IMPURITY-ENHANCED INTERGRANULAR CAVITY FORMATION IN SILICON-NITRIDE AT HIGH-TEMPERATURES

被引：50

作者：

TANAKA, I

PEZZOTTI, G

MATSUSHITA, K

MIYAMOTO, Y

OKAMOTO, T

机构：

[1] Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka

来源：

JOURNAL OF THE AMERICAN CERAMIC SOCIETY | 1991年 / 74卷 / 04期

关键词：

SILICON NITRIDE; MECHANICAL PROPERTIES; FRICTION; CRACK GROWTH; IMPURITIES;

D O I：

10.1111/j.1151-2916.1991.tb06920.x

中图分类号：

TQ174 [陶瓷工业]; TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

The effect of trace impurities on high-temperature strength is examined in Si3N4 sintered without additives. Strength degradation above 1000-degrees-C occurs only in the low-purity material, which also exhibits an intergranular slow crack growth (SCG) rate 2 orders of magnitude faster than that of the high-purity material at 1400-degrees-C. A relaxation peak of internal friction is observed only in the low-purity material, at almost-equal-to 1200-degrees-C, and the origin of this peak is ascribed to the initial stage of SCG-that is, the cavity-nucleation stage, enhanced by impurities. Based on the present results, a model for impurity-enhanced SCG is proposed.

引用

页码：752 / 759

页数：8

共 23 条

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