Fracture of polycrystalline ceramics
Fracture of polycrystalline ceramics
复制标题
多晶陶瓷的断裂
DOI：
10.1007/978-94-011-6827-4_4
复制
发表时间：
1990
期刊：
影响因子：
--
通讯作者：
P. Swanson
中科院分区：
文献类型：
--
作者：
S. Freiman;P. Swanson
多晶陶瓷中的灾难性失效是由于应力裂纹扩展到临界尺寸而导致的，该临界尺寸可以跨越一系列尺寸尺度。当临界缺陷尺寸从小于特征微结构尺寸的尺度增加到包含许多颗粒直径的尺寸时，在某些多晶体中，抗断裂性增加5-10倍。这种增加代表了多晶体的抗断裂性与其单个组成单晶的抗断裂性之间的差异。在本章中，我们：（1）显示了晶粒尺寸和形状的相对较小的变化如何影响断裂韧性-裂纹尺寸关系（2）简要回顾了几种认为是多晶体断裂能高和断裂阻力随裂纹扩展而增加的微观结构机制;（3）给出亚临界扩展裂纹的原位显微观察结果，支持裂纹界面牵引是一种重要的断裂阻力机制;以及（4）检查牵引机制对预测在应力增强化学反应影响下扩展的缺陷的时间依赖性失效的复杂影响。
Catastrophic failure in polycrystalline ceramics results from stressed cracks growing to critical dimensions which can span a range of size scales. As critical flaw dimensions increase in size from a scale less than characteristic micro-structure dimensions to a size which encompasses many grain diameters, the resistance to fracture increases, in certain polycrystals, by a factor of 5–10. This increase represents the difference between the fracture resistance of the polycrystal and that of its individual constituent single crystals. In this chapter, we: (1) show how relatively small variations in grain size and shape affect the fracture toughness — crack size relationship (R-curve behaviour); (2) briefly review several microstructural mechanisms suggested to be responsible for both the high fracture energy of polycrystals and the rising resistance to fracture with crack extension; (3) present the results ofin-situmicroscopy observations of subcritically propagating cracks which lend support to crack-interface traction as an important fracture resistance mechanism; and (4) examine the complicating influence that the traction mechanism has on prediction of time-dependent failure from flaws propagating under the influence of stress-enhanced chemical reactions.
DOI：
10.1007/978-1-4613-2233-7
发表时间：
1986-12
期刊：
--
影响因子：
--
作者：
R. E. Tressler;G. Messing;C. Pantano;R. Newnham
通讯作者：
R. E. Tressler;G. Messing;C. Pantano;R. Newnham