| 摘要 |
PURPOSE:To produce a silicon nitride-based sintered compact excellent in creep resistance and having high strength in the temp. range from room temp. to a high temp. and to impart high reliability in the case of application to automotive parts or parts for a gas engine used at a high temp. CONSTITUTION:This silicon nitride-based sintered compact excellent in creep resistance contains >=70mol% silicon nitride, 1-10mol% (expressed in terms of oxides) group IIIa elements of the Periodic Table and 1-20mol% (expressed in terms of SiO2) impurity-like oxygen. The group IIIa elements include Lu as a base and the amt. of group IIIa elements other than Lu is <=7mol% of the amt. of all the group IIIa elements. The molar ratio of the amt. (expressed in terms of SiO2) of the oxygen to the amt. (expressed in terms of oxides) of all the group IIIa elements is <2. |
