NITROGEN-CONTAINING CERMET

摘要

A cermet drill consisting of cermet composed of a hard dispersed phase and a combined metal phase is disclosed. The hard dispersed phase contains a titanium-containing metal atom group and a nitrogen-containing nonmetal atom group. The quantity of the titanium in the metal atom group ranges from 0.5 to 0.95 (both inclusive, the same applies hereinbelow) in terms of an atomic ratio. The quantity of the nitrogen in the nonmetal atom group ranges from 0.1 to 0.7 in terms of atomic ratio. The hard dispersed phase has a minute particle group of an average particle diameter of from 0.2 to 0.6 mu m and a coarse particle group of an average particle diameter of from 1 to 3 mu m. The volume ratio of the minute particle group to the coarse particle group ranges from 0.3 to 3. The weight percentage of the combined metal phase in the cermet ranges from 5 to 30. This cermet drill exhibits a high abrasion resistance, a high tenacity and a high thermal cracking resistance.