| 摘要 |
PURPOSE:To enable cutting of steel and practical use as a slow-away tip with a breaker by specifying composition of Al2O3 and ZrO2 containing yttrium oxide components in an Al2O3-ZrO2-based sintered body. CONSTITUTION:The subject ceramics sintered body for cutting tools is composed of 32-48wt.% ZrO2 containing 1-5mol% Y2O3 as a stabilizer and the rest of Al2O3. As the above-mentioned stabilizer one or more of oxides of Mg, Ca, Ce, Nd, etc., may be used in 0.1-2mol% of the above-mentioned amount instead of Y2O3. In the sintered body the stability of ZrO2 is insufficient in <1mol% stabilizer and defect resistance thereof is reduced in >5mol% because of excessive hexagonal ZrO2. The defect resistance is reduced in 32wt.% ZrO2 and defect is caused in >48wt.% due to lowering of wear and thermal shock resistance. In those cases, the service life is short. |
