Laminar Ceramics That Exhibit a Threshold Strength.
Laminar Ceramics That Exhibit a Threshold Strength.
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DOI：
10.1126/science.286.5437.102
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发表时间：
1999-10
期刊：
影响因子：
56.9
通讯作者：
M. P. Rao;A. Sanchez-Herencia;G. Beltz;R. McMeeking;F. Lange
中科院分区：
文献类型：
--
作者：
M. P. Rao;A. Sanchez-Herencia;G. Beltz;R. McMeeking;F. Lange
层状陶瓷内的薄压缩层阻止大裂纹（表面和内部）并产生阈值强度。这种现象增加了陶瓷的损伤容限，并将使工程师能够为结构应用设计可靠的陶瓷部件。应力强度因子的推导表明，裂纹夹在两个压缩层之间的阈值强度是成正比的残余压应力和压缩层的厚度，并成反比的压缩层之间的距离。由厚氧化铝层（605 +/-11微米）和薄莫来石/氧化铝压缩层（37 +/-1.4微米）组成的层压制品具有482 +/-20兆帕的阈值强度，与理论相当一致。
Thin compressive layers within a laminar ceramic arrest large cracks (surface and internal) and produce a threshold strength. This phenomenon increases the damage tolerance of ceramics and will allow engineers to design reliable ceramic components for structural applications. The stress intensity factor derived for a crack sandwiched between two compressive layers suggests that the threshold strength is proportional to the residual compressive stress and the thickness of the compressive layer and is inversely proportional to the distance between the compressive layers. Laminates composed of thick alumina layers (605 +/- 11 micrometers) and thin mullite/alumina compressive layers (37 +/- 1.4 micrometers) fabricated for this study had a threshold strength of 482 +/- 20 megapascals, in fair agreement with the theory.