2021 Volume 65 Issue 1 Pages 30-35
A means of hardening TiB2 base films by controlling oxygen content was developed to improve cutting efficiency of tools against difficult-to-machine materials, such as Ti alloy. By increasing the B/Ti ratio in the films above 2, oxidation of Ti during the film formation process was suppressed and the hardness was increased. The greatest hardness of 35 GPa was obtained in the film with the lowest oxygen content of 3 at% in this study by producing a film with a base pressure of 4 ×10-4 Pa. The frictional properties of the films were improved by adding C. The coated tools showed excellent cutting performance against Ti alloy. The chip formation process became smooth and the cutting force decreased by using the coated tools.
