A dislocation-based crystal viscoplasticity model with application to micro-engineered plasma-facing materials

JOURNAL OF NUCLEAR MATERIALS

卷:485

Article

Rivera, David¹  Huang, Yue¹  Po, Giacomo¹  Ghoniem, Nasr M.¹ 

[1] Univ Calif Los Angeles, Dept Mech & Aerosp Engn, 420 Westwood Plaza, Los Angeles, CA 90095 USA

关键词: Tungsten;    Thermomechanics;    Plasma transients;    Surface architecture;    Residual stress;   

DOI  :  10.1016/j.jnucmat.2016.12.034

来源: Elsevier

【 摘 要 】

Materials developed with special surface architecture are shown here to be more resilient to the transient thermomechanical environments imposed by intermittent exposures to high heat flux thermal loading typical of long-pulse plasma transients. In an accompanying article, we present experimental results that show the relaxation of residual thermal stresses in micro-engineered W surfaces. A dislocation-based model is extended here within the framework of large deformation crystal plasticity. The model is applied to the deformation of single crystals, polycrystals, and micro-engineered surfaces composed of a uniform density of micro-pillars. The model is utilized to design tapered surface micro pillar architecture, composed of a Re core and W coatings. Residual stresses generated by cyclic thermomechanical loading of these architectures show that the surface can be in a compressive stress state, following a short shakedown plasma exposure, thus mitigating surface fracture. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

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