ガラスビーズ強化ポリエステル樹脂切削時の工具摩耗

Abstract

In order to compare with the tool wear in cutting GFRP, the glass beads reinforced polyester resin was turned. Wear characteristics of many tool materials were studied, and both the abraded surfaces of cutting tools and the glass beads in cut surfaces were observed with SEM. The tool wear is the abrasive one. The wear resistances of tool materials are similar to that in cutting GFRP. In some cases, the wear increases steeply with increase of cutting speed over a certain critical cutting speed. This phenomenon is similar to that in cutting GFRP. This occurs at the feed rate of 0.10 mm/rev in P 10 and Co-rich cemented carbide tools of WC-Co grade. In this case, the abraded surface of the tool is very rough because of random falling off of carbide grains and the glass beads in a cut surface rub the abraded surface lightly, so they scarecely fracture at low cutting speed. The abraded surface is comparatively smooth and the glass beads rub the abraded surface severly in the neighbourhood of the critical cutting speed. The abraded surface becomes rough again and the glass beads rub the abraded surface more severely, so many beads fracture over the critical cutting speed. This phenomenon do not occur at the feed rate of 0.05 and 0.20 mm/rev. This phenomenon is caused by the mechanism that the falling off of carbide grains and the fracture of glass beads in the cut surface promote each other over the critical cutting speed. This mechanism is quite different from that of the similar phenomenon in cutting GFRP.