also turned our attention to that and examine the concern with nitrogen concentration.