Damage‐Enhanced Creep in a Siliconized Silicon Carbide: Phenomenology
Damage‐Enhanced Creep in a Siliconized Silicon Carbide: Phenomenology
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硅化碳化硅中的损伤增强蠕变：现象学
DOI：
10.1111/j.1151-2916.1988.tb05926.x
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发表时间：
1988
影响因子：
3.9
通讯作者：
L. Chuck
中科院分区：
文献类型：
--
作者：
S. Wiederhorn;D. E. Roberts;T. Chuang;L. Chuck
商业级反应粘结碳化硅的蠕变行为在 1300°C 的温度下进行了表征。拉伸时比压缩时更容易发生蠕变。在给定的施加应力下，拉伸稳态蠕变速率至少是压缩稳态蠕变速率的 20 倍。在拉伸和压缩情况下，稳态蠕变的应力指数随着施加应力的增加而增加。在低施加应力下，应力指数为~4，表明在两相复合材料中存在某种位错机制。在高应力下，拉伸时的应力指数约为 11。应力指数的增加归因于空腔形式的损伤累积。建议空化的有效阈值应力小于 100 MPa。在压缩过程中，应力指数随应力增加的原因不能归因于空化现象。
The creep behavior of a commercial grade of reaction-bonded silicon carbide was characterized at a temperature of 1300°C. Creep occurred more easily in tension than in compression. At a given applied stress, the steady-state creep rate in tension was found to be at least 20 times that obtained in compression. In both tension and compression, the stress exponent for steadystate creep was found to increase with increasing applied stresses. At low applied stresses, the stress exponent was ∼4, suggesting some kind of dislocation mechanism operating in the two-phase composite. At high stresses, the stress exponent was ∼11 in tension. The increase in the stress exponent was attributed to damage accumulation in the form of cavities. An effective threshold stress for cavitation of less than 100 MPa was suggested. In compression, the cause of the increase of stress exponent with stress cannot be attributed to cavitation.