To provide a silicon nitride sintered compact where wear resistance and chipping resistance are improved, a cutting tool, a device for cutting works and a cutting method.
The silicon nitride sintered compact has a crystal phase being mainly silicon nitride crystals and an amorphous grain boundary phase containing lanthanum, aluminum, magnesium, silicon and oxygen and existing in the grain boundary of the silicon nitride crystals. The content of magnesium in a face at a depth of 0.3 mm from the surface of the sintered compact is 1.3 mass% or less in terms of an oxide. The content of magnesium in a face at a depth of 0.3 mm from the surface of the sintered compact is less than that in a face at a depth of 1 mm from the surface of the sintered compact. The difference of the content of magnesium between in a face at a depth of 0.3 mm and in a face at a depth of 1 mm from the surface of the sintered compact is 0.5 mass% or less in terms of an oxide.
TATENO SHUICHI
YOSHIMITSU HIROSHI
WATANABE TAKASHI
NAKAOKA TATSUYUKI
| JPH046159A | 1992-01-10 | |||
| JP2000351673A | 2000-12-19 | |||
| JP2002012474A | 2002-01-15 |