A dual-phase microstructural approach to damage and fracture of Ti3SiC2/SiC joints

JOURNAL OF NUCLEAR MATERIALS

卷:499

Article

Ba Nghiep Nguyen¹  Henager, Charles H., Jr.¹  Kurtz, Richard J.¹ 

[1] Pacific Northwest Natl Lab, POB 999,MSIN J4-55, Richland, WA 99352 USA

关键词: SiC;    Fusion materials;    Joining;    Swelling;    Neutron irradiation;    Thermal expansion;    Damage modeling;    Finite element;   

DOI  :  10.1016/j.jnucmat.2017.11.054

来源: Elsevier

【 摘 要 】

The microcracking mechanisms responsible for Ti3SiC2/SiC joint damage observed at the macroscopic scale after neutron irradiation experiments are investigated in detail. A dual-phase microstructural approach to damage and fracture of Ti3SiC2/SiC joints is developed that uses a finely discretized two-phase domain based on a digital image of an actual microstructure involving embedded Ti3SiC2 and SiC phases. The behaviors of SiC and Ti3SiC2 in the domain are described by the continuum damage mechanics (CDM) model reported in Nguyen et al., J. Nucl. Mater., 2017, 495:504-515. This CDM model describes microcracking damage in brittle ceramics caused by thermomechanical loading and irradiation-induced swelling. The dual-phase microstructural model is applied to predict the micro-cracking mechanisms occurring in a typical Ti3SiC2/SiC joint subjected to heating to 800 degrees C followed by irradiation-induced swelling at this temperature and cooling to room temperature after the applied swelling has reached the maximum swelling levels observed in the experiments for SiC and Ti3SiC2. The model predicts minor damage of the joint after heating but significant microcracking in the SiC phase and along the boundaries between SiC and Ti3SiC2 as well as along the bonding joint during irradiation-induced swelling and cooling to room temperature. These predictions qualitatively agree with the limited experimental observations of joint damage at this irradiation temperature. (c) 2017 Elsevier B.V. All rights reserved.

【 授权许可】

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