抄録
In order to expand the applications of CFRP in aircraft and/or automobile industries, high quality holes must be created on CFRP parts efficiently. However, it is difficult for conventional methods such as drilling and helical milling to meet the requirements, and hence a so-called tilt helical milling (THM) method has been proposed which is performed just by tilting the workpiece at a small angle in helical milling. This method combined advantages of both helical milling and drilling to achieve high-quality and delamination-free holes. As a step towards the development of this technology, the hole formation process in THM was analyzed. It was found that in THM, the bottom section of the hole was W-shape and a V-groove was created under the end face of the tool, which was conducive to exclude chips and keep cool. Compared to the conventional helical milling (CHM), the sectional areas of the removed materials in THM seemed smaller in both entry and exit sides of the hole, delamination at both entry and exit sides of the hole had been prevented, and significant reduction in cutting force had been achieved.
