Creep Fracture in Fibrous Microstructures

这项工作的目的是开发定向微观结构设计的预测方法，以便在高温下获得非常高的抗变形和抗破裂能力。该方法基于将界面处随时间变化的成核和空腔生长的局部原子机制，以及伴随空化的应力集中的长期弛豫与试样中成核位置的随机分布耦合在一起。提出的工作是实验和理论。研究结果将特别应用于高温氮化硅陶瓷。该提案旨在开发定向显微组织设计的预测方法，以获得非常高的抗高温变形和断裂能力。

9505859 Raj The objective of the proposed work is to develop predictive methods for the design of directional microstructures for the purpose of obtaining very high resistance to deformation and fracture at very high temperatures. The approach is based on coupling the local atomistic mechanisms of time dependent nucleation and growth of cavities at interfaces, and the long range relaxation of the stress concentrations accompanying cavitation, with the stochastic distribution of nucleation sites in the specimen. The proposed work is both experimental and theoretical. The results will be applied specifically to high temperature silicon nitride ceramic. %%% The proposal is aimed to develop predictive methods for the design of directional microstructures for the purpose of obtaining very high resistance to deformation and fracture at very high temperatures.