In order to clarify the wear resistance as cutting tools, the relationship between oxygen addition and cutting performances of the β-Si3N4 ceramics with 5 mass% Y2O3 and 2 or 4 mass% Al2O3 was investigated. From test results, we could conclude that the mechanical properties of β-Si3N4 ceramics depending on oxygen introduction are effective on cutting performance improvements of β-Si3N4 ceramics.

* Department of Materials Science and Engineering, Faculty of Engineering, Nagasaki University