ラジアス工具を用いた高炭素含有型コバルトクロム合金の高速ミーリング加工に関する研究（工具材種と切削速度の違いが切削性能に及ぼす影響）

抄録

In recent years, the proportion of elderly individuals in Japan has been increasing, accompanied by a rise in the number of patients with osteoarthritis. In particular, artificial joints, which are effective in treating knee osteoarthritis, commonly use Co-Cr-Mo alloys (CCM alloys) for their sliding surfaces due to their ability to suppress uneven wear. However, conventional CCM alloys pose a problem during sliding use, as they generate biotoxic metallic wear debris. To address this, high-carbon Co-Cr-Mo alloys (HC-CCM alloys) with improved wear resistance have been developed. Nevertheless, there have been few studies on the machining of HC-CCM alloy with end mills. This study investigates the high-speed machining of HC-CCM alloy using radius end mills, focusing on the influence of tool material and cutting speed on cutting performance. The results showed that both carbide and CBN tools reached their tool life limit within a short cutting length. In contrast, the binderless nano-polycrystalline cubic boron nitride (RcBN) tool exhibited excellent wear resistance, achieving a machining length of up to 7.0 km. These findings indicate that the RcBN tool is highly effective for machining HC-CCM alloy. Furthermore, excessive tool damage was observed at cutting speeds exceeding 15 m/s, suggesting that an optimal cutting speed is approximately 10 m/s.