End-Milling of CFRP/Ti-6Al-4V with Electroplated cBN Tool

Abstract

In recent years, the demand for carbon fiber reinforced plastics (CFRP), which have excellent mechanical properties, is increasing in various fields. In particular, the amount of CFRP used accounts for more than 50% of the body structure weight of the state-of-the-art airplanes. Moreover, in such airplanes, stack material, which is a combination of CFRP and titanium alloy (Ti-alloy), is frequently used. Therefore, a novel high-efficiency end-milling technology for cutting CFRP and Ti-alloy simultaneously is required. It is known that for restraining the occurrence of tool wear, diamond coating, which has high hardness, is useful. On the other hand, in the case of machining of Ti-alloy, several problems arise due to the machining heat. Consequently, in this study, we focus on cBN (cubic boron nitride). In order to compare diamond coating and cBN, end-mills, which were electroplated diamond grains, were also fabricated. In this study, as a cutting experiment, side milling of stack material, which is a combination of CFRP and Ti-6Al-4V, was carried out using the fabricated tools. Then, we discuss their cutting performance by measuring the CFRP temperature and chip temperature, tool wear, surface roughness, and surface integrity. As a result, it could be expected to precisely cut the stack material with the fabricated electroplated cBN end-mill. However, it is seen that improvement of the tool shape or the electrodeposition process is required.